Concrete International Magazine March 2009

MARCH 2009 Vol. 31 No. No. 3

CIRCLE READER CARD #2




MARCH 2009 Vol. 31 No. 3

MIXING, PLACING, AND CURING

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41

48

Sustainability through Strength Integrating post-tensioned lateral systems and slag cement concrete for a model of environmental architecture by Mark Stevenson and Leo Panian Investigating Construction Methods for Longtan Dam An experimental study of surface treatments for roller-compacted concrete by Lei Yang and Jonathan J. Shi From Rheology of Fresh Concrete to Casting Processes Correlating properties with field performance by Nicolas Roussel

ALSO FEATURING

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23 53 57 86

ACI’s New Fellows Twenty-eight members to be honored in San Antonio Sloped Versus Stepped Footings for Walls Inspired by the Spirit of Concrete Highlights of the convention in St. Louis, MO Annual Index of Concrete International

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March Concrete international PUBLISHER Ward R. Malisch, PE ([email protected])

64

EDITOR-IN-CHIEF Rex C. Donahey, PE ([email protected])

departments

MANAGING EDITOR Keith A. Tosolt ([email protected]) ENGINEERING EDITOR Michael L. Tholen, PE ([email protected]) ASSISTANT EDITOR Jaime J. Novak-Fioritti ([email protected]) ADVERTISING Jeff Rhodes Network Publications, Inc. ([email protected]) PUBLISHING SERVICES

SUPERVISOR John Q. Horn EDITORS Carl R. Bischof ( Senior Editor ), Emily H. Bush, Karen Czedik GRAPHIC DESIGNERS Gail L. Tatum ( Senior Designer ), Susan K. Esper, Colleen E. Hunt, Ryan M. Jay PRODUCTION ASSISTANT Lindsay K. Kennedy ADMINISTRATIVE ASSISTANT Daniela A. Bedward

AMERICAN CONCRETE INSTITUTE http://www.concrete.org Tel. (248) 848-3700 Fax. (248) 848-3150 4

MARCH 2009

/ Concrete international

Workers place the roof deck concrete for the David Brower Center in Berkeley, CA. To minimize congestion and placement problems for the building’s post-tensioned core walls, No. 14 (No. 43) and No. 11 (No. 36) vertical bars were confined using headed transverse bars in lieu of conventional hooked bars and cross ties. For more on this project, see p. 34. (Cover photo courtesy of Tipping Mar +associates.)

7 8 10 16 18 56 69 73 76 77 78 79 80 81 82 83 84

President’s Memo Educational Seminars News Chapter Reports Calls for Papers What’s New, What’s Coming Products & Practice Special Products & Practice Showcase Industry Focus Meetings Standardization Spanish Translation Synopses Bookshelf Membership Application Bulletin Board Advertisers’ Index Concrete Q&A

Copyright © 2009 American Concrete Institute. Printed in the United States of America. All correspondence should be directed to the headquarters office: P.O. Box 9094, Farmington Hills, MI 48333-9094. Telephone: (248) 848-3700. Facsimile (FAX): (248) 848-3701. Concrete International (US ISSN 0162-4075) is published monthly by the American Concrete Institute, 38800 Country Club Drive, Farmington Hills, Mich. 48331. Periodicals postage paid at Farmington, Mich., and at additional mailing offices. Concrete International has title registration ® with the U.S. Patent Trademark Office. Subscription rates: $161 per year (U.S. and possessions); $170 (elsewhere) payable in advance: single copy price is $26.00 for nonmembers, $19.00 for ACI members, both prepaid. POSTMASTER: send address changes to Concrete International, P.O. Box 9094, Farmington Hills, MI 48333-9094. The Institute is not responsible for the statements or opinions expressed in its publications. Institute publications are not able to, nor intended to supplant individual training, responsibility, or judgment of t he user, or the supplier, of the information presented. Permission is granted by the American Concrete Institute for libraries and other users registered with the Copyright Clearance Center (CCC) to photocopy any article herein for the fee of $3.00 per transaction. Payments marked ISSN 0162-4075/97 should be sent directly to the Copyright Clearance Center, 21 Congress St., Salem, Mass. 01970. Copying done for other than personal or internal reference use without the express permission of the American Concrete Institute is prohibited. Requests for special permission or bulk copying should be addressed to the Publisher, Concrete International, American Concrete Institute. Canadian GST #126213149RT

American Concrete Institute Board of Direction President

Directors

Luis E. García Past President Board Members

Thomas D. Verti James R. Cagley David Darwin Vice Presidents

Florian G. Barth

March 2009

A

s ACI’s chartered objective states, the organization’s purpose is “to provide a comradeship in finding the best ways to do concrete work of all kinds and in spreading that knowledge.” If you attend an ACI convention, you know well that comradeship (also known as friendship and partnership) is a major reason we meet. This month’s CI includes a recap of events at the ACI Fall 2008 Convention held in St. Louis, MO. The text and photos only cover the highlights of the proceedings. While so much more takes place at technical sessions and committee meetings, we hope that this glimpse of the activities provides readers with a sense of the time, the place, the people, and the bonds they share. And that comradeship will once again be on display as we gather this month in San Antonio, TX, for the spring convention. Features and departments in this month’s CI provide practical tips on reinforcing detailing, a look toward a future in which computational modeling of flow could become a practical construction tool, and identification of methods to enhance interlayer bonding in roller compacted dams. It’s a diverse line-up fitting of a diverse industry and the organization that serves it. RCD

Colin L. Lobo Myles A. Murray Michael J. Schneider Andrea J. Schokker Eldon G. Tipping Kari L. Yuers

Claude Bédard Kenneth B. Bondy Ramón L. Carrasquillo Beverly A. Garnant S.K. Ghosh Charles S. Hanskat

Executive Vice President

Richard D. Stehly

T echnical Activities Committee

William R. Tolley

Educational Activities Committee

Certification Programs Committee

CHAIR

CHAIR

CHAIR

David H. Sanders

Cecil L. Jones

G. Terry Harris

SECRETARY

STAFF LIAISON

Daniel W. Falconer

Richard F. Heitzmann

John W. Nehasil

STAFF LIAISON

Sergio M. Alcocer Kenneth B. Bondy Chiara F. Ferraris Ronald Janowiak David W. Johnston Steven H. Kosmatka Michael E. Kreger David A. Lange Myles A. Murray Antonio Nanni Hani H. Nassif Michael Sprinkel

Richard P. Bohan Dean A. Browning Darrell F. Elliot Frank A. Kozeliski Kimberly E. Kurtis Thomas O. Malerk Stephen Pessiki William E. Rushing Jr. Andrea J. Schokker David M. Suchorski Kari L. Yuers

Ronald G. Burg Kenneth Caubble Mark A. Cheek Terry C. Collins Frances T. Griffith Marc Jolin Cecil L. Jones Colin L. Lobo Thomas O. Malerk Peter M. Maloney Jon I. Mullarky Roberto A. Nunez William D. Palmer Jr. Joseph E. Rottman John J. Schemmel

ACI Staff

Executive Vice President: William R. Tolley ([email protected]) Certification: John W. Nehasil, Managing Director ([email protected]) Customer and member support: Melinda G. Reynolds, Manager ([email protected]) Engineering: Daniel W. Falconer, Managing Director ([email protected]) Finance and administration: Donna G. Halstead, Managing Director ([email protected]) Publishing and event services: Renée J. Lewis, Director ([email protected])

Professional development: Richard F. Heitzmann, Managing Director ([email protected]) Sales and membership: Diane L. Baloh, Director ([email protected]) Strategic Development Council/ Marketing, sales, and industry relations: Douglas J. Sordyl, Managing Director ([email protected]) Systems, services and chapters: John C. Glumb, Managing Director ([email protected])

Sustaining Members

See pages 14-15 for a list of ACI’s Sustaining Members. To learn more about our sustaining members, go to the ACI Web site at www.concrete.org/members/mem_sustaining.htm.

Concrete international

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Your Help Made it Possible I

t has been a privilege to be the President of ACI during the 2008-2009 term that will end this month during the Spring Convention in San Antonio, TX. My year as Luis E. García, ACI President President would have been very difficult without the help of all ACI members, ACI’s excellent staff, and my companions on the Board of Direction and the Executive Committee. I know the silent volunteer work of ACI’s committees and chapters is our strongest quality and an example to other similar institutions. As you know, the recent economic downturn has had a far-reaching impact that has affected all of our members. The American Concrete Institute remains dedicated to supporting our members through these challenging economic times. With your support, we have been able to maintain the technical resources and membership benefits that you are familiar with and to continue new initiatives that are underway. ACI is committed to maintaining its role in the concrete industry during this uncertain economic climate. ACI has been advancing concrete knowledge since 1904, and while 2009 may be a difficult year, ACI will emerge as a stronger organization with even more to offer the industry and all members. The ACI Strategic Plan set the route to follow and the ACI leadership carefully adjusts the Institute’s short- and long-term objectives to respond to new issues and challenges. This has been an excellent management technique that has proven its worth through the years. Our system of electing a Vice President every year for a 2-year term acquaints that person with the inner workings of the Institute, preparing the future President to lead in a way that would be difficult to achieve otherwise. The existence of a dedicated st aff makes directing ACI a job without surprises. The support of staff strengthens the Institute’s ability to provide an environment where the continuity of the dedicated and unselfish volunteer work performed by all our members makes ACI a world leader in concrete technology. By electing me as the first ACI President not residing in North America, a new set of challenges and opportunities developed. Although ACI has a long-standing tradition of

interacting with concrete-related organizations worldwide, the enhancement of ACI’s international role was an obvious objective. The participation of international members in our committees has increased and our cooperation with code-writing bodies worldwide has generated valuable feedback regarding the use of ACI standards and the development of concrete standards worldwide. This has resulted in an increase in the number of official translations of ACI documents. The successful fifth International Workshop on Concrete in the Americas that took place during the Fall 2008 Convention in St. Louis, MO, proves the ability of ACI to maintain activities that are interesting for our international members. We will be seeing more of these activities in the future focused on other regions of the world. ACI membership has increased through novel approaches in enhancing membership value and benefits. The Institute is dedicated to making membership more attractive to young members every day. Establishing free e-membership for students has increased student membership to numbers never before seen. We want to see our young members more involved in our activities. The recently adopted policy to allow committee membership by students is just one of the many ways t o achieve this participation, as is increasing the number of available ACI Fellowships and Scholarships. The current pilot program underway to encourage certification activities for students will have far-reaching implications. ACI has been providing leadership in sustainable development in concrete. We will see this evolving under the leadership of Florian Barth, our next President. It may be the most important challenge in the near future for ACI. I would like to extend my “muchas gracias” to all ACI members, staff, and my companions on the Board of Direction and the Executive Committee for helping me direct ACI during this challenging and interesting year.

Luis E. García [email protected] Concrete international

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Spring 2009 ACI Educational Seminars seminars at-a-glance

For more information on ACI seminars, visit www.concreteseminars.com

ACI/PCA 318-08 BUILDING CODE One-day seminar for engineers, architects, specifiers, building officials, and others involved with structural concrete. Cosponsored by PCA, this intensive seminar wil l guide you step-by-step through the significant changes in the 2008 edition of the ACI 318 Building Code Requirements for Structural Concrete. Instructors will explain each change, why it was made, and what it means to you as a designer and specifier of structural concrete. A porti on of the day will be set aside to discuss Appendix D, Anchoring to Concrete. Examples will be presented to illustrate applications of the new Code provisions. Complimentary publications include: ACI 318-08, PCA Notes on 318, and seminar lecture notes. CONCRETE REPAIR BASICS One-day seminar for engineers, repair contractors, material suppliers, maintenance personnel, and public works engineers. Attendees will learn the best methods and materials for economical and effective concrete repairs. The seminar will cover causes and evaluation of problems in deteriorating concrete, repair techniques, repair materials, cracks and joints, protection systems, overlays, and specifications for structures. Complimentary publications include ACI 201.1R, ACI 224.1R, ACI 364.1R, ACI 437R, ACI 546R, and Course Notes.

DESIGN OF CONCRETE SLABS ON GROUND This one-day seminar will focus on the design of concrete slabs in accordance with ACI 360R , “Design of Slabs-onGround.” The purpose of the seminar is to provide engineers and designers with practical tools and information that can be used right away for slab design. The seminar will cover soil support systems, materials, issues dealing with curling, various design methods, reinforcing, joint spacing, designing for flatness and levelness, surface treatments, and much more. Instructors will work through several design examples. Complimentary publications include ACI 360R and Course Notes.

Learning

e

Check out ACI’s new eLearning opportunities at acielearning.org . In addition to the certification training that is already available, technical topics will be added in the coming months.

CONTINUING EDUCATION CREDIT Seminar attendees will receive 0.75 Continuing Education Units (CEUs), worth 7.5 Professional Development Hours (PDHs). Professional Engineers can convert CEUs to PDHs to fulfill their continuing education requirements. ACI is a Registered Provider with the American Institute of Architects, and several state licensing boards.

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seminar dates and locations

For additional dates and locations or more information on ACI seminars, visit www.concreteseminars.com Dates are subject to change.

CHANGES IN 318-08 BUILDING CODE One-day seminar

(3189)

Detroit, MI March 3, 2009 Salt Lake City, UT March 5, 2009 Cincinnati, OH March 10, 2009 San Antonio, TX March 19, 2009 Baltimore, MD March 26, 2009

MIS

Jacksonville, FL March 31, 2009 Omaha, NE April 2, 2009 Indianapolis, IN April 7, 2009 Nashville, TN April 21, 2009 Pittsburgh, PA April 23, 2009

ITS OHS SAS MDS

CONCRETE REPAIR B ASICS One-day Seminar

Milwaukee, WI April 28, 2009 Philadelphia, PA April 30, 2009 Boston, MA May 5, 2009 Atlanta, GA May 7, 2009 Chicago, IL May 12, 2009

JAS NES INS TNS PAS

WIS PHS MAS ATS ILS

DESIGN OF CONCRETE SLABS ON GROUND One-day Seminar

(REP9)

New Orleans, LA March 25, 2009 New Brunswick, NJ April 1, 2009 Denver, CO April 22, 2009 San Francisco, CA April 29, 2009 Cincinnati, OH May 13, 2009

St. Louis, MO March 5, 2009 Chicago, IL March 26, 2009 San Diego, CA April 2, 2009

LAS NJS COS

(SLD9) MOS ILS CAS

CAS OHS

Fall 2009 seminars to be announced soon. Please check www.concreteseminars.com for further updates.

Register for two seminars in the same city on consecutive days and receive a special discount. Phone (248) 848-3815 for details. To register, please circle date and location above. See www.concreteseminars.com or phone (248) 848-3815. Complete this form and fax, mail, or phone as shown below. (CODE: CI) 012609.

seminar registration registration fee

ACI One-Day Seminars

ACI/PCA One-Day 318-08 Building Code

•$597 Registration Fee •$457 ACI National Members •$125 Full-Time Students

•$597 Registration Fee •$457 ACI National Members and Employees of PCA Member Firm Registration Fee •$125 Full-Time Students

To qualify for the discounted ACI National Member Seminar Fee, please provide your six-digit ACI Member number next to your name below. Discounted student seminar fee is only for full-time students under the age of 28. Include current proof of enrollment with your registration.

Name:

Registration Fee: $

Company:

Total Registration Fees: $

Address: Phone Number:

register today

City, State, Zip: Fax Number: Make checks payable to ACI, or charge to:

E-mail: VISA

MASTERCARD

By web: www.concreteseminars.com By mail: Member Services P.O. Box 9094 Farmington Hills, MI 48333-9094 By fax:

(248) 848-3801

By phone: Member Services (248) 848-3815 8:00 - 5:00 ET (Monday-Friday)

account no.

exp. date

Charge to my ACI member account (current ACI National Members only). Registration from all others must be accompanied by full payment, charged to a credit card, or reserved by government or company purchase order (ACI Federal ID No. 38-0296490). All payments must be in U.S. funds. I have a disability and may require accommodation in order to fully participate in the seminar.


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ASIAN CONCRETE FEDERATION CONFERENCE In November 2008, ACI Executive Vice President William R. Tolley attended the Third International Asian Concrete Federation (ACF) Conference hosted by the Vietnam Concrete Association in Ho Chi Minh City, Vietnam. During that visit, he met with incoming ACF President Jongsung Sim to explore ways that ACF and ACI could open up the lines of communication and possibly develop a memorandum of understanding between the two organizations. Tolley met with Jenn-Chuan Chern, Deputy Minister of the Public Construction Commission, Executive Yuan, Taiwan, and other ACI members at the ACF Conference reception. Chern is also President of the Taiwan Concrete Institute and Past President of the ACI Taiwan Chapter. ACI also signed an International Partnership Agreement with the Vietnam Concrete Association (VCA). Tong Van Nga, President of VCA, signed on behalf of the association.

Incoming ACF President Jongsung Sim (left) with ACI Executive Vice President William R. Tolley

Meeting with ACI members at the ACF Conference

Signing of the International Partnership Agreement with VCA President Tong Van Nga and ACI Executive Vice President William R. Tolley. Standing behind, from left, are Dang Hoang Huy, Phan Khac Long, Nguyen Van Chanh, Quang Hung, and Tran Ba Viet

NEW ACI PUBLICATIONS ACI announces the availability of four new publications and CD-ROMs:  “Code Requirements for Reinforced Concrete Chimneys and Commentary (ACI 307-08)” gives material, construction, and design requirements for concrete chimneys, including minimum loadings for design; price: $58.50 (ACI members $36.00); available in PDF format;  “Guide for the Design and Construction of Concrete Parking Lots (ACI 330R-08)” includes information on site investigation, thickness determination, design of joints and other details, durability considerations, paving operations, and quality assurance procedures during construction; price: $65.50 (ACI members $40.00); available in PDF format;

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“Guide to Fiber-Reinforced Shotcrete (ACI 506.1R-08)” describes the technology and applications of fiberreinforced shotcrete (FRS) using synthetic and steel fibers. Proportions of typical mixtures, batching, mixing, and application procedures are described, including methods of reducing rebound and equipment used to apply FRS; price: $40.50 (ACI members $25.00); available in PDF format; and  “Guide for Specifying, Proportioning, and Production of Fiber-Reinforced Concrete (ACI 544.3R-08)” covers specifying, proportioning, mixing, placing, and finishing of fiber-reinforced concrete; price: $43.50 (ACI members $27.00); available in PDF format. Call (248) 848-3800 or order online at www.concrete.org . 

PTI ELECTS NEW OFFICERS AND BOARD The Post-Tensioning Institute (PTI) has elected Kenneth Bondy, a consulting structural engineer, as President. He is a member of the ACI Board of Direction and the Technical Activities Committee. Other officers are Edward Hohman, Post-Tension of Nevada, Inc., Vice President; Russell Price, Suncoast Post-Tension, Ltd., Secretary; and Larry Krauser, General Technologies, Inc., Treasurer. All will serve a 2-year term in their respective positions. The Executive Committee includes the new officers and Scott Greenhaus, VSL, Past President; Paul Hohensee, ENERPAC, Associate Member Representative; and James Cagley, Cagley and Associates, Inc., Professional Member Representative. Joining the board are the following individuals: Cary Kopczynski, Cary Kopczynski & Co., Inc., Professional Member Representative; Thomas Mathews, Thomas F. Mathews Co., LLC, Affiliate Representative; Andy Kochis, Ready Cable, Inc.; Guy Cloutier, Harris P/T; Dawn Kori, Post Tension Cables, Inc.; and Travis Gilpin, Consolidated Reinforcement, L.P. For more information, visit www.post-tensioning.org.

PCA CHAIRMAN ELECTED The Portland Cement Association (PCA) Board of Directors elected Enrique Escalante to serve a 2-year term as Chairman, succeeding Charlie Sunderland of Ash Grove Cement Company. Escalante is the President of GCC of America, Denver, CO. He joined GCC in 1999 as President of its Mexican division, moving to his current position in 2000. Prior to joining GCC, Escalante had more than 20 years of experience in management and sales positions in heavy industry and construction materials. In addition to serving as PCA’s

Kenneth Bondy

Enrique Escalante

Vice Chairman for the past 2 years, Escalante chaired the Research and Technical Council and Product Standards and Technology Committee. He was a member of the Regional Promotion and Publications Committees. Escalante received an engineering degree from the Technologic Institute of Monterrey and an MBA from Cornell University. Aris Papadopoulos, CEO of Titan America, the U.S. subsidiary of Titan Cement Group, was elected Vice Chair. He also chairs the PCA Sustainable Development Committee. Papadopoulos has served as CEO of Titan America since 2000. Prior to that, he was CEO of Titan’s joint venture subsidiary, Roanoke Cement Company. Papadopoulos received a BS and an MS in chemical engineering from Massachusetts Institute of Technology and an MBA from Harvard.

TCA ALPHONSE ENGELMAN SAFETY AWARDS The Tilt-Up Concrete Association (TCA) Alphonse Engelman Safety Awards were presented at TCA’s Annual Meeting, held in conjunction with World of Concrete February 5, 2009, in Las Vegas, NV. The TCA Safety Awards Program was refined last year to better represent the diversity and size of the companies involved in TCA membership. The Best Tilt-Up Safety Achievement Award recognizes firms in several categories (General Contractor or Tilt-Up Subcontractor; Hours <100K, 100 to 250K, and >250K) with the lowest incident rate in 2007. The winners are: General Contractor



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(<100K), Newcomb Construction Company, Inc.; General Contractor (>250K), SB Ballard Construction Company; Tilt-Up Contractor (<100K), Cornerstone Construction Services, Inc., and Neyer Construction, Inc.; and Tilt-Up Contractor (>250K), MK Concrete Construction. Zero Lost Time Accident Achievement Awards went to Cornerstone Construction Services, Inc.; Newcomb Construction Company, Inc.; Neyer Construction, Inc.; Citadel Contractors, Inc.; MK Concrete Construction; and Vantage Construction Corp.

ENTRIES CLOSING FOR PCI COMPETITION Applications for university teams competing in the annual Engineering Student Design Competition conducted by the Precast/Prestressed Concrete Institute (PCI) are due March 15, 2009, with results to be completed by June 15. The “Big Beam” competition offers $25,000 in prize money. Teams are challenged to design, fabricate, and test a precast, prestressed concrete beam with the help of a faculty advisor and a local precast concrete Producer Member. Prizes are awarded for most efficient design, highest load capacity, best report, and other categories. Application materials and rules can be downloaded at www.pci.org/education/big_beam/index.cfm.

IN MEMORIAM Franco Levi , Honorary President of CEB and FIP, ACI Honorary Member, and Professor Emeritus of the Polytechnic of Turin, passed away on January 10, 2009, at the age of 94. A graduate of the Ecole Centrale in Paris and the Polytechnic of Milan, Levi started his academic career in 1937. After a period of exile in France and Switzerland, he returned to the Polytechnic of Turin in 1945, where he started developing his outstanding research work in structural mechanics and engineering and published well-known papers and books on elastic stress states induced by imposed and inelastic strains, nonlinear analysis, time-dependent effects in concrete structures, with specific regard to creep and shrinkage, and the conceptual bases of what was then the novel technique of prestressed concrete. Levi was appointed President of the Comité Européen du Béton (CEB) in 1957 and maintained this position until 1968, leading the organization to the publication of the first and second set of CEB Recommendations, the forerunners of modern CEB Model Codes, while expanding the action of CEB beyond its European borders. Between 1966 and 1970, Levi was also President of the Fédération Internationale de la Précontrainte (FIP). The American community of scholars of reinforced and

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prestressed concrete recognized the importance of his mission and ACI granted him Honorary Membership in 1965. In 1979, the European Union considered that the work of CEB might become the proper basis for the first Eurocode, and Levi was appointed Chairman of the Drafting Committee for Eurocode 2 on Concrete Structures. He also had an essential role in coordinating the creation of five other structural Eurocodes concerning different construction techniques. Levi’s constant attention to new achievements in research, his original contributions, perseverance, and enthusiastic work made him the real father of the Eurocodes. George W. Housner , often considered the father of earthquake engineering, died November 10, 2008, at the age of 97, in Pasadena, CA. Housner was a founding member of the Earthquake Engineering Research Institute, and a medal is given by the organization each year in his name. He was also instrumental in the formation of the International Association for Earthquake Engineering and Caltechs Earthquake Research Affiliates. Housner was Braun Professor of Engineering, Emeritus, at the California Institute of Technology. Donald Goldberg, Senior Vice President and Chief Engineer of Dewberry’s northeast operations, passed away September 28, 2008. He was 78 years old. Throughout his 44-year career at Dewberry, he was a staunch advocate of quality processes and cont rol. Goldberg was instrumental in the development of New Jersey’s transportation systems, serving as a lead designer on many projects. He was also a Past President of the American Council of Engineering Companies New Jersey chapter. Goldberg was active with ACI and a Life Member and Chairman of the PCI committee on bridges.

ADDITIONS TO THE 2008 SPECIFIERS’ PRODUCT GUIDE Please add the following companies to the Specifiers’ Product Guide, published in the December 2008 issue of Concrete International : Floor and slab treatments Penetrating floor hardener (reactive) Lythic Solutions (360) 694-5347 www.lythic.net Underlayments Modified cement-based; Portland cement-based Legacy Cements (516) 558-7139 www.legacycements.com


are the foundation of our success. To provide additional exposure to ACI Sustaining Members, Concrete International includes a 1/3-page member profile and a listing of all Sustaining Member organizations. All Sustaining Members receive the 1/3-page profile section on a rotating basis.

ACS Manufacturing Corporation

Kleinfelder

ALJANS

Lafarge North America

Allen Engineering Corp.

Lehigh Portland Cement Co.

ALLFLAT

Lithko Contracting, Inc.

Ash Grove Cement Company

Meadow Burke

Ashford Formula

W. R. Meadows, Inc.

Baker Concrete Construction, Inc.

Metromont Corporation

BASF Admixtures, Inc.

Municipal Testing Lab

BCS

Nox-Crete Products Group

Boral Material Technologies, Inc.

OMYA Canada, Inc.

Buzzi Unicem

Operating Engineers Training Trust

Cantera Concrete Company

Oztec

Cemex Inc.

PNA Construction Technologies, Inc.

CHRYSO-ProMix Technologies

Portland Cement Association

Commercial Contracting Corporation

Propex Concrete Systems

Concrete Engineering Specialists

Precast/Prestressed Concrete Institute

Concrete Reinforcing Steel Institute

Ruentex Group

CTLGroup

Scofield

Dayton Superior

Seretta Construction, Inc.

e-construct

Sika Corp.

The Euclid Chemical Co.

S.K. Ghosh Associates, Inc.

Expanded Shale, Clay & Slate Institute

Spurlino Materials

FGC, Inc.

Structural Group

Fibercon International, Inc.

Structural Services, Inc.

Francis Harvey & Sons

Triad Engineering, Inc.

Future Tech Consultants

Tru Wall Concrete, Inc.

W.R. Grace & Co.

Unibeton Readymix

Headwaters Resources, Inc.

Universal Concrete Products, Ltd., Co.

Holcim (US) Inc.

Wacker Neuson

ICS Penetron

Webcor Concrete

IDRA SA

Westroc, Inc.

Boral Material Technologies, Inc., (BMTI) is a leading marketer of fly ash and all coal combustion products. With more than four decades of experience marketing fly ash to the concrete industry, Boral is a pioneer in the development of new construction material technologies. Ready mixed concrete producers and contractors improve their operations with the aid of BMTI’s supply reliability, technical expertise, and sales and service support. BMTI also provides coal-fired power generating plants with complete on-site ash handling and management, environmental services, and engineering services. BMTI is not only successful in marketing fly ash, but also helps utility plants use all of their coal combustion products through innovative marketing and product development. For more information about Boral Material Technologies, Inc., visit www.boralmti.com or call 800-964-0951.

Keystone Structural Concrete, Ltd.

To learn more about our sustaining members, visit our Web site at www.concrete.org/members/mem_sustaining.htm

Lafarge is the largest diversified supplier of construction materials in the United States and Canada. We produce and sell cement, ready mixed concrete, gypsum wallboard, aggregates, asphalt, and related products and services. Lafarge believes that sustainability can be a competitive advantage. This long-term perspective includes the need for economic, social, and environmental consideration in our daily business decisions. We believe this approach will help us achieve our objectives to be the preferred supplier, community partner, employer, and investment. Lafarge is exploring ways to contribute to sustainable building. Our memberships in the U.S. Green Building Council and Canada Green Building Council demonstrates the company’s interest in partnering with “leaders from across the industry working to promote buildings that are environmentally responsible, profitable and healthy places to live and work.” Our products play a decisive role in sustainable architecture and construction. They are contributing a sustainable component to a growing number of LEED® projects across North America. Lafarge’s employees are also entering the LEED Professional Accreditation Program, earning the designation of LEED Accredited Professional, to better serve the environmental needs of the design and building community. For more information about Lafarge, visit www.larfarge.com or call 703-480-3600.

The Precast/Prestressed Concrete Institute (PCI), founded in 1954, is the foremost developer of standards and methods for designing, fabricating and constructing precast concrete structures. PCI also operates the world’s leading certification program for firms and individuals in the precast concrete structures industry. PCI publishes a broad array of periodicals, technical manuals, reports, and other informational documents, including an awardwinning technical journal. It also conducts educational seminars, technical conferences, conventions, exhibitions, and award programs. Institute members include firms comprising the precast concrete structures industry as well as architects, consultants, contractors, developers, educators, engineers, material suppliers, service providers, and students. PCI has 11 regional affiliates across the U.S. and maintains relationships with other organizations, both national and worldwide, having an interest in precast concrete. For more information about PCI visit www.pci.org or call 313-786-0300.

W. R. MEADOWS, INC., designs, manufactures, and markets highquality products and systems for today’s construction professionals. Products are sold through our authorized distribution network. We have multiple branch locations located throughout North America, and our products are available in overseas markets as well. Our products cover every facet of the construction industry—from protecting and sealing concrete, expansion joints, and concrete restoration, to blocking the ingress of moisture through the building envelope, we’re there. From highway construction and restoration, to waterproofing, vaporproofing, air barrier products, and more, we’ve been satisfying the needs of the public and private sectors of the building construction industry since 1926. All of our quality W. R. MEADOWS products are available worldwide through an authorized distributor network. We remain committed to producing environmentally friendly products and systems that meet or exceed the latest EPA standards and guidelines. Our GREEN LINE® of environmentally friendly products has been a cornerstone of our product line for over 25 years. For more information about W. R. MEADOWS, visit www.wrmeadows.com .

BRITISH COLUMBIA On October 21, 2008, the ACI British Columbia (BC) Chapter, with support from the American Shotcrete Association (ASA), held a “Structural Shotcrete Forum” for 80 attendees. This session was provided as a result of the recent dramatic increase in structural shotcrete use in the lower mainland region of British Columbia (and now also in the Calgary, AB, market) and requests from the industry for a forum to review and discuss all aspects of the design, supply, installation, inspection, and testing of structural shotcrete. The forum opened with a general introduction to structural shotcrete followed by a guide to preparing “Structural Shotcrete Specifications” by D.R. (Rusty) Morgan, FACI, AMEC Earth & Environmental, and immediate Past President of ASA. Levi Stoelting, Glotman Simpson Consulting Engineers, discussed “Structural Shotcrete: Structural Engineers Perspective,” drawing from his experience in the structural design and construction of deep below-ground structural shotcrete walls for parking structures in the Southern California market and now Western Canada. Mike Meacher, Lafarge Canada, Inc., and current President of the ACI BC Chapter, spoke on his experience in lower mainland BC regarding “Ready Mix Shotcrete Design and Supply.” Roland Heere, Metro Testing Laboratories Ltd., covered “Shotcrete Quality Control Inspection and Testing.” Ross King, Conshot Systems, Inc., gave an enlightening presentation on “Structural Shotcrete Construction in Western Canada.” He was able to demonstrate the great strides that have been made in structural shotcrete construction in Western Canada in the past few years. Finally, Chris Zynda, JJ Albanese, and current President of ASA, provided an informative presentation on the historical and current use of structural shotcrete in California. The forum concluded with an open discussion session. A general “Shotcrete Seminar” was featured in the afternoon. Rusty Morgan and Chris Zynda gave a joint presentation on “Shotcrete: A Versatile Construction Solution” in which they showcased the many and various uses of shotcrete from their combined 65 years of shotcrete experience. Neil McAskill, Metro Testing Laboratories Ltd., gave a presentation on “Shotcrete Rehabilitation of Historic Masonry Structures.” ASA Past President Peter Tatnall, FACI, Performance Concrete Technologies, and immediate Past Chair of ACI Committee 506, Shotcrete, gave a presentation on “Fiber-Reinforced Shotcrete,” bringing the audience up to date on the technology for both steel and synthetic fiber-reinforced

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shotcrete. The seminar concluded with a presentation on “Shotcrete Shoring in the Lower Mainland BC” by Roger Abbott, Abbott Shoring and Foundations Ltd., who has just completed the largest shotcrete shoring job ever undertaken in Canada: the 14 km (8.5 mile) long cut and cover section of the new Canada Line rapid transit line from Vancouver Airport to downtown Vancouver. This forum and seminar proved to be an excellent example of collaboration between ACI and another industry association, in this case ASA, to further advance technology dissemination. GREATER MICHIGAN Douglas J. Sordyl, ACI Managing Director, Strategic Development Council/Marketing, Sales, and Industry Relations, is the 2008 recipient of the chapter’s Arthur Y. Moy Memorial Award. Moy was the Chief of the Structural Bureau for the City of Detroit Department of Buildings and Safety Engineering. When he died in 1967, he was the incoming President of the ACI Michigan Chapter. In his memory, the chapter established the Arthur Y. Moy Memorial Award in 1968 and the first plaque was presented to his wife in 1969. The award is given to an individual in the chapter area who has contributed substantially to the advancement of concrete technology.

Douglas J. Sordyl (left) receives the Arthur Y. Moy Memorial Award from Ken Lozen, Treasurer, ACI Greater Michigan Chapter

NEW STUDENT CHAPTER A new ACI student chapter was recently formed at the South Dakota School of Mines and Technology. The elected officers are Julian Koerner, President; Ken Collins,

Vice President; Craig Phillips, Secretary; and Brady Wiesner, Treasurer. Advisors for the chapter are M.R. Hansen and Damon Fick. The first activity of the chapter was to travel to St. Louis, MO, to attend the ACI Fall 2008 Convention. On the way, the group visited Gage Brothers precast concrete plant in Sioux Falls, SD. The group also visited several large bridges around St. Louis with Dena Guth, a bridge engineer. At the ACI convention, the group attended technical sessions and committee meetings, and displayed their new banner with ACI President Luis E. García.

S.F.A. Rafeeqi (left), President, ACI Pakistan Chapter, and Abul Kalam (right), Vice Chancellor, NED University of Engineering & Technology, presented Syed Tanvir Wasti with a memento after his lecture

ALWAYS OPEN You’ll never have to wait for ACI’s Online Bookstore to open. Our collection of over 400 standards, technica l reports, special publications, and industr y favorites is always open—waiting for you!

The South Dakota School of Mines and Technology ACI Student Chapter at the ACI Fall 2008 Convention, from left: Advisor M.R. Hansen, Brady Wiesner, Craig Phillips, Julian Koerner, ACI President Luis E. García, Ken Collins, and Advisor Damon Fick

Additionally, you can download many of ACI’s publications immediately!

ACI’s Online Bookstore—it’s always open!

www.concrete.org

PAKISTAN The ACI Pakistan Chapter organized a technical lecture titled “150 Years of Concrete” at NED University of Engineering & Technology, Karachi, Pakistan, on November 11, 2008. The invited speaker was Syed Tanvir Wasti, Professor Emeritus, Department of Civil Engineering, Middle East Technical University, Ankara, Turkey. His lecture was a pictorial and historical account of the development of reinforced concrete. It dealt with the milestones in the progress of concrete technology, highlighting the names of those who have made significant contributions. The objective of the lecture was to stimulate greater interest in reinforced concrete and its structural possibilities, based on previous theoretical and applied work. The lecture was attended by consulting engineers, contractors, faculty members, and graduate and undergraduate students. Concrete international

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TEMPERATURE EFFECT ON CONCRETE PERFORMANCE Meeting: Technical session on “Temperature Effect on Concrete Performance and Durability” at the ACI Fall 2009 Convention, November 8-12, 2009, New Orleans, LA; sponsored by ACI Committee 236, Material Science of Concrete. Solicited: What effect does temperature have on curing and subsequent properties and performance of concrete? How can temperature be controlled and even optimized to produce the best possible outcomes in terms of short-term property development and long-term durability and lifecycle performance? Papers are sought on topics such as modeling temperature changes in concrete from the time of mixing on; microstructural and transport properties of concrete cured under various conditions and the effects of temperature on durability performance; and field studies on temperature effects and case studies of in-place concrete where the curing history is known. Requirements: Submit paper title and abstract. Deadline: Abstracts by March 6, 2009. Send to: J.J. Biernacki, e-mail: [email protected]; or J. Olek, e-mail: [email protected].

FRACTURE MECHANICS Meeting: 7th International Conference on Fracture Mechanics of Concrete and Concrete Structures (FraMCoS-7), May 23-28, 2010, Seogwipo City, Jeju, Korea.

See the eve nts calendar at www.concreteinternational.com for more listings.

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Solicited: Papers are invited on conference topics that include fracture and cracking behavior of concrete structures, highperformance and high-strength concrete, fiber-reinforced cementitious composites, structural monitoring and assessment, repair and retrofitting, advancement in structural design codes, interface fracture and debonding phenomena, and practical applications of fracture mechanics. Requirements: Prospective authors are invited to submit a onepage detailed abstract following the guidelines provided on the FraMCoS-7 Web site at www.framcos7.org. Abstracts should be submitted through the conference Web site. Deadlines: Abstracts by March 31, 2009. Contact: [email protected].

SUSTAINABLE CONSTRUCTION Meeting: Conference on Sustainable Construction Materials and Technologies, June 28-30, 2010, Università Politecnica Della Marche, Ancona, Italy. Solicited: The conference theme will cover the sustainability of all construction materials with renewed emphasis on limiting their carbon footprint. Papers are invited on all the different materials that are used in construction including aggregates, bitumen, cementitious materials, (fly ash, wood ash, slag, silica fume, natural pozzolans, and other similar materials), concrete, glass, gypsum, lime, masonry, metals, plastics, rock, and timber. Further details are available from the conference Web site: www.uwm.edu/dept/cbu/ ancona.html. Requirements: Submit an abstract of 200 to 300 words along with author/speaker name(s), affiliation, mailing address, telephone, and

e-mail. Abstracts should be submitted by e-mail. Deadlines: Abstracts by April 17, 2009; final papers are due January 10, 2010. Send to: [email protected].

CONCRETE UNDER SEVERE CONDITIONS Meeting: Sixth International Conference on Concrete under Severe Conditions—Environment and Loading (CONSEC’10), June 7-9, 2010, Mérida, Yucatán, México. Solicited: Original papers are sought in areas including, but not limited to, sustainability, emerging fields, maintenance and repairs, codes and design, concrete construction, performance under severe loading, specialized materials, and performance under severe environments. Requirements: Submit a 300-word abstract through the conference Web site at www.consec10.com. Deadline: Abstracts by March 31, 2009. Contact: Direct inquiries to [email protected].

EARTHQUAKE ENGINEERING Meeting: Ninth U.S. National and Tenth Canadian Conference on Earthquake Engineering: Reaching Beyond Borders, July 25-29, 2010, Toronto, ON, Canada. Solicited: This conference will bring together professionals from a broad range of disciplines, including architecture, structural engineering, seismology, geology, geophysics, geotechnical engineering, social response, regional planning, emergency response planning, and regulation. Topics of the technical program will include ground motion, seismicity, seismic hazard assessment, and seismic risk; soils, foundations, soilstructure interaction, and soil

stability; buildings, structural, and nonstructural systems; bridge structures; seismic isolation, energy dissipation, and control systems; post-earthquake response, damage assessment, and recovery; repair and retrofit of structures and foundations; socioeconomic issues, education, and public policy; lessons learned from recent earthquakes; and experimental methods, information technology, and collaborative tools. Requirements: Submit an abstract no longer than 500 words by visiting the conference Web site: http:// 2010eqconf.org/. Deadline: Abstracts by March 31, 2009. Contact: For more information, visit http://2010eqconf.org/.

SYMPOSIUM ON MASONRY Meeting: ASTM International Symposium on Masonry, June 8, 2010, St. Louis, MO; sponsored by ASTM International Committees C01, Cement; C07, Lime; C12, Mortars and Grouts for Unit Masonry; and C15, Manufactured Masonry Units. The symposium will be held in conjunction with the June 8-11, 2010, standards development meetings of the committees. Solicited: The objective of the symposium is to gather and disseminate the latest information on all aspects of innovations in masonry materials, design, specification, construction, maintenance, and rehabilitation. It will emphasize the application of ASTM standards to those areas, and their coordination with building codes, project specifications, and international standards. The scope of the symposium covers the usage, constructibility, selection, or specification of masonry materials or workmanship as they relate to masonry construction, research,

restoration, innovative techniques, or new materials. Requirements: To participate in the symposium, authors must use the online abstract submittal form at www.astm.org/MEETINGS/ COMMIT/c01cfp0610.htm and attach a 250- to 300-word preliminary abstract. The abstract must include a clear definition of the objective and approach of the work discussed, pointing out material that is new, and present sufficient details regarding results. The presentation and manuscript must not be of a commercial nature nor can it have been previously published. Deadline: Abstracts by April 4, 2009. Contact: Additional information is available from symposium Cochairs Bill Behie, Holcim (US), Inc., Huntersville, NC; telephone: (704) 947-5700; e-mail: bill.behie@holcim. com; and Jamie Farny, Portland Cement Association, Skokie, IL; telephone: (847) 972-9172; e-mail: [email protected].

OUR WORLD IN CONCRETE AND STRUCTURES Meeting: 34th Conference on Our World in Concrete and Structures, August 16-18, 2009, Singapore. Solicited: Original papers on the theme of “Green Concrete” are invited. Other topics to be covered at the conference include, but are not limited to, design and analysis for buildings and structures; mixture proportions, quality control, and production; prefabrication; concrete plant, equipment, and machinery; repair and rehabilitation; and materials and composites. Requirements: Submit an abstract on one A-4 page. Deadline: April 15, 2009. Send to: Secretariat, CI-Premier Pte Ltd, 150 Orchard Road #07-14,

Orchard Plaza, Singapore 238841; telephone: +65-6733-2922; fax: +656235-3530; e-mail: cipremie@singnet. com.sg; Web site: www.cipremier.com. fib CONGRESS Meeting: The third international fib Congress and Exhibition, May 29June 2, 2010, Washington, DC; to be held in conjunction with the Precast/ Prestressed Concrete Institute Annual Convention and Bridge Conference. Solicited: The event is organized around the theme of “Think Globally, Build Locally.” Technical sessions will cover a wide range of topics including innovative structures, seismic design, FRP reinforcement, durability, safety issues, connections, anchorages, and much more. Requirements: Individuals wishing to present a paper or poster during a technical session can submit abstracts via the congress Web site at www. fib2010washington.com. Deadline: Abstracts by April 15, 2009. Contact: Direct inquiries to info@ fib2010washington.com.

FOUNDATIONS FOR RENEWABLE ENERGY STRUCTURES Meeting: Technical session on “Equipment Foundation Design for Renewable Energy Structures” at the ACI Spring 2010 Convention, March 21-25, 2010, Chicago, IL; sponsored by ACI Committee 351, Foundations for Equipment and Machinery. Solicited: Presentation topics include, but are not limited to, the design, analysis, and construction of equipment foundations unique to wind power, ocean energy, and solar energy structures. Requirements: 1) Presentation title; 2) author/speaker name(s), mailing address, telephone, fax, and Concrete international

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REQUEST FOR K-12 RESOURCES FOR CONCRETE

e-mail; and 3) an abstract of 200 to 300 words. Presentations should follow ACI presentation guidelines and format. Deadlines: Abstracts by April 30, 2009; final papers are due December 1, 2009. Send to: Patricia Warren, Southern Company Generation, 42 Inverness Center Parkway/Bin B453, Birmingham, AL 35242; telephone: (205) 992-6347; fax: (205) 992-6411; e-mail: pbwarren@ southernco.com.

MAINTENANCE AND REPAIR OF BRIDGES Meeting: Technical session on “Recent Advances in Maintenance and Repair of Concrete Bridges” at the ACI Spring 2010 Convention, March 21-25, 2010, Chicago, IL; sponsored by ACI Committee 345, Concrete Bridge Construction, Maintenance, and Repair. Solicited: The special session will focus on current technology for concrete bridge repair and maintenance. The presentations and technical papers will include case studies of damage and corresponding repair due to extreme events, stateof-the-art repair technologies, evaluation and inspection techniques, and maintenance of existing concrete bridges. The technical session will provide critical information to practicing engineers, government officials, and academics. An ACI Special Publication will be published. Requirements: 1) Presentation/ paper title; 2) author/speaker name(s), title, organization, mailing address, telephone, fax, and e-mail; and 3) an abstract of 200 words. Deadlines: Abstracts by May 20, 2009; final papers are due by August 30, 2009. Send to: Yail J. Kim, North Dakota State University, 1410 14th Ave. N, Department of Civil Engineering, 20

MARCH 2009


Fargo, ND 58105; telephone: (701) 231-6394; fax: (701) 231-6185; e-mail: [email protected].

BRIDGE MAINTENANCE, SAFETY, AND MANAGEMENT Meeting: Fifth International Conference on Bridge Maintenance, Safety, and Management, July 11-15, 2010, Philadelphia, PA. Solicited: All major aspects of bridge maintenance, safety, and management will be addressed, including, but not limited to, advanced materials, assessment and evaluation, bridge diagnostics, design for durability, emerging technologies, nondestructive testing, prediction of future traffic demands, safety and serviceability, sustainable bridges, and whole life costing. Visit www. iabmas2010.org for more information on the conference topics. Requirements: Submit a 300-word abstract to the Conference Secretariat together with the preliminary registration form. Abstracts should be submitted in electronic form as either a plain text or Word attachment to the conference Web site. Deadlines: Abstracts by May 31, 2009; final papers are due November 30, 2009. Contact: Mary Ann Cahalan, Conference Coordinator, Lehigh University, ATLSS Engineering Research Center, 117 ATLSS Drive, Bethlehem, PA 18015; telephone: (610) 758-3468; e-mail: secretariat@ iabmas2010.org.

HOW I SPICED UP MY CONCRETE Meeting: Technical session on “How I Spiced up my Concrete” at the ACI Fall 2009 Convention, November 8-12, 2009, New Orleans, LA. Solicited: Authors are encouraged to submit an abstract related to various ways they have “spiced up” their

ACI Committee E802, Teaching Methods and Educational Materials, is collecting resources detailing activities and teaching resources for concrete material, construction, and design appropriate for Kindergarten through Grade 12. ACI would like to make this collection of K-12 educational materials available for teachers to incorporate concrete into their curriculums. If you are aware of any resources that may be appropriate, please forward the information to Laurel Dovich, P.O. Box 8426, Spokane, WA 99203; e-mail: laurel.dovich@ wallawalla.edu.

concrete with innovations in research, design, materials, and construction methods. The Technical Program Committee for the ACI Fall 2009 Convention will select the papers to be presented at the technical session. The authors of the selected abstracts will be invited to submit a full paper that will be peer reviewed for publication. Requirements: 1) Paper title; 2) author/speaker name(s), title, organization, address, telephone, fax, and e-mail; and 3) a one-page abstract. Deadline: Abstracts are due by June 15, 2009. Send to: Subhash Kulkarni at telephone: (504) 887-3100; e-mail: [email protected]; or Jesse Hemeter at telephone: (504) 593-5303; e-mail: [email protected].

ERRORS IN DESIGN AND CONSTRUCTION Meeting: Technical session on “Errors in the Design and Construction of Concrete Structures—Examples, Consequences, and Mitigation” at the ACI Spring 2010 Convention, March 21-25, 2010, Chicago, IL; sponsored by ACI Committee 348, Structural Safety, and cosponsored by ACI Committee 345, Concrete

Bridge Construction, Maintenance, and Repair. Solicited: Presentations/papers discussing errors in the design and construction of concrete structures are invited. Errors, whether human, material, or equipment related, could occur during the design process or construction phase of projects. The purpose of the session is to put forward some examples that identify where these types of errors occurred and show the consequences of such errors. This could be beneficial to engineers, educators, and contractors so they can mitigate these errors in the future. Requirements: 1) Presentation/ paper title; 2) author/speaker name(s), title, organization, mailing address, telephone, fax, and e-mail; and 3) an abstract of up to 300 words. Deadlines: Abstracts by June 30, 2009; final papers are due September 30, 2009. Send to: Mahmoud Maamouri, Computerized Structural Design SC, 8989 N. Port Washington Rd., Milwaukee, WI 53217; telephone: (414) 247-2843; fax: (414) 351-4617; e-mail: [email protected].

MICRO- AND MACROCRACKING Meeting: Technical session on “Effects of Micro- and Macrocracking on Durability” at the ACI Spring 2010 Convention, March 21-25, 2010, Chicago, IL. Solicited: ACI Committees 201, Durability of Concrete, and 224,

Cracking, are soliciting papers for a fullday session and a Special Publication on the topic of the effects of micro- and macrocracking on the durability of concrete structures. Examples of topics to be explored include the impact micro- and macrocracking can have on the long-term service life of a structure, investigative and analytical techniques used to assess the impact of these cracks on durability, and effective mitigation techniques used to improve durability. Requirements: 1) Presentation/ paper title; 2) author/speaker name(s), mailing address, telephone, fax, and e-mail; and 3) an abstract of 300 words. Papers must follow ACI publication guidelines and format. Please submit abstracts by e-mail. Deadlines: Abstracts by July 1, 2009; final papers are due December 1, 2009. Send to: Ralf Leistikow, Wiss, Janney, Elstner Assoc., Inc.; telephone: (770) 923-9822; e-mail: rleistikow@ wje.com.

NOTABLE CONCRETE IN NEW ORLEANS Publication: Compendium of notable concrete in New Orleans, LA, and vicinity for distribution at the ACI Fall 2009 Convention, November 8-12, 2009, New Orleans, LA; coordinated and compiled by ACI Committee 124, Concrete Aesthetics, and the ACI Louisiana Chapter. Document also will be stored and available as an electronic file on the ACI Committee 124 Web page and

may be available on the chapter Web site. Submitted images will be stored and available as electronic files on the ACI Web site and may be used in ACI educational and promotional materials. Solicited: Thumbnail image and brief description of notable concrete—cast-in-place, precast, posttensioned, masonry, tilt-up, etc.—in all types of uses: buildings, monuments, pavement, silos, bridges, crypts, furniture, retaining walls, utility poles, tanks, sculpture, culverts, plazas, and whatever else has caught your attention. Significance may be historical, aesthetic, functional, structural, construction-related, unusual use or application, or simply personal affection. Requirements: 1) Name and location of submission; 2) thumbnail image (photograph, drawing, or sketch) that is not copyrighted; 3) one- or two-sentence description that establishes significance; and 4) submitter’s name, title, organization, city and state, telephone, and e-mail. Location information should be sufficient to enable discovery by reader. Submit all information in electronic format (postcard-size image as JPEG or TIFF file, text in e-mail or as a .doc document). Deadline: Submissions by August 1, 2009. Send to: Michael J. Paul, Duffield Associates, 211 N. 13th St., Ste. 704, Philadelphia, PA, 19107; telephone: (215) 545-7295; e-mail: mpaul@ duffnet.com.

Submission guidelines: Calls for Papers We recommend that notices of calls for papers be submitted to Concrete International at least 9 months (or sooner) prior to the prospective sessions. This timetable generally allows publishing of the notification in three issues of the magazine. Please send meeting information, papers/presentations being solicited, abstract requirements and deadline, along with full contact information to: Keith A. Tosolt, Managing Editor, Concrete International, P.O. Box 9094, Farmington Hills, MI 48333-9094; fax: (248) 848-3150; e-mail: [email protected]. Visit www.callforpapers.concrete.org for more information.


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Next Time...

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To schedule your lab for CCRL inspection, and to arrange for performance testing, contact Jan Prowell at (301) 975-6704.

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Visit www.ACI Certification.org for: Descriptions of ACI Certification Programs — Includes program requirements and reference/ resource materials. Schedule of Upcoming/Testing Sessions — Search by program and/or state. Directory of Certified Individuals— Confirm an individual’s certification and date of expiration.

ACI’s New Fellows Twenty-eight members to be honored in San Antonio

t the upcoming ACI 2009 Spring Convention, ACI will recognize its newest group of members who have attained the rank of Fellow of the American Concrete Institute (FACI). The new Fellows will be introduced during the Opening Session and Awards Program on March 15. The spring convention is scheduled for March 15-19 at the Marriott Rivercenter, San Antonio, TX. As stated in the ACI Bylaws, a Fellow is an individual who has made “outstanding contributions to the production or use of concrete materials, products, and structures in the areas of education, research, development, design, construction, or management.” The Fellows Nomination Committee selects those to be considered for the award, and then forwards its recommendations to the Board of Direction for final action at its fall meeting. Nominations may come from the committee itself, from local chapters, from the International Committee, or by petition signed by at least five current ACI members. The ACI Board of Direction approved the nominations of this latest group of honorees at the ACI 2008 Fall Convention in St. Louis, MO. Including the new honorees, 699 members have attained the rank of FACI, first established by the Institute in 1973. ACI’s new Fellows are:

A

Peter H. Bischoff is a Professor in the Department of Civil Engineering, University of New Brunswick, Fredericton, NB, Canada, where he has contributed to teaching and research in the area of reinforced and prestressed concrete since 1992. Bischoff is a member of ACI Committees 224, Cracking; 360, Design of Slabs on Ground; 435, Deflection of Concrete Building Structures; 544, Fiber Reinforced Concrete; and Joint ACI-ASCE Committee 408, Development and Splicing

of Deformed Bars. He is a past member of ACI Committees 370, Short Duration Dynamic and Vibratory Load Effects; and 444, Experimental Analysis for Concrete Structures. He also served as Chapter Officer and Vice President of the ACI Atlantic Chapter. He recently received the Casimir Gzowski Medal from the Canadian Society for Civil Engineering (CSCE) for a paper related to development of a rational approach for computing deflection of reinforced concrete flexural members. His research interests include serviceability behavior of concrete structures, use of fiber-reinforced concrete in structural applications, soil-structure interaction related to ground supported slabs and footings, and impact behavior of concrete. He received his BASc in civil engineering from the University of British Columbia, Canada, in 1979; his MEng from McGill University, Canada, in 1983; his PhD from the University of London, UK, in 1988; and his DIC from Imperial College of Science and Technology, UK, in 1988. He is a licensed professional engineer in New Brunswick. Benoît Bissonnette is an Associate Professor in the Department of Civil Engineering, Laval University, Quebec City, QC, Canada, where he started his tenure in 1996. He has authored or co-authored over 100 technical papers and reports. He is a member of ACI Committees 223, Shrinkage-Compensating Concrete, and 364, Rehabilitation. He received the ACI Scholarship Award in 1991 and the ACI Quebec and Eastern Ontario Chapter Scholarship in 1993. He served as President of the ACI Quebec and Eastern Ontario Chapter in 2001-2002. As a member of the Research Center on Concrete Infrastructures (CRIB), his research interests include concrete repairs, creep and shrinkage, cracking, special Concrete international

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concretes, predictive modeling, instrumentation, and test methods. He is also a member of technical committees of the International Concrete Repair Institute (ICRI) and the Réunion Internationale des Laboratoires d’Essais et de Matériaux (RILEM). In 1999, he participated in the foundation of a North American task group devoted to the improvement of concrete repairs (CREEP); and in 2000, he co-founded the ICRI Quebec chapter. He received his BSc and PhD in civil engineering from Laval University, Quebec, QC, Canada, in 1990 and 1996, respectively. He is a licensed professional engineer in Quebec.

He is a member of ACI Committees 118, Use of Computers; 318-D, Flexure and Axial Loads: Beams, Slabs, and Columns; 435, Deflection of Concrete Building Structures; and Joint ACI-ASCE Committees 421, Design of Reinforced Concrete Slabs; 423, Prestressed Concrete; and 447, Finite Element Analysis of Reinforced Concrete Structures. His research interests include the modeling of concrete structures and automation in the AEC workflow. He received his BS and MS in civil engineering from the Massachusetts Institute of Technology in 1984 and 1985, respectively. He is a licensed professional engineer in Washington.

Allan P. Bommer is the Chief Design Engineer for Concrete Structures at Bentley Systems, Seattle, WA. He has been a leader in the development of concrete design software for 20 years.

Andrew J. Boyd is an Assistant Professor in the Department of Civil Engineering, McGill University, Montreal, QC, Canada, where he has been for the past 2 years. He is a member of ACI Committees 201, Durability of Concrete; 228, Nondestructive Testing of Concrete; 236, Material Science of Concrete; and 524, Plastering. He is also a member of task groups on the Incorporation of ACI Certification in University Engineering Curriculum and the Certification of Nondestructive Testing Technicians. He served on the Board of Directors of the ACI British Columbia Chapter and the ACI Florida First Coast Chapter. He is also a member of the American Society of Civil Engineers (ASCE) and ASTM International. Boyd’s research interests include the field of concrete materials, with an emphasis on material characterization, durability, nondestructive testing and evaluation, and the development of new testing techniques for concrete materials and products. He received his BScEng, MASc, and PhD in civil engineering from the University of New Brunswick, Fredericton, NB, Canada, in 1993; the University of Toronto, Toronto, ON, Canada, in 1995; and the University of British Columbia, Vancouver, BC, Canada, in 2001, respectively. He is a licensed professional engineer in New Brunswick.

NEW FELLOWS OF ACI As approved by the ACI Board of Direction at the ACI Fall 2008 Convention in St. Louis, MO, the 28 members being elevated to the rank of Fellow of the American Concrete Institute are: Peter H. Bischoff, Fredericton, NB, Canada Benoît Bissonnette, Quebec City, QC, Canada Allan P. Bommer, Seattle, WA Andrew J. Boyd, Montreal, QC, Canada Sergio F. Breña, Amherst, MA Vicki L. Brown, Chester, PA JoAnn P. Browning, Lawrence, KS Neeraj Buch, East Lansing, MI Oan Chul Choi, Seoul, Korea Norbert J. Delatte, Cleveland, OH Sofia Maria Carrato Diniz, Belo Horizonte, Brazil Alvin C. Ericson, Bonita Springs, FL Jorge L. Fuentes, San Juan, PR Jiann-Wen Woody Ju, Los Angeles, CA James M. LaFave, Urbana, IL Peter Marti, Zurich, Switzerland Richard J. McGrath, Ottawa, ON, Canada Barzin Mobasher, Tempe, AZ Kamran M. Nemati, Seattle, WA Karthikeyan H. Obla, Silver Spring, MD William D. Palmer Jr., Lyons, CO Andrea J. Schokker, Duluth, MN Jeffrey L. Smith, Frankfort, KY Douglas J. Sordyl, Farmington Hills, MI Pericles C. Stivaros, Jericho, NY Arezki Tagnit-Hamou, Sherbrooke, QC, Canada Mostapha A. Vand, Tehran, Iran Nur Yazdani, Arlington, TX

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Sergio F. Breña is an Associate Professor in the Department of Civil and Environmental Engineering, University of Massachusetts Amherst, MA, where he has been a member of the faculty since 2000. He is Secretary of ACI Committee 369, Seismic Repair and Rehabilitation, and is a member of ACI Committees 374, Performance-Based Seismic Design of Concrete Buildings; 440, Fiber-Reinforced Polymer Reinforcement; the ACI Publications Committee; and Joint ACI-ASCE Committee 445, Shear and Torsion. He is also a member of the American Society of Civil Engineers (ASCE) and the Precast/ Prestressed Concrete Institute (PCI). His research interests include the design and behavior of structural concrete elements, the use of fiber-reinforced polymer composites to rehabilitate existing structures, and field performance of existing bridges.

Bischoff

Bissonnette

Bommer

He received his BS in civil engineering from Universidad Iberoamericana, Mexico City, Mexico, in 1989, and his MS and PhD in civil engineering from the University of Texas at Austin, Austin, TX, in 1990 and 2000, respectively. Vicki L. Brown is an Associate Professor and Chairman of the Department of Civil Engineering, Widener University, Chester, PA. She joined the Widener Faculty in 1981, and has served as Chairman of Civil Engineering for the past 8 years. She is a Past Chair of ACI Committee E804, Education Awards Nomination Committee; serves as Co-Chair of Subcommittee 440G, Student Education; coordinates the ACI FRP Composites Competition; and is a member of ACI Committees E801, Student Activities, and 440, Fiber Reinforced Polymer Reinforcement. She is also a member of the Competition Committee for the ACI Eastern Pennsylvania and Delaware (EPDACI) Chapter’s Student Concrete Beam Competition, and has hosted the annual competition at Widener since 2001. She is a past member of the ACI Chapter Activities Committee and the ACI Educational Activities Committee. She has served on the Board of Directors of the EPDACI Chapter and as Student Activities Chair for the ACI 2001 Convention in Philadelphia, PA, and was a member of the EPDACI Chapter’s Planning Committee. She is also a member of the American Society of Civil Engineers (ASCE). Her research interests include the use of fiber-reinforced polymers as reinforcement for structural concrete. Brown received her BS in civil engineering technology from the University of Pittsburgh, Johnstown, PA, in 1976, and her PhD in civil engineering from the University of Delaware, Newark, DE, in 1988. She is a licensed professional engineer in Pennsylvania. JoAnn P. Browning is an Associate Professor in the Department of Civil, Environmental, and Architectural Engineering, University of Kansas, Lawrence, KS. She is Chair of ACI Committee 314, Simplified Design of Concrete Buildings, and is a member of ACI Committees 318-D, Flexure and Axial Loads: Beams, Slabs, and Columns;

Boyd

Breña

341, Earthquake-Resistant Concrete Bridges; 374, Performance-Based Seismic Design of Concrete Buildings; the ACI Publications Committee; and Joint ACI-ASCE Committee 408, Development and Splicing of Deformed Bars. She serves on the Board of Directors of the ACI Kansas Chapter. She is a member of the American Society of Civil Engineers (ASCE). Her research interests include seismic performance of concrete building and bridge systems and durability of concrete bridge decks. Browning received her BS and MS in civil engineering from the University of Kentucky, Lexington, KY, in 1994 and 1995, respectively, and her PhD in civil engineering from Purdue University, West Lafayette, IN, in 1998. She is a licensed professional engineer in Kansas. Neeraj Buch is a Professor and Director of the Pavement Research Center of Excellence, Department of Civil and Environmental Engineering, Michigan State University (MSU), East Lansing, MI. He is Chair of ACI Committee 325, Concrete Pavements, and is a member of ACI Committees E802, Teaching Methods and Educational Materials, and 236, Material Science of Concrete. He is Past Chair of ACI Committee 549, Thin Reinforced Cementitious Products and Ferrocement. He is an Instructor for the Portland Cement Concrete (PCC) Overlays: State of The Technology Workshops, sponsored by the Federal Highway Administration (FHWA) and ACI. He is also a member of the American Society of Civil Engineers (ASCE) and served as the Faculty Advisor for the ASCE student chapter at MSU for 6 years. He has authored or co-authored over 75 technical articles and research reports. In addition, he has worked on numerous projects funded by state and federal highway agencies. Buch has performed research on characterization of portland cement concrete mixtures and their impact on pavement design and performance, pavement response and performance modeling, and pavement preservation. His research interests include the investigation of design and construction factors on the response and performance of new flexible and rigid pavements Concrete international

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Brown

Browning

Buch

Choi

Delatte

(LTPP program), the effectiveness of precast panels as Military Academy and the University Alabama, a rapid repair alternative, and the impact of dowel Birmingham, AL. He has authored or co-authored misalignment on the performance of concrete pavements. over 50 technical papers and reports, as well as the He received his MS from the University of Michigan, books Concrete Pavement Design, Construction, and Ann Arbor, MI, in 1988, and his PhD from Texas A&M Performan ce (2007) and Beyond Failure: Forensic Case University, College Station, TX, in 1995. Studies for Civil Engineers (2008). He is Chair of ACI Committee E803, Faculty Network Oan Chul Choi is a Professor of architectural Coordinating Committee, and is Past Chair of ACI engineering at Soongsil University, Seoul, Korea. Prior Committee 325, Concrete Pavements. He is a member of to this, he taught courses on reinforced concrete for ACI Committees 327, Roller Compacted Concrete 3 years at Ulsan University and worked for 4 years at Pavements; 330, Concrete Parking Lots and Site Paving; Hyundai Construction Company. 522, Pervious Concretes; E802, Teaching Methods and He is a member of ACI Committees 335, Composite Educational Materials; and the Advisory Committee for and Hybrid Structures; 440, Fiber Reinforced Polymer Young Members. He is also a member of the American Reinforcement; and Joint ACI-ASCE Committee 408, Society of Civil Engineers (ASCE). He is the Editor of the Development and Splicing of Deformed Bars. As Vice ASCE Journal of Professional Issues in Engineering President of the Korea Concrete Institute (KCI), he has Education and Practice, and Chair of the ASCE Technical made efforts to enhance the relationship between ACI Council on Forensic Engineering. He received the ACI and KCI. He is a past member of the Scientific Committee Walter P. Moore Jr. Faculty Achievement Award in 2003 of the ACI/KCI International Conference held in Seoul in and the ACI Delmar L. Bloem Distinguished Service 2000, and was the Organizing Chair of the ACI-KCI Joint Award in 2008. Seminar, Korea, in 2002. His research interests include concrete pavements and He received the ACI Structural Research Award in overlays, roller-compacted concrete, pervious concrete, 1996. He also received the Architectural Institute of Korea high-performance/high-strength concrete, and the use of (AIK) Research Award in 2001 and the KCI Distinguished failure case studies in engineering education. Achievement Award in 2003. He has authored or He received his BS in civil engineering from The co-authored over 100 technical papers and reports. Citadel, Charleston, SC, in 1984; his SM (master’s degree) His research interests include bond of reinforcement in civil engineering from the Massachusetts Institute of to concrete, composite and hybrid structures, fiberTechnology, Cambridge, MA, in 1986; and his PhD in civil reinforced polymer reinforcement, and corrosion of engineering from the University of Texas at Austin, reinforcing steel in concrete structures. Austin, TX, in 1996. He is a licensed professional engineer Choi received his BS and MS in architectural engineering in Ohio, Alabama, and Virginia. from Seoul National University in 1977 and 1981, respectively. He received his PhD in civil engineering from the University Sofia Maria Carrato Diniz is an Associate of Kansas, Lawrence, KS, in 1990. Professor, Department of Structural Engineering, Federal University of Minas Gerais, Belo Horizonte, Norbert J. Delatte is a Professor in the Department Brazil. She is also a researcher with the Conselho of Civil and Environmental Engineering, Fenn College Nacional de Desenvolvimento Científico e Tecnológico, of Engineering at Cleveland State University (CSU), CNPq (Brazilian Science Foundation). Cleveland, OH, and has been on the faculty since 2003. She is Chair of ACI Committee 348, Structural Safety, He previously served on the faculty of the United States and is a member of the ACI Marketing Committee. She has

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MARCH 2009


Diniz

Ericson

Fuentes

also served as a member on the Chester Paul Siess Award for Excellence in Structural Research Committee, Committee on Awards for Papers (CAP), and ACI Committee 318-C, Safety, Serviceability, and Analysis. She is a member of the American Society of Civil Engineers (ASCE) and Past Chair of the Joint SEI (Structural Engineering Institute)-ASCE Committee, Safety of Buildings, and is a member of the Joint SEI-ASCE Technical Administrative Committee (TAC), Structural Safety and Reliability. She has authored or co-authored over 70 technical papers and served as a reviewer for the ACI Materials Journal and the ACI Structural Journal. Her research interests include high-performance materials, including the probabilistic modeling of loads and resistances and attendant codification issues. She received her BS in civil engineering and MS in nuclear engineering from the Federal University of Minas Gerais in 1979 and 1988, respectively, and her PhD in civil engineering from the University of Colorado at Boulder, Boulder, CO, in 1994. Alvin C. Ericson is an Independent Technical Consultant from Bonita Springs, FL, specializing in precast concrete construction systems and connections. He is Chair of the Emulative Detailing Task Group of Joint ACI-ASCE Committee 550, Precast Concrete Structures, and is a member of ACI Committees 370, Short Duration Dynamic and Vibratory Load Effects; 551, Tilt-Up Concrete Construction; and Joint ACI-ASCE Committee 408, Development and Splicing of Deformed Bars. He is a past member of ACI Committee 439, Steel Reinforcement. He is Past President of the ACI New England Chapter. He is a Fellow of the Precast/Prestressed Concrete Institute (PCI), former Chair of PCI’s Student Education Committee, and Co-Chair of the recently formed Blast Resistance and Structural Integrity Committee. He served on the PCI Board of Directors from 2000 to 2003. He is a Past Chair of the Structural Group of the Boston Society of Civil Engineers Section of the American Society of Civil Engineers (ASCE) and Past President of

Ju

LaFave

the Boston Chapter of the Massachusetts Society of Professional Engineers. He received his BS in art and design from the Massachusetts Institute of Technology, Cambridge, MA, in 1977 and his MBA from Northeastern University, Boston, MA, in 1985. Jorge L. Fuentes is a licensed professional engineer who has worked in the pile foundation, deep excavations, and heavy and marine construction fields in and around Puerto Rico since 1971. He has been instrumental in promoting the use of the sectional precast concrete pile known as the “Fuentes Concrete Pile,” (patented worldwide by his father Gabriel Fuentes Jr., PE), making it a viable and sound foundation solution in hundreds of projects. To date, Fuentes has been directly involved in the manufacture and installation of over 20 million feet of precast concrete piles. Fuentes served as Chair of ACI Committee 543, Concrete Piles, from 1993 to 2000. He also is a member of ASTM International and other organizations that include nonprofit and publicly traded companies. Fuentes received a BS in mechanical engineering from the University of Puerto Rico, Mayaguez, PR, in 1971. Jiann-Wen Woody Ju is a Professor in the Department of Civil and Environmental Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA. He has been a professor at UCLA since 1993. He is a member of ACI Committees 201, Durability of Concrete; 228, Nondestructive Testing of Concrete; and Joint ACI-ASCE Committee 446, Fracture Mechanics of Concrete, which he also chaired from 2004 to 2008. Ju has authored or co-authored over 160 technical papers in scholarly journals and conference proceedings, and published eight books. His research interests include micromechanics of materials, micromechanical damage mechanics, continuum damage mechanics, fracture mechanics, failure mechanics, materials modeling, plasticity and viscoplasticity, concrete behavior and degradation, Concrete international

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Marti

McGrath

Mobasher

durability of concrete and composites, fiber-reinforced cementitious composites, nondestructive and destructive testing of concrete, advanced composite materials, biomechanics, nano-mechanics, nano-materials, nonlinear computational mechanics, finite element methods, geomechanics, and coupled thermo-hygro-mechanical modeling of materials. Ju is a Fellow of the American Society of Civil Engineers (ASCE) and received the 1997 ASCE Walter L. Huber Civil Engineering Research Prize. He also received the 1991 Presidential Young Investigator Award from the National Science Foundation, the 1991 Alfred Rheinstein Faculty Award from Princeton University, and the 2008 Publication Award of Merit from the Structural Engineers Association of Illinois. He received his BS in civil engineering from National Taiwan University, Taipei, Taiwan, in 1980, and his MS and PhD in civil engineering from the University of California at Berkeley, Berkeley, CA, in 1983 and 1986, respectively. He is a licensed professional engineer in California and Arizona. James M. LaFave is an Associate Professor in the Department of Civil and Environmental Engineering, the University of Illinois at Urbana-Champaign, Urbana, IL, where he teaches undergraduate and graduate courses in structural design. He is Chair of Joint ACI-ASCE Committee 352, Joints and Connections in Monolithic Concrete Structures, and is a member of ACI Committee 374, PerformanceBased Seismic Design of Concrete Buildings; Joint ACI-ASCE Committee 408, Development and Splicing of Deformed Bars; and a subcommittee member of Joint ACI-ASCE-TMS Committee 530, Masonry Standards Joint Committee. He is a past member of several other ACI committees. He is also a member of the Earthquake Engineering Research Institute (EERI). His research interests include the experimental behavior and analytical modeling of structural connections and joints for applications such as performance and assessment of reinforced concrete

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MARCH 2009


Nemati

Obla

buildings and bridge structures subjected to earthquakes, seismic and wind performance of light-frame construction with brick masonry veneer, evaluation of sign truss structures, innovative composite structural framing systems, and concrete durability. He received the Illinois ASCE Student Chapter Outstanding Instructor Award in 2002 and 2005, the Illinois College of Engineering Xerox Award for Faculty Research in 2005, the ASTM International Alan H. Yorkdale Memorial Award in 2006, and the Outstanding TMS Journal Paper Award from The Masonry Society in 2007. He received his BS and MS in civil engineering from the University of Illinois and his PhD in civil (structural) engineering from the University of Michigan, Ann Arbor, MI, in 1986, 1987, and 1997, respectively. He is a licensed professional engineer. Peter Marti is a Professor of structural engineering and Head of the Department of Civil, Environmental and Geomatic Engineering, at the Swiss Federal Institute of Technology (ETH), Zurich, Switzerland. Prior to this, he was an Associate Professor of structural engineering at the University of Toronto, Toronto, ON, Canada; an Executive Vice President of VSL International Ltd., Berne, Switzerland; and Chief Technical Officer of the VSL Group. He is Past Chair of Joint ACI-ASCE Committee 445, Shear and Torsion, and a past member of ACI Committee 318-E, Shear and Torsion; and Joint ACI-ASCE Committees 421, Design of Reinforced Concrete Slabs; and 423, Prestressed Concrete. He is a Fellow of the American Society of Civil Engineers (ASCE) and a member of the Precast/Prestressed Concrete Institute (PCI). His research interests include the behavior, modeling, and design of structural concrete and masonry. He received his diploma in civil engineering in 1973 and his Dr. sc. techn. degree in 1980, both from ETH. He is a licensed professional engineer in Ontario. Richard J. McGrath has worked for the Cement Association of Canada (CAC) for the past 27 years and

currently serves as their Director, Codes and Standards and Engineered Structures. He is the Editor of the last three editions of the CAC Concrete Design Handbook. He is a member of ACI Committee 355, Anchorage to Concrete, and Joint ACI-TMS Committee 216, Fire Resistance and Fire Protection of Structures. He is Chairman of the Canadian Standards Association (CSA) Strategic Standing Committee on Concrete and Related Products, and Vice-Chairman of CSA Committee A23.3, Design of Concrete Structures Standard, as well as a member of numerous other CSA committees. He is a member of the Precast/Prestressed Concrete Institute (PCI) and a member of the National Building Code of Canada Part 3 Standing Committee on Fire Safety and Part 4 Standing Committee on Structural Design. His research interests include the fire resistance of concrete structures and structural masonry performance. He received his Bachelor of Engineering degree from Carleton University, Ottawa, ON, Canada, in 1978 and is a licensed professional engineer in Ontario. Barzin Mobasher is a Professor in the Department of Civil and Environmental Engineering, Arizona State University, Tempe, AZ. He has been involved in research and education in the cement and concrete area for the past 25 years and was the recipient of an ACI Scholarship Award in 1984. He is a Past Secretary and member of Joint ACI-ASCE Committee 446, Fracture Mechanics of Concrete, and a member of ACI Committees 544, Fiber Reinforced Concrete, and 549, Thin Reinforced Cementitious Products and Ferrocement. He is a member of the American Society of Civil Engineers (ASCE) and has published over 100 peer-reviewed publications in various areas dealing with mechanics and durability aspects of concrete technology.

His research interests include sustainable-based design; blended cements; design for durability; modeling; testing; specification development; fiber-reinforced concrete materials with a focus on the development of high-performance fiber and fabric-

reinforced cement composites; and testing, analysis, and modeling of mechanical properties of concrete materials. He received his BS in 1983 from University of Wisconsin-Platteville, WI; his MS in 1985 from Northeastern



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Palmer

Schokker

Smith

University, MA; and his PhD in 1990 from Northwestern University, IL. Kamran M. Nemati is an Associate Professor in the Departments of Construction Management and Civil and Environmental Engineering at the University of Washington, Seattle, WA. He was an invited faculty member at the University of Tokyo and the Tokyo Institute of Technology in Japan from 2005 to 2007. He is a member of ACI Committees 224, Cracking; 231, Properties of Concrete at Early Ages; 236, Material Science of Concrete; 325, Concrete Pavements; and Joint ACI-ASCE Committee 446, Fracture Mechanics of Concrete. He also served as a past member of the Board of Directors of the ACI Washington Chapter. He is a Fellow of the American Society of Civil Engineers (ASCE) and a member of the International Association for Fracture Mechanics of Concrete and Concrete Structures (FraMCoS). He has authored or co-authored over 50 technical papers and reports. His research interests include the application of innovative experimental techniques to investigate the fracture behavior of concrete, the relationship between compressive strength and modulus of elasticity of highstrength concrete, and accelerated pavement construction with portland cement concrete. He received his PhD in civil engineering from the University of California at Berkeley, Berkeley, CA, in 1994, where he was also a post-doctoral research fellow until August 1998. He received his MS in civil engineering (environmental engineering) in 1982, his MEng in civil engineering (geotechnical and construction engineering) in 1985, and his Master of City and Regional Planning (urban transportation planning) in 1999, all from the University of California at Berkeley. He is a licensed professional engineer in California, Washington, and New York. Karthikeyan H. Obla is the Managing Director, Research and Materials Engineering at the National Ready Mixed Concrete Association (NRMCA), Silver Spring, MD.

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MARCH 2009


Sordyl

Stivaros

Prior to joining NRMCA in 2003, he worked as a Technical Manager at Boral Material Technologies for 6 years. He is Secretary of ACI Committee 232, Fly Ash and Natural Pozzolans in Concrete, and is a member of ACI Committees 201, Durability of Concrete; 211, Proportioning Concrete Mixtures; 365, Service Life Prediction; 555, Concrete with Recycled Materials; and C601-B, Certified Quality Technical Manager. He is a Past Secretary of ACI Committee 236, Material Science of Concrete, and a past member of ACI Committees 222, Corrosion of Metals in Concrete; 350, Environmental Engineering Concrete Structures; 544, Fiber Reinforced Concrete; and the Chapter Activities Committee. He is a Past Vice-President and Past President of the ACI San Antonio Chapter. Obla is an active member of various ASTM International and Transportation Research Board (TRB) technical committees and has authored or co-authored over 50 technical papers and reports. Obla’s research interests include concrete materials technology, specifications, test methods, and the use of recycled materials. He received his bachelor’s degree in technology in civil engineering from the Institute of Technology, Banaras Hindu University, Varanasi, India, in 1991, and his MS and PhD in civil engineering from the University of Michigan, Ann Arbor, MI, in 1993 and 1997, respectively. He is a licensed professional engineer in Michigan. William D. Palmer Jr. is President of Complete Construction Consultants, where he develops technical and educational resources for the construction industry and consults on concrete, masonry, and public works. He is Past Chair of ACI Committee E703, Concrete Construction Practices, where he was named Educational Committee Member of the Year in 2006. He is a member of ACI Committees 306, Cold Weather Concreting; C601-D, Decorative Concrete Finisher; C640, Craftsman Certification; and the Certification Programs Committee. He is a member of the American Society of Civil Engineers (ASCE) and ASTM International. Palmer has contributed to concrete and

masonry education, first as an Engineering Editor for Concrete International , then as ACI’s Director of Education from 1989 to 1994. In 1995, he became Executive Director of The Masonry Society and was Editor in Chief of Concrete Construction magazine for 7 years. He was also Executive Vice President of the American Society of Concrete Contractors (ASCC). He received his bachelor’s degree in civil engineering from the University of Colorado at Denver, Denver, CO, in 1980 and his master’s degree from the University of Tagnit-Hamou Vand Yazdani Iowa, Iowa City, IA, in 1982. He is a licensed professional engineer in Michigan and Colorado. He is Secretary of ACI Committee 342, Evaluation of Concrete Bridges and Bridge Elements, and is a member Andrea J. Schokker is a Professor and the Head of of ACI Committees 343, Concrete Bridge Design; 345, Civil Engineering at the University of Minnesota Duluth. Concrete Bridge Construction, Maintenance, and Repair; Prior to this, she was on the faculty at Pennsylvania State and 364, Rehabilitation. He is also a member of the University for 9 years. American Society of Civil Engineers (ASCE), the Precast/ She is a member of the ACI Board of Direction and Prestressed Concrete Institute (PCI), the National Society Chair of Joint ACI-ASCE Committee 423, Prestressed of Professional Engineers (NSPE), and the National Concrete, and the Advisory Committee for Young Members. Association of Corrosion Engineers (NACE). She is a Past Chair and member of the ACI Chapter His research interests include concrete bridge Activities Committee and ACI Committee E803, Faculty evaluation, bridge design, concrete bridge rehabilitation, Network Coordinating Committee. She is also a member and corrosion. of ACI Committees 130, Sustainability of Concrete; 222, He received his Bachelor of Environmental Design Corrosion of Metals in Concrete; 224, Cracking; 318-G, (Architecture) from Miami University, Oxford, OH, in Precast and Prestressed Concrete; the Educational 1975; his BSCE from the University of Toledo, Toledo, OH, Activities Committee; and the Membership Committee. in 1979; and his MSCE from the University of Kansas, She is a past member of the International Committee and Lawrence, KS, in 1995. He is a licensed professional the Scholarship Committee. She is also a member of the engineer in Ohio and Virginia. American Society of Civil Engineers (ASCE) and the Precast/Prestressed Concrete Institute (PCI). Douglas J. Sordyl is the Managing Director of the She received the ACI Young Member Award for Strategic Development Council and the Managing Director Professional Achievement in 2004 and was named ACI of Marketing, Sales & Industry Relations for the American Education Committee Member of the Year in 2003. Concrete Institute, Farmington Hills, MI. For 30 years Schokker’s research interests include design- and before joining ACI, Sordyl worked in various positions material-related improvements in prestressed concrete in structural engineering, project management, and (with an emphasis in post-tensioning applications) and company operations for Giffels Associates and ARCADIS, the sustainability of concrete structures. Southfield, MI. He is also the Staff Liaison to ACI’s Board She received her BS in 1993 and her MS in 1994 from Advisory Committee on Sustainable Development and the Washington University, St. Louis, MO, and her PhD in ACI Foundation. 1999 from the University of Texas at Austin, Austin, TX. He is a past member of ACI Committees 211, Proportioning Concrete Mixtures; 301, Specifications for Concrete; and 302, Jeffrey L. Smith is the Structures Engineer for the Construction of Concrete Floors. Federal Highway Administration in the Kentucky Division He was Co-Chair of the ACI Spring 2002 Convention in Office, Frankfort, KY. During his 29 years of service, he Detroit, MI, and a Board member, Past President, and has held positions in the Federal Lands Highway Division Secretary of the ACI Greater Michigan Chapter. He received Bridge Design Office, the Division Offices in Hawaii and the chapter’s Arthur Y. Moy Memorial Award in 2008. Kansas, and the Resource Center Structures Technical Sordyl is a past charter member and Past President of Services Team. the Structural Engineering Association of Michigan; a past He has authored or co-authored several reports and Board Member and Treasurer for the USGBC Detroit developed training courses related to concrete bridge Regional Chapter; and a member of the American Society design and bridge rehabilitation courses. of Civil Engineers (ASCE), the American Institute of Steel Concrete international

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Construction (AISC), and the Engineering Society of Detroit (ESD). Sordyl is also an ex-officio Board member of the Tilt-Up Concrete Association (TCA). Sordyl received his bachelor’s degree in civil engineering in 1973 and his master’s degree in engineering in 1976 from the University of Detroit, Detroit, MI, with emphasis in both structural and environmental/urban planning. He is a licensed professional engineer in Michigan and California. Pericles C. Stivaros is a Principal with Feld, Kaminetzky & Cohen, P.C., Consulting Engineers, Jericho, NY. He is in charge of the testing department of the firm, and is responsible for developing testing and monitoring programs for distressed structures and concrete structures in particular. He is also an Adjunct Professor of structural engineering and has authored several publications on formwork and shoring/reshoring construction operations and concrete testing and evaluation. He is Chair of ACI Committee 347, Formwork for Concrete, and is a member of ACI Committees 350, Environmental Engineering Concrete Structures; 362, Parking Structures; and the ACI TAC Tolerances Coordinating Committee. He presents seminars on Troubleshooting Concrete Forming and Shoring for ACI and is a member of the American Society of Civil Engineers (ASCE). His research interests include structural design and analysis of building systems, failure investigations, structural testing and distress analysis, structural evaluation and rehabilitation of buildings and other structures, and formwork and shoring/reshoring design. He received his degree in civil engineering from Higher Technical Institute (HTI), Cyprus, 1981, and his MS and PhD in civil engineering from West Virginia University, Morgantown, WV, in 1984 and 1988, respectively. He is a licensed professional engineer in New York, Connecticut, and Tennessee. Arezki Tagnit-Hamou is a Full Professor in the Department of Civil Engineering at the Université de Sherbrooke, Sherbrooke, QC, Canada. He is a member of ACI Committees 130, Sustainability of Concrete; 555, Concrete with Recycled Materials; the ACI Board Advisory Committee on Sustainable Development; and the Strategic Development Council (SDC). He is also a member of ASTM International. His research interests include physico-chemistry, microstructure and durability, supplementary cementitious materials, and sustainable development. Tagnit-Hamou received his undergraduate degree in chemical engineering from the Institut National des Hydrocarbures et de la Chimie (INHC), Boumerdes, Algeria, in 1980 and his doctoral degree in silicate chemistry and technology from the University of Veszprém, Hungary, in 1989.

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Mostapha A. Vand is the Director and CEO of the Concrete Research and Educational Center of Iran, Dean of Moassesseh Amoozesheh Alveh Beton, and co-founder of Vand Construction Chemicals Company. He is Chair of the International Roundtable Steering Committee for the 2009 roundtable in Cairo, Egypt, and is a member of the ACI International Committee; the ACI International Certification Committee; and ACI Committees C660, Shotcrete Nozzleman Certification; and E803, Faculty Network Coordinating Committee. He has been the ACI Iran Chapter Secretary since 1994 and was the recipient of the Chapter Activities Award in 2008. He is also a member of the American Society of Civil Engineers (ASCE). He has authored and co-authored more than 20 technical papers and reports. His research interests include self-consolidating concrete and the use of nano materials in high-performance/highdurability concrete. Vand received his BS and MS in civil engineering from the University of Missouri, Rolla, MO, in 1978 and 1980, respectively. Nur Yazdani is the Chairman and a Professor in the Department of Civil Engineering at the University of Texas at Arlington, Arlington, TX, where he also heads the Disaster Mitigation group. Prior to that, he was a faculty member at the Florida A&M University-Florida State University College of Engineering. Yazdani is the Chair of Joint ACI-ASCE Committee 343, Concrete Bridge Design, and is a member of ACI Committees 357, Offshore and Marine Concrete Structures, and 544, Fiber Reinforced Concrete. He is a past member of ACI Committees 123, Research and Current Development, and 423, Prestressed Concrete. He has authored or co-authored over 75 technical papers and research reports. Yazdani is a Fellow of the American Society of Civil Engineers (ASCE) and a member of the Precast/ Prestressed Concrete Institute (PCI). He received the Daniel P. Jenny PCI Fellowship in 1995 and the Davis Productivity Award from the State of Florida in 2005. He is on the Editorial Board of the ASCE Journal of Bridge Engineering . He has served on the review panels of the National Cooperative Highway Research Institute (NCHRP). Yazdani’s research interests include concrete bridge design and rehabilitation, fiber-reinforced concrete, concrete properties for bridge applications, and disaster mitigation of concrete structures. He received his BS in civil engineering from the University of Engineering & Technology, Dhaka, Bangladesh, in 1977; his MS in civil engineering from the University of Oklahoma, Norman, OK, in 1981; and his PhD from the University of Maryland, College Park, MD, in 1984. He is a licensed professional engineer in Texas.


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Sustainability through Strength Integrating post-tensioned lateral systems and slag cement concrete for a model of environmental architecture

BY MARK STEVENSON AND LEO PANIAN

S

ituated in downtown Berkeley, CA, within 0.6 mile (1 km) of the Hayward Fault, the new David Brower Center (Fig. 1) will provide offices and meeting space for environmental advocacy and nonprofit groups. The project, named after one of the preeminent environmental ists of the twentieth century, incorporates many features of sustainable design in the structural, mechanical, electrical, plumbing, and lighting systems and is expected to be LEED® Platinum certified by the U.S. Green Building Council. To protect the building against a highly likely major earthquake, the structure integrates a unique combination of post-tensioned concrete walls and frames that make efficient use of construction materials and will improve performance and limit damage. The defining feature of this system is its unique self-centering behavior that virtually eliminates permanent post-earthquake deformations. The hybrid system combines the elasticity of highstrength, unbonded tendons with the energy dissipation capacity of mild steel reinforcement to control the inelastic response of the structure. Specialized concrete mixtures, with large volumes of portland cement replaced with slag cement, were also integrated into the design to reduce the embodied energy and carbon footprint of the structure.

PROJECT DESCRIPTION The project is a combination of the four separate elements shown in Fig. 2: the four-story David Brower Center containing office space and a conference center, a multi-unit residential structure, ground floor retail space, and an underground parking garage. This article is focused on the David Brower Center.

With its distinctive elongated bullet shape, the Brower Center forms the northern boundary of the complex. With plan dimensions of approximately 62 x 196 ft (19 x 60 m), the Brower Center comprises roughly 50,000 ft2 (4650 m2 ) of the 225,000 ft2 (20,900 m2 ) complex. The construction cost of the entire project is about $50 million, and the cost of the Brower Center alone is estimated to be around $15.3 million. Floors consist of post-tensioned concrete flat slabs supported by uniformly arrayed columns. The perimeter columns are architecturally exposed. The seismic forceresisting system shown in Fig. 2 is a dual system of two centrally located, C-shaped, vertically post-tensioned core walls acting in conjunction with transverse posttensioned moment frames at the ends of the building. The entire structure is supported by a mat foundation. For both cost and environmental reasons, concrete was the material of choice for the structural system. The thermal mass is a key factor in reducing operational energy usage, and the slabs were integral to the installation and functioning of the radiant heating and cooling systems. The mechanical systems were run under a raised-floor system rather than hanging from the bottom of the slab. This allowed the slab soffits to remain exposed as a finished ceiling and allowed the hydronic tubes to be located at the bottom of the slabs, which simplified installation (Fig. 3). Other nonstructural strategies to minimize energy and water use included operable windows to allow natural ventilation, a basement cistern system to store rainwater runoff from the roofs and plazas for landscape irrigation, rooftop-mounted solar water heaters, and a 60 kW photovoltaic trellis crowning the Brower Center roof. Concrete international

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Fig. 1: Design and construction of the David Brower Center in Berkeley, CA, exemplified the missions of the environmental advocacy and nonprofit groups that will lease its office and meeting space

SEISMICITY AND SUSTAINABILITY The site is near a major fault system that is likely to produce a 7.0 or greater magnitude earthquake within the service life of the structure. A typical code-compliant building would be considered well-performing if it remained standing and allowed safe evacuation of the inhabitants after a major seismic event, even though residual drift and widespread damage to nonstructural components may render it unfit for continued use. In such buildings, permanent offsets can interfere with the functioning of doors, windows, elevator shafts, and other nonstructural components to such an extent that repairs are not economically feasible. In this setting, a major aspect of sustainable construction is continued functionality of the structure after the occurrence of a large earthquake. In other words, protection of the investment in energy and materials is a key “green” construction goal.

POST-TENSIONED CONCRETE SEISMIC SYSTEMS To best meet the cost and environmental goals for the project, the seismic force-resisting system incorporates post-tensioned cast-inplace concrete structural walls and

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post-tensioned moment-resisting frames that are seamlessly integrated with the building architecture. The flexural behavior of a posttensioned structural system is ideal for this application. The mild steel reinforcing bars yield to dissipate energy during a seismic event, while the unbonded tendons remain elastic to provide a positive restoring force that centers the structure following the event.1,2 The elastic restoring component is proportioned to be somewhat larger than the yielding component, which means that slightly more than half the total resistance is derived from posttensioning and contributes to the recentering effect. Key aspects of the design approach include:  Basic strength design to meet seismic design criteria as defined in ASCE 73 and ACI 3184 for special reinforced concrete walls and moment-resisting frames;  Structural walls proportioned so that the overall flexural strength attributable to post-tensioning alone is more than 55% of the total flexural strength;  Walls and frame elements designed with sufficient concrete area and strength to minimize crushing strains and maintain stable

compression zones at ultimate response; and  The use of capacity design principles for shear design. Properly proportioned, the system provides improved ductility and is less prone to physical damage during earthquake shaking. Moreover, the post-tensioning provides significant strength enhancement, substantially reducing conventional reinforcement in flexural members and resulting in more compact dimensions and improved constructibility. To predict forces in critical elements, eliminate nonductile failure modes, and ensure a stable flexural mechanism, nonlinear response history analyses were used in conjunction with capacity design principles.5,6 Interstory drifts under the design basis earthquake were kept well below the maximum prescribed by code to limit potential damage. Residual drifts and permanent deformations turned out to be negligible. Strains in the unbonded post-tensioning strands were limited to the elastic range, while the reinforcement was anticipated to experience significant yielding. A critical aspect of seismic detailing for structural concrete is confinement. Section ductility and good hysteretic behavior require that core concrete retain its integrity under high compressive strains and repeated load reversals. This becomes even more critical in post-tensioned seismic-resisting systems, where the added imposed compressive forces push concrete close to its ultimate crushing strain. Figures 4 and 5 show typical reinforcing details at critical regions of the walls and frames, respectively. Given the large No. 14 (No. 43) vertical flexural bars at the bases of the structural walls and No. 11 (No. 36) bars at the hinge regions combined with the functional need to minimize overall core dimensions, traditional hooked bars and crossties were not practical in the first two stories of

(a)

(b)

(c)

Fig. 2: Models of the David Brower Center: (a) the project included spaces for a multi-unit residential portion (upper left), with retail space below, office and conference space (upper right), and below-grade parking (basement); (b) overall structure of the office center; and (c) the lateral force-resisting system of the office center, consisting of vertically post-tensioned structural walls and post-tensioned frames

the cores. Headed bars were used at the most congested sections where anchorage of longitudinal or transverse reinforcement was critical. Their compact shape allowed them to be closely spaced while effectively engaging the horizontal and vertical bars. Confinement above the third floor was through the use of traditional hooked crossties. The post-tensioning tendons used in the walls and frames consist of bundles of 0.6 in. (15 mm) diameter, individually sheathed and greased strands in corrugated metal ducts. This approach allowed the ducts to be cast in place and the strands to be installed after the concrete was placed. Tendons typically contained 11 to 17 strands and terminated in multi-strand anchorage devices.

CONCRETE AND CARBON FOOTPRINT The project design goals emphasized efficiency in resource use, reduced embodied energy, and reduced life-cycle cost. Minimizing the amount of portland cement used in the concrete—typically a major component of embodied energy and carbon footprint for a concrete structure—was a key aspect of attaining this goal. The carbon footprint was minimized by using slag cement to replace large portions of the portland cement in the concrete. This saved an estimated 5000 tons (4500 tonnes) of CO2 emissions for the project. Low-impact mixtures were used throughout the project, with typical portland cement replacement values of 50% for slabs, columns, and walls, and 70% for the mat foundation. The mixtures used for the Brower Center typically had portland cement contents of 200 to 400 lb/yd3 (120 to 240 kg/m3 ). This is very low by traditional standards, as commonly available 3000 psi (21 MPa) concrete can have a portland cement content around 500 to 600 lb/yd3 (300 to 360 kg/m3 ), and typical shotcrete mixtures can contain up to 850 lb/yd3 (500 kg/m3 ).

Fig. 3: Although much of the mechanical and electrical systems were located under a raised floor (instead of hanging from the ceiling), the floor slabs contained lighting conduit and tubing for the hydronic heating and cooling system in addition to the prestressed and mild reinforcement

GREEN MIXTURES Although in many ways they are similar to conventional concrete, mixtures containing large amounts of slag cement have some unique properties that affect design and construction. These include rate of strength gain, finishing behavior, and ability to form fine details. The rate of strength gain can have a significant impact on the construction schedule. Because the elevated slabs were post-tensioned, the time between concrete placement and slab stressing was a critical-path item. Typically, a 5000 to 6000 psi (34 to 41 MPa) post-tensioned slab is Concrete international

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37

Fig. 5: Typical reinforcement details at the intersection of the columns and the post-tensioned beams for the two lateral forceresisting frames

Fig. 4: Reinforcement for a typical structural wall at the level detailed as a plastic hinge region

required to reach 3000 psi (21 MPa) before the strands can be stressed. Most conventional mixtures, under typical conditions, can meet this criterion in 3 to 5 days. The 50% slag cement mixtures used in the Brower Center often reached stressing strength within 5 days, but in a number of instances required 7 to 10 days. Because construction continued from late autumn through late spring, a wide range of temperatures was encountered. Placements during colder weather were typically slower to reach strength. As the Brower Center has only four elevated decks and the adjacent plaza portion was on a separate construction track, the net impact on the construction schedule was minor. Some mixtures that did not contain slag cement were used when slag cement was temporarily unavailable or in miscellaneous applications such as stair pan fill. This allowed comparison of the effects of slag cement inclusion under field conditions. Strength gain beyond the initial 7 to 10 days was similar for mixtures both with and without slag cement for values of ƒ' c between 3000 and 6000 psi (21 and 41 MPa). The initial 8000 psi (55 MPa) mixture containing 50% slag cement replacement that was used in the structural walls, however, was found to be particularly slow in achieving strength. Some samples required as much as 90 days to reach the full design

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strength. For the uppermost structural wall placement, slag cement was reduced to 40% of the total cementitious materials to speed strength gain. This mixture produced an average strength of 8600 psi (55 MPa) at 56 days. Figure 6 shows typical strength gain characteristics for the different mixtures used on the project.

NONSTRUCTURAL ISSUES WITH SLAG CEMENT CONCRETE There are additional considerations related to the use of slag cement beyond structural concerns. Material availability on the West Coast of the U.S. is sporadic. Most slag available in California is imported from China. The amount and quality of this slag have not been consistent, so many producers have not made provisions for its use. Hanson Asphalt & Ready Mix, the Brower Center supplier, had to erect a temporary slag cement silo to service the project. Growing demand for slag cement, however, will perhaps lead to increased availability. Slag cement mixtures also required modified finishing operations. Initial set is somewhat delayed, and more bleed water rises during floating; more time must be allowed between floating and troweling. Additionally, control of evaporative moisture loss is important, so use of curing compounds can be helpful. Despite these issues, reports from the field indicated that finishing of slag cement concrete is relatively less difficult than finishing high fly ash content mixtures. The contractor also reported that the slag cement mixtures pumped and placed well, showing improved workability. Another characteristic of the high slag cement content mixtures was a tendency for formed surfaces to have rounded corners and edges. Bleed water expelled during

form vibration appeared to rinse out the cement paste at form joints, corners, and snap ties, leaving a sandy residue with a radius of 1/16 to 1/8 in. (1.5 to 3 mm). This was problematic where reveals, sharp corners, or other fine features were required in exposed surfaces. Patching provided a good final appearance, but further investigation is needed to determine how to adjust the mixtures to correct this behavior. High-volume slag cement concrete offered advantages in the interior environment as the whiter color of the concrete was included in the interior lighting design. The light color of the concrete walls and painted ceilings, with the long, narrow building footprint, allowed a 100% daylight design—no interior lighting is required under normal conditions. Exterior sun shades enhance this effect and are designed for optimal sun exposure, creating shade in summer months and allowing light infiltration in winter months.

Fig. 6: Comparison of strength development characteristics for concrete mixtures used in the Brower Center (1 ksi = 6.9 MPa)

TEAMWORK Sustainable design requires a systems design approach. If a building must be constructed where extreme events are highly likely, the structural system must be robust enough to ensure the building remains functional and not part of the recycling or waste streams. The structural material must be selected to reduce energy demand and carbon footprint. If it can also help optimize thermal and lighting systems, then the architectural and engineering teams must work together to achieve those efficiencies. The David Brower Center exemplifies these concepts. Though not yet widespread in practice, the advantages offered by these concepts and systems are being increasingly recognized and used. References 1. Panian, L.; Steyer, M.; and Tipping, S., “Post-Tensioned Concrete Walls for Seismic Resistance,” PTI Journal , V. 5, No. 1, July 2007, pp. 7-16. 2. Panian, L.; Steyer, M.; and Tipping, S., “Post-Tensioned Shotcrete Shearwalls,” Concrete International , V. 29, No. 10, Oct. 2007, pp. 39-45. 3. “Minimum Design Loads for Buildings and Other Structures (ASCE/SEI 7-05),” American Society of Civil Engineers, Reston, VA, 2005, 388 pp. 4. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-05) and Commentary (318R-05),” American Concrete Institute, Farmington Hills, MI, 2005, 430 pp. 5. Priestley, M.J.N.; Calvi, G.M.; and Kowalsky, M.J., Displacement Based Seism ic Design of Structures, IUSS Press, Pavia, Italy, 2007, 721 pp. 6. Paulay, T., and Priestley, M.J.N., Seismic Design of Reinforced Concrete and Masonry Buildings , John Wiley & Sons, New York, NY, 1992, pp. 389-416. Selected for reader interest by the editors.

PROJECT CREDITS Architect: Solomon E.T.C., San Francisco, CA Owner/Developer: Equity Community Builders,

San Francisco, CA / RCD, Berkeley, CA Contractor: Cahill Contractors, San Francisco, CA Concrete Supplier: Hanson Asphalt & Ready Mix, Berkeley, CA

Mark Stevenson is an Associate at Tipping Mar +associates in Berkeley, CA. He is a licensed structural and civil engineer in California with more than 10 years of experience in the design of steel, concrete, and wood structures with an emphasis on multi-unit residential housing. He is a graduate of the University of California (UC)-Berkeley and the University of Michigan with a master’s degree in structural engineering. Leo Panian is an Associate at Tipping Mar +associates in Berkeley, CA. He is a licensed structural and civil engineer in California with more than 15 years of experience specializing in the design of steel and concrete structures with particular expertise in seismic engineering. He is a graduate of UC-Berkeley and UC-San Diego with a master’s degree in structural engineering. Concrete international

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ACI Spring 2009 Convention March 15-19, 2009 Marriott Rivercenter, San Antonio, TX *

SPECIAL SP ECIAL EVENTS A

ttendees of the ACI Spring 2009 Convention in San Antonio will have the opportunity to attend a variety of special events and social gatherings. ACI has worked closely with the ACI San Antonio Chapter to create and plan special events for everyone to enjoy. Here are some of the special events you can enjoy this spring!

Sunday, March 15, 2009 Student Concrete FRP Composites and Concrete Construction Competitions * Opening Session and Awards Program * Opening Reception Monday, March 16, 2009 * Student Lunch

Tuesday, March 17, 2009 Contractors’ Day Lunch * Concrete Mixer—A Night in Old San Antonio!

Wednesday, March 18, 2009 * CMC Texas Technical Tour * International Lunch

* *more information on each of the special events being offered, please visit www.aciconvention.org. For Register onsite at the Marriott Rivercenter in Salons G-I.

SAN ANTONIO!

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DECEMBER 2008

/ Concrete international Concrete international

Infrastructure - Concrete Practice & Placement

Investigating Construction Methods for Longtan Dam An experimental study of surface treatments for roller-compacted concrete

BY LEI YANG AND JONATHAN J. SHI

oller-compacted concrete (RCC) is zero-slump concrete placed and compacted with earth-moving and paving equipment, such as dump trucks, bulldozers, and vibratory rollers. Following its birth in the 1960s, RCC became widely used to build pavements and dams. Since building its first RCC dam in 1986 at Fujian Province, China has made significant progress and breakthroughs in dam style, raw materials, design, and construction methods1,2 and will soon be home to the world’s tallest RCC dam with RCC currently being placed. Longtan Dam, started on July 1, 2001, and scheduled to be completed in December 2009, will have a height of 710 ft (216.5 m).3 Longtan Dam is located in a semi-tropical climatic zone in Guangxi Province, China. Weather conditions in this region are characterized by hot temperatures and a long rainy season. With rapidly changing conditions that include 84 days per year with a rainfall of 0.024 to 0.4 in. (0.6 to 10 mm) and high temperatures up to 102 °F (39 °C) in July, the weather can seriously disrupt RCC construction. Due to its height and large volume, there are a great number of horizontal construction joints, and many of them may become cold joints (surfaces aged beyond initial set) during construction. In this study, different methods for treating layer joints in the Longtan RCC project were analyzed. The objective was to identify an efficient, easy-to-use treatment method that can meet the bonding requirements. The findings will help ensure smooth construction and high construction quality.

R

BOND STRENGTH AT JOINTS RCC for dams is placed in layers 1 to 2 ft (0.3 to 0.6 m) thick across the full width and length of the dam before

proceeding with the next layer.4 Bond strength at the joint between two adjacent layers is one of the most important factors to ensure the dam’s integrity and stability against high water pressure from the reservoir, to prevent seepage along the joints, and to resist seismic activity. An effective approach to accomplishing high bond strength is to start constructing a new layer on top of an existing layer before the lower layer reaches initial set. If an RCC layer cannot be covered by a new layer before initial set, a cold joint may be produced that will become the weakest link in the RCC dam. Shear strength, characterized by cohesion and an internal friction coefficient, is commonly used to measure bond strength at joints.5 Studies have shown that shear strength can be significantly improved when the joint is properly treated by washing, brushing, and cleaning the surface, and placing bedding materials before the upper layer of RCC is placed. Conclusions about the effectiveness of different treatment methods, however, are not consistent.

SPECIMENS The RCC constituents and mixture proportions were based on the design specifications for the Longtan Dam provided by the Midsouth Design & Research Institute of China and are shown in Table 1. The three mixtures used for the specimens had cementitious materials contents contents of 337, 303, and 270 lb/yd3 (200, 180, and 160 kg/m3 ). A volume of retarding admixture a dmixture equal to 0.4% of the cementitious materials volume was added to each mixture to extend setting time. Time intervals of 4, 12, 24, and 72 hours between placement of the first and second layers were investigated. Concrete international

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Two bedding materials, a cement-fly ash slurry slur ry and cement mortar, mortar, were used to treat the surface between the layers. For comparison, the untreated joint with no bedding material was also

included. Mixture proportions for the bedding materials are shown in Table 2. The bedding material was 0.4 to 0.6 in. (10 to 15 mm) thick and placed on a prepared surface cleaned by

TABLE 1 RCC MIXTURE PROPORTIONS AND PROPERTIES Material or property

RCC I

RCC II

RCC III

Water, lb/yd3 (kg/m3 )

125 (74)

123 (73)

121 (72)

Cement, lb/yd3 (kg/m3 )*

152 (90)

126 (75)

93 (55)

Fly ash, lb/yd3 (kg/m3 )†

185 (110)

177 (105)

177 (105)

1244 (738)

1244 (738)

1256 (745)

0 to 0.8 in. (0 to 20 mm)

757 (449)

758 (450)

765 (454)

0.8 to 1.6 in. (20 to 41 mm)

1010 (599)

1011 (600)

1020 (605)

1.6 to 3.2 in. (41 to 81 mm)

757 (449)

758 (450)

765 (454)

1.35 (0.80)

1.21 (0.72)

1.08 (0.64)

0.370

0.405

0.450

337 (200)

303 (180)

270 (160)

4195 (2489)

4224 (2506)

4232 (2511)

5.0

4.5

5.0

Sand, lb/yd3 (kg/m3 ) Aggregate, lb/yd3 (kg/m3 ): ‡

Retarding admixture, lb/yd3 (kg/m3 )§ /

w cm

Cementitious materials, lb/yd3 (kg/m3 ) Density, lb/yd3 (kg/m3 ) Vibrating compaction (VC) value||

*Guangxi province Liuzhou cement factory production “YuFeng” 525# portland cement conforming to cement grade requirements with no alkali-aggregate reaction. †

Guangxi province Tiandong power plant production of Grade II fly ash.

‡ §

Crushed limestone with a 3 in. (76 mm) maximum aggregate size.

Zhejiang province Longyou admixture factory production ZB-I RCC15 retarding type,

water-reducing admixture. ||

The VC value is used to measure the consistency of RCC in China.

TABLE 2: BEDDING MATERIAL MIXTURE PROPORTIONS AND PROPERTIES Material or property

Cement-fly ash slurry Cement mortar

rough brushing prior to placing the bedding material. All of the specimens were constructed in a trough in a controlled laboratory environment. The trough was 2 ft (600 mm) deep, 20 ft (6 m) long, 9 ft (2.8 m) wide, and could hold two 3 in. (75 mm) thick compacted layers. The following procedure was used to construct the specimens: ■ Dump and spread the lower loose layer of RCC about 4.7 in. (120 mm) thick; ■ Compact the lower layer with a vibratory roller at the design speed and number of passes; ■ Wait for the time interval being studied, prepare the joint surface, and place a layer of bedding material; ■ Place the upper layer of RCC on the bedding material; ■ Compact the upper layer with a vibratory roller at the design speed and number of passes; ■ Sawcut six 6 x 6 in. (150 x 150 mm) specimens from the 6 in. (150 mm) thick RCC slab; ■ Cure the specimens; and ■ Measure the shear strength of the specimens at the joints. This procedure was adopted to simulate the actual construction conditions for the project. The specimens were constructed during the summer under relatively high temperature and humidity conditions that were similar to actual construction construction conditions. Therefore, no additional measures were taken to control temperature and humidity during the experiment.

Water, lb/yd3 (kg/m3 )

656 (389)

320 (190)

Cement, lb/yd3 (kg/m3 )*

1200 (712)

366 (217)

Fly ash, lb/yd3 (kg/m3 )†

1468 (871)

549 (326)

—

2607 (1547)

16 (9.5)

4 (2.2)

TESTING AND RESULTS

0.246

0.350

Cementitious materials, lb/yd3 (kg/m3 )

2668 (1583)

915 (543)

Measured density, lb/yd3 (kg/m3 )

3069 (1821)

3833 (2274)

Both peak shear stress and sliding friction tests were conducted. Based on the Coulomb formula, shear stress τ can be expressed as:

Sand, lb/yd3 (kg/m3 ) Retarding admixture, lb/yd3 (kg/m3 )‡ /

w cm

*Guangxi province Liuzhou cement factory production “YuFeng” 525# portland cement conforming to cement grade requirements with no alkali-aggregate reaction. †

τ = C ′ + f ′ σ

Eq. (1)

Guangxi province Tiandong power plant production of Grade II fly ash.

‡

Zhejiang province Longyou admixture factory production ZB-I RCC15 retarding type,

water-reducing admixture.

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where τ is the peak shear stress at the layer joint, σ is the normal stress

at the joint surface, C ′ is the cohesion, and f ′ is the internal friction coefficient on the surface of the layer joint. The internal friction coefficient is often described in terms of the friction angle φ, where f ′= tan φ. A normal stress of 109, 218, 326, or 435 psi (0.75, 1.50, 2.25, or 3.00 MPa) was imposed on the specimen during the test. Under each normal stress, the shear was increased until large horizontal displacements were recorded. By plotting the measured σ and τ values and using the least squares method to determine a best-fit straight line through the data points, the values of C ′ and f ′ were determined. The sliding friction test was performed on each specimen after the peak shear stress was reached. The sliding friction strength was plotted and a

straight line was fitted to the data to yield an apparent cohesion ( C ) and sliding friction coefficient ( f ). A higher sliding friction indicated a stronger material along the joint interface.4 Effect of time interval To determine the effect of the time interval between placing the upper and lower layers, combinations of four time intervals and three treatment methods were studied. All specimens were tested at an age of 180 days and were made of RCC with a cementitious materials content of 337 lb/yd3 (200 kg/m3 ). The value of τ calculated using Eq. (1) at σ = 435 psi (3.0 MPa) is listed in Table 3. The value in the table is the average value of τ for the three treatment methods at a given

TABLE 3: SHEAR STRENGTH RESULTS FOR SPECIMENS CONSTRUCTED WITH DIFFERENT TIME INTERVALS BETWEEN CASTING OF UPPER AND LOWER LAYERS OF RCC Peak shear strength Time interval, hours

4

12

24

72

τ†,

C ′,

Joint treatment*

psi (MPa)

N

φ,

psi (MPa)

f ′

deg

640 (4.41)

1.44

55

1266 (8.73)

S

595 (4.10)

1.73

60

1347 (9.29)

M

940 (6.48)

0.99

45

N

408 (2.81)

1.75

S

457 (3.15)

M

Sliding friction strength , psi (MPa)

C ,

τ,

psi (MPa)

φ,

psi (MPa)

f

deg

96 (0.66)

1.27

52

648 (4.47)

122 (0.84)

1.11

48

605 (4.17)

1371 (9.45)

38 (0.26)

1.35

54

625 (4.31)

60

1169 (8.06)

22 (0.15)

1.31

53

592 (4.08)

1.99

63

1323 (9.12)

122 (0.84)

1.04

46

574 (3.96)

590 (4.07)

1.70

60

1330 (9.17)

88 (0.61)

0.91

42

484 (3.34)

N

402 (2.77)

1.38

54

1002 (6.91)

55 (0.38)

1.21

50

582 (4.01)

S

555 (3.83)

1.44

55

1182 (8.15)

16 (0.11)

1.18

49

529 (3.65)

M

822 (5.67)

0.98

44

1249 (8.61)

94 (0.65)

0.89

42

482 (3.32)

N

297 (2.05)

1.47

56

937 (6.46)

171 (1.18)

0.88

41

554 (3.82)

S

524 (3.61)

1.35

53

1111 (7.66)

29 (0.20)

1.09

47

503 (3.47)

M

856 (5.90)

0.92

43

1256 (8.66)

155 (1.07)

0.73

36

473 (3.26)

1329 (9.16)

1273 (8.78)

1144 (7.89)

1101 (7.59)

, psi (MPa)

627 (4.32)

550 (3.79)

531 (3.66)

511 (3.52)

*Joint treatment method: N = no treatment; S = cement-fly ash slurry; and M = cement mortar. †

τ

= C + f × 3.0 (MPa); τ = C × 435 (psi)


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time interval. Values of C ′ and f ′ corresponding to different time intervals are also plotted in Fig. 1. Table 3 shows that the peak shear strength at a layer joint decreased significantly when the time interval increased from 4 to 72 hours under the

conditions tested. For joints with cement mortar bedding material, τ decreased from 1370 to 1256 psi (9.45 to 8.66 MPa) when the time interval increased from 4 to 72 hours. Sliding friction strength shows the same trend. Table 3 also shows that joints with bedding

(a)

(b)

Fig. 1: Bond strength properties produced by the tested surface treatment methods at various time intervals between placing the upper and lower layers of RCC: (a) cohesion C ′ at zero normal stress; and (b) internal friction coefficient f ′ (1 psi = 6.89 kPa) .

TABLE 4: SHEAR STRENGTH RESULTS FOR SPECIMENS CONSTRUCTED WITH DIFFERENT RCC CEMENTITIOUS MATERIALS CONTENTS Cementitious materials content, lb/yd3 (kg/m3 )

337 (200)

303 (180)

270 (160)

Peak shear strength C ′,

Joint treatment*

psi (MPa)

N

τ†, φ,

psi (MPa)

f ′

deg

402 (2.77)

1.38

54

1002 (6.91)

S

555 (3.83)

1.44

55

1182 (8.15)

M

822 (5.67)

0.98

44

N

370 (2.55)

1.41

S

653 (4.50)

M

Sliding friction strength , psi (MPa)

C ,

psi (MPa)

MARCH 2009

φ,

psi (MPa)

f

deg

55 (0.38)

1.21

50

582 (4.01)

16 (0.11)

1.18

50

529 (3.65)

1249 (8.61)

94 (0.65)

0.89

42

482 (3.32)

55

983 (6.78)

38 (0.26)

1.27

52

590 (4.07)

1.17

49

1231 (8.48)

68 (0.47)

1.07

47

534 (3.68)

612 (4.22)

1.42

55

1230 (8.48)

62 (0.43)

0.99

45

493 (3.40)

N

328 (2.26)

1.44

55

954 (6.58)

51 (0.35)

1.26

52

599 (4.13)

S

635 (4.38)

1.17

49

1146 (7.90)

88 (0.61)

1.04

46

541 (3.73)

M

690 (4.76)

1.18

50

1204 (8.30)

55 (0.38)

1.10

48

534 (3.68)

1144 (7.89)

1127 (7.77)

1101 (7.59)

*Joint treatment method: N = no treatment; S = cement-fly ash slurry; and M = cement mortar.

44

τ,


, psi (MPa)

531 (3.66)

540 (3.72)

558 (3.85)

materials had larger peak shear stresses than joints without treatment. The values in Table 3 show that the shear strength at the joint decreased as the time interval increased regardless of the material used to treat the joint. It is therefore obvious that the most effective approach to ensure the quality of RCC construction is to effectively plan and manage site operations to minimize the time interval between two adjacent layers. Table 3 also shows that for any time interval, the peak shear stress with cement mortar bedding was higher than that with cement-fly ash slurry. For time intervals of 4, 8, 24, and 72 hours, τ with cement mortar was 1.7, 0.5, 5.5, and 13% higher than that with cement-fly ash slurry, respectively. Effect of cementitious materials content To determine the effect on bond of the cementitious materials content of the RCC, combinations of three cementitious materials contents and three treatment methods were studied. All specimens were tested at an age of 180 days and a time interval between placing the upper and lower layers of 24 hours. Similar to the specimens tested to investigate the effect of time interval, τ was calculated using Eq. (1) at σ = 435 psi (3.0 MPa). The results are given in Table 4. Values of C ′ and f ′ corresponding to different cementitious materials contents are plotted in Fig. 2. The results in Table 4 show that the peak shear strength at the layer joint decreased when the cementitious materials content of RCC decreased from 337 to 270 lb/yd3 (200 to 160 kg/m3 ). When the joint was bedded with cement mortar, τ decreased from 1249 to 1204 psi (8.61 to 8.30 MPa) as the cementitious materials content of the RCC changed from 337 to 270 lb/yd3 (200 to 160 kg/m3 ).

These results indicate that bond strength can be improved by increasing the cementitious materials content. Effect of rainfall intensity Rainfall can negatively impact RCC construction by seeping into the RCC and changing the water-cementitious material ratio ( w/cm ) or washing away the cement and separating the mortar from the coarse aggregate. Because the rainy season at the Longtan Dam site lasts 4 months, there is significant concern about rainfall reducing bond strengths below the design requirements. Rainfall was simulated for two scenarios. In Scenario 1, rain occurs during the interval between placement of two adjacent layers. In Scenario 2, rain occurs while the upper layer is under construction. In both scenarios, the time interval between the start of construction for the lower layer and the completion of the upper layer was less than the allowable time interval. Therefore, no bedding material was applied to the top of the bottom layer. All specimens were tested at a nominal age of 90 days. The normal stress σ and shear stress at the joint τ obtained from the experiments are shown in Table 5. The values of C ′, f ′, and φ obtained from the σ and τ values are also listed in the last three columns of Table 5. The values of C ′ and f ′ are plotted as a function of rainfall intensity in Fig. 3 along with the values of C ′ and f ′ required for the design. For Scenario 1, the results show that if rain falls directly on the lower lift surface before construction of the upper lift starts and the upper layer is completed within the allowable time interval, rainfall doesn’t have a significant impact on C ′ and f ′. Figure 3 also shows that when rainfall intensity reached 0.31 in./h (8 mm/h), shear strength at the joint could still meet the design requirements.

(a)

(b)

Fig. 2: Bond strength properties produced by the tested surface treatment methods for specimens made with various RCC cementitious materials contents: (a) cohesion C ′ at zero normal stress; and (b) internal friction coefficient f ′ (1 psi = 6.89 kPa, 1 lb/yd 3 = 0.593 kg/m3 ) .


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In scenario 2, C ′ and f ′ decreased rapidly as rainfall intensity increased. As rainfall intensity increased, more mortar floated on the interface and the surface became the weakest part of the concrete. Figure 3 shows that if rainfall intensity qi exceeded 0.12 in./h (3 mm/h), shear strength could not meet the design requirements. In this scenario, nearly all specimens failed at the layer joint.

SURFACE DRYING During construction of the Longtan RCC dam, adverse weather conditions including high temperature, high wind velocity, and intense solar radiation can dry the surface of the RCC and bedding materials, resulting in reduced bond strength at the joint. High ambient temperatures can also cause the concrete’s temperature to increase during transportation, dumping, spreading,

TABLE 5: MEASURED σ AND τ VALUES AND DERIVED SHEAR STRENGTH AT THE JOINT FOR SPECIMENS SUBJECTED TO DIFFERENT RAINFALL SCENARIOS qi,

Scenario*

Scenario 1

Scenario 2

in./h (mm/h)

σ1/τ1, psi/psi (MPa/MPa)




C ′,

psi (MPa)

0 (0)

119/745 (0.82/5.14)

186/856 (1.28/5.90)

348/1094 (2.40/7.54)

435/1291 (3.00/8.90)

0.10 (2.6)

117/686 (0.81/4.73)

194/811 (1.34/5.59)

335/1025 (2.31/7.07)

0.20 (5.0)

115/661 (0.79/4.56)

186/764 (1.28/5.27)

0.31 (8.0)

112/640 (0.77/4.41)

0.10 (2.6)

f ′

φ, deg

541 (3.73)

1.67

59

432/1208 (2.98/8.33)

490 (3.38)

1.64

59

339/1008 (2.34/6.95)

431/1160 (2.97/8.00)

476 (3.28)

1.58

58

183/757 (1.26/5.22)

328/996 (2.26/6.87)

437/1146 (3.01/7.90)

470 (3.24)

1.57

58

113/657 (0.78/4.53)

190/786 (1.31/5.42)

339/1015 (2.34/7.00)

431/1170 (2.97/8.07)

477 (3.29)

1.60

58

0.20 (5.0)

110/599 (0.76/4.13)

184/748 (1.27/5.16)

350/935 (2.41/6.45)

437/1085 (3.01/7.48)

460 (3.17)

1.42

55

0.31 (8.0)

112/582 (0.77/4.01)

183/674 (1.26/4.65)

342/902 (2.36/6.22)

432/1017 (2.98/7.01)

428 (2.95)

1.37

54

* Scenario 1 = rainfall at a rate of qi occurs during the interval between placement of two adjacent layers. Scenario 2 = rainfall at a rate of qi occurs while the upper layer is under construction.

(a)

(b)

Fig. 3: Bond strength properties produced under two tested rainfall scenarios: (a) cohesion C ′ at zero normal stress; and (b) internal friction coefficient f ′ (1 psi = 6.89 kPa, 1 in. = 25.4 mm) .

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and compaction. These conditions can accelerate cement dehydration, accelerate initial set of the surface concrete, and shorten the allowable time interval between layers. Under high temperatures and windy, dry, sunny conditions, water loss will occur if the bedding material cannot be quickly covered with the next RCC layer. If the water loss is substantial, the bedding material surface will become dry and whitened, and the material will stop developing strength. When this occurs, the bedding materials stop improving bond between the layers and act as a soft interlayer that significantly reduces bond strength.6 Although not investigated during this study, effective measures to reduce water evaporation or mitigate its impact on construction quality include reducing the placing temperature of the bedding materials and increasing the humidity at the surface. Reducing placing temperature can be accomplished by cooling the materials before or during mixing or by adding ice to the mixture. Increasing the humidity at the surface can lower the ambient temperature, slow the increase of vibratory compaction (VC) values, prevent drying, and lower the temperature of RCC and bedding materials. An effective measure for maintaining high relative humidity at the surface is to spray water fog into the air directly above the surface.

and cooperation of the Midsouth Design & Research Institute of China are also appreciated.

References 1. Wang, S.P., “Basic Experience and Achievements of the RCC Dam Construction in China,” Journal of Water Power , Vol. 20, No. 5, 1994, pp. 41-44. 2. Mei, Z., “New Development of RCC Dam Construction Techniques in China,” Journal of Water Power , Vol. 31, No. 16, 2005, pp. 54-56. 3. Special Council of Construction Technology of RCC Dam, “A Briefing of Roller Compacted Concrete Dam Construction Technology,”

Journal of China Water Resources, V. 10, 2004, pp. 26-27. 4. Dolen, T.P., and Tayabji, S.D., “Bond Strength of Roller Compacted Concrete,” Roller Compacted Concrete II , K.D. Hansen and L.K. Guice, eds., American Society of Civil Engineers, New York, 1988, pp. 170-186. 5. The Ministry of Water Resources of People’s Republic of China, “Construction Specifications for Hydraulic RCC (SL53-94),” Water Power Press, Beijing, China, 1994, pp. 1-55. 6. American Society of Civil Engineers, Roller-Compacted Concrete

(Technical Engineering and Design Guides as Adopted from the US Army Corps of Engineers, No. 5), ASCE Press, New York, 1994, pp. 1-49. Received and reviewed under Institute publication policies.

ENSURING QUALITY UNDER ALL CONDITIONS Bond strength between layers is critical for quality RCC construction. The most effective approach to improving bond strength is proper planning and management of the construction process to ensure the upper layer is constructed within the allowable time interval. If two layers cannot be constructed within the allowable time interval, properly treating the joint by applying bedding material can improve bond strength at the joint. In the laboratory experiments described in this article, cement mortar bedding material produced slightly higher bond strengths than cement-fly ash slurry. For either bedding material, the bond strength increased as the cementitious materials content in the RCC increased. If applied, bedding material should be covered as soon as possible during construction. Bond strength at a joint is also affected by weather conditions, especially if the conditions impact the w/cm of the bedding material or RCC. Increasing or decreasing the water content in the mixture to account for weather conditions may alleviate the impacts. Furthermore, reducing the placing temperature of bedding materials and applying fog spraying are also effective measures for controlling the water evaporation of bedding materials. Acknowledgments Professors H.X. Xiao, W.B. Lu, Z.G. Hu, and Y.H. Zhou are thanked for their inspiration and input to this research. The participation

Lei Yang has been a Teacher in the Department of Water Resource and Hydropower at Wuhan University since July 1996. He received his PhD in water resource and hydropower from Wuhan University in 2005. His major research efforts have been focused on construction and management of civil engineering structures, especially in water conservancy and hydropower projects such as designing, constructing, model testing, and project management. Jonathan J. Shi is a Professor in the Department of Civil, Architectural, and Environmental Engineering at the Illinois Institute of Technology and Director of the Center for Work Zone Safety and Mobility. His research interests include highway work zone safety and mobility, and modeling and simulation of construction operations. He is a registered professional engineer in Hong Kong and a member of the American Society of Civil Engineers, the Construction Management Association of America, and the Hong Kong Institution of Engineers. Concrete international

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From Rheology of Fresh Concrete to Casting Processes Correlating properties with field performance

BY NICOLAS ROUSSEL

hat are the final objectives of the extensive research that has been carried out in the last 50 years on the rheology of fresh concrete? A researcher’s answer might be: “the understanding of the correlation between mixture proportioning and rheological properties” or “the ability to correctly measure and quantify the rheological properties of concrete.” These points are of great interest, but a practitioner would probably answer: “the ability to predict whether or not a given concrete will correctly fill a given formwork.” A lot of research has been carried out to understand the correlation between mechanical properties and mixture proportioning, 1 and many tests have been developed to measure these mechanical properties, such as strength and delayed deformations. But many developments were also made to correlate the properties of the concrete to be cast with the structure to be built. This last step has been missing for years in the rheology field. Only recently have researchers from various parts of the world started working on cas ting prediction tools. It should be noted that this new research area has appeared on the scene at the same time as self-consolidating concrete (SCC). This extremely fluid type of concrete was expected to be the answer to casting problems. No matter how fluid a concrete is, however, there will always be formwork and reinforcement configurations that present casting problems.

W

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SCIENTIFIC BACKGROUND Fresh cementitious materials behave as fluids with a yield stress, which is the minimum stress for flow to occur. The behavior of fresh concrete is thus often approximated by a yield stress model of the following general form2,3: Eq. (1a) Eq. (1b) where τ00 is the yield stress, is the shear rate, and µ is the plastic viscosity. From a practical point of view, yield stress may be associated with filling capacity and, more generally, with whether or not concrete will flow or stop flowing under an applied stress, whereas plastic viscosity may be associated with the velocity at which a given concrete will flow once flow is initiated. In the field of concrete casting, unlike polymer or metal casting, the applied stress is mainly due to gravity, as injection under pressure is very rare. Although measurements of plastic viscosity have several practical applications, such as pumping and casting rates, yield stress is the most important parameter for formwork filling. If we consider, for instance, the casting of a wall such as the one in Fig. 1(a), a purely p

(a)

(b)

(c)

Fig. 1: Formwork filling process: (a) casting process; (b) final shape of the material in the case of a purely viscous fluid; and (c) final shape of the material in the case of a fluid with a yield stress

viscous fluid (one with a zero yield stress) would self level under the effect of gravity, as shown in Fig. 1(b). Gravity would indeed induce a pressure gradient in the fluid if the upper surface of the material is not horizontal. This pressure gradient would generate a shear stress in the material that creates a shear rate and forces the material to flow until the upper surface becomes horizontal and the pressure gradient at the origin of the flow has disappeared. The viscosity of the material will only play a role in the time needed to obtain a horizontal surface. In the case of a fluid with a yield stress, such as concrete, gravity and the pressure gradient also generate a shear stress. If this shear stress, which is a complex function of the formwork thickness and the density of reinforcement, becomes lower than the yield stress of the concrete, flow stops before the concrete self levels, as shown in Fig. 1(c). This example teaches us two things. First, the best way to fill formwork is to fill it with a purely viscous fluid, which is useless in practice as we will never be able to produce stable concrete with no yield stress at all. Second, to predict whether a given concrete will fill a given formwork, we must have the ability to measure the yield stress of the material to be cast. It must be noted that the knowledge of the yield stress at the end of the mixing phase may not always be sufficient to describe the behavior of fresh concrete after transportation from the concrete plant to the job site. A change in the material yield stress is often noted during this time period. In many cases, the material yield stress increases, causing a workability loss. Delayed actions of high-range water-reducing admixtures, however, may also decrease the material yield stress.

concrete containing coarse aggregate, however, largescale rheometers have been developed (BTRheom6, BML7, or two-point test8 ). Even though simpler and cheaper tests such as the slump test9 are still often preferred on the job site, these rheometers represent a big step forward in the field of concrete science. A discrepancy still exists, however, between the various rheometers.10,11 They give the same rheological classification of materials, but they do not give the same absolute values of the rheological parameters τ00 and µ . The slump test, the most common empirical test for fresh concrete, does not give any value of a physical parameter at all. In fact, the results could not be expressed in physical rheological units until recently. But it has also proved through the years to be able to classify different materials in terms of their abilities to fill formwork. Several attempts to relate slump to yield stress can be found in literature. Murata 12 first wrote of a relation between the final height of the cone and the yield stress of the material. Subsequent works established analogous relationships either for conical or cylindrical forms. 13-16 It’s recently been shown that two very different regimes (slump regime and spreading regime) may be identified, deriving two analytical solutions suitable for asymptomatic regimes, namely low-slump or largeslump flow diameter.17 Numerical simulations of the slump test were also carried out for the ASTM Abrams cone.18 An excellent agreement between the predicted and measured slumps over a wide range of yield stress was obtained. As an example, the obtained correlation18 between slump and yield stress for slump values ranging from 50 to 250 mm (2 to 10 in.) is written: p

Eq. (2) (SI units)

YIELD STRESS MEASUREMENTS In the case of cement pastes, yield stress may be measured using conventional rheological tools.4,5 For

Eq. (2) (in.-lb units) Concrete international

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1200

Spread length, mm

1100 1000 900 800 700 600 500 Yield stress/specific gravity, Pa

(a)

(b)

400 0

10

20

30

40

50

60

Fig. 2: The LCPC Box test for SCC: (a) the SCC is slowly poured into the box at one end; and (b) correlation between measured spread length and a yield stress of the tested material (1 in. = 25.4 mm, 1 psi = 6890 kPa)

where S is the measured slump, mm (in.), τ00 is the yield stress, Pa (psi), and ρ is the density of the concrete, kg/m3 (lb/ft3 ). In the case of SCC, it was demonstrated that the slump flow test cannot be universally correlated to the rheological parameters of the concrete.19 Indeed, the thickness of the sample when flow stops is of the same order as the largest particles. This does not mean that slump flow cannot be used as an acceptance test. For a given SCC with a given granular skeleton, the s lump flow value is indeed a handy tool to spot, for example, a variation in water amount during production. But the measured spread (or slump flow value) cannot be directly and universally correlated to the yield stress of the SCC. An alternate test method is the recently proposed “LCPC Box” test shown in Fig. 2(a). The width of the channel is 200 mm (7.9 in.) and the length is 1200 mm (47.2 in.). The studied volume of SCC is the same as the one used in the slump flow test, 6 L (0.21 ft3 ). As the flow is almost unidirectional, the thickness of the sample at stoppage for the same sample volume is greater than in the slump flow test. Moreover, it was verified that the final shape does not depend on the pouring speed of the concrete to be tested. This new test is a cheap and easy way to measure the yield stress of fluid concrete when trying to reach the optimum mixture design or to compare the rheology of various SCC mixtures. Unlike the slump flow test, the measured spread length is correlated to the yield stress of the material via the unique law19, 20 shown in Fig. 2(b). As an intermediate conclusion, it should be kept in mind that these correlations between geometrical measurements, such as slump or spread length, allow

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measurement of the yield stress of any concrete without the use of a rheometer. They easily give access to this fundamental and intrinsic rheological parameter and therefore open the door to the use of this measurement in casting prediction tools.

CASTING PREDICTIONS The ideal mixture proportions for fluid concrete are located somewhere between two opposite objectives. The concrete has to be as fluid as possible to ensure that it will fill the formwork under its own weight, but it has to be stable enough to withstand the high strain rates generated by flow in a confined zone. Therefore, a compromise between stability and fluidity has to be reached. The most straightforward approach is to find the minimum fluidity (or workability) that will guarantee adequate filling of the formwork and assume that this minimum fluidity will ensure the maximum acceptable stability. The only traditional way to do this is to try various mixture proportions, cast a full-size element with each of them, and choose the most suitable mixture (if there is one). This is expensive and time consuming and does not guarantee an answer. In the case of sufficiently fluid concretes, however, the numerical tools of non-Newtonian fluid mechanics allow numerical simulation of the casting process and, for a very low cost, the determination of the minimum fluidity. The applicability of the viscoplastic divided element method (VDEM) for simulating the flow of concrete in a reinforced beam section and the filling of a reinforced wall has already been demonstrated,21 and the applicability of 2-D VDEM to simulate the flow of fresh concrete in formwork has been confirmed.22 The results of a form-filling

experiment in a vertical wall have also been compared with the corresponding 3-D simulation.23 The results show high correlation with respect to detection of the free surface location, dead zones, and particle paths. Numerical simulations were also recently applied to an industrial casting of a very high-strength concrete precambered composite beam.24 The results of the simulations carried out for various values of the rheological parameters helped determine the value of the minimum fluidity needed to cast the element. The LCPC Box mentioned previously was used to measure the yield stress of the prepared SCCs. The numerical calculations were able to predict the experimental observations carried out during two trial castings (Fig. 3). In the case of SCC with 120 Pa (0.017 psi) yield stress, some voids were found below the steel girders after the removal of the form 1 day after casting. After casting SCC with 60 Pa (0.0087 psi) yield stress, no voids were visible. Although the assumptions needed to carry out the simulations were overly simplistic (only 2-D simulations were carried out), a satisfactory agreement was found between the predicted and actual flow. It is my opinion that, in the future, computational modeling of flow could become a practical tool for allowing the simulation of either total form filling or detailed flow behavior such as particle migration and formation of granular arches between reinforcement (also known as “blocking”).25,26 These methods could then be gathered to create a casting process engineering toolbox and bring rheology from the laboratory to the field.

Fig. 3: Comparison between numerical predictions and actual casting of a precambered beam. The concrete was first poured from one side of the steel girder (light gray). The concrete was then poured from the other side of the steel girder to complete the filling (dark gray): (a) actual casting results using concrete with a yield stress of 120 Pa (0.017 psi); (b) numerical simulation results for concrete with a yield stress of 120 Pa (0.017 psi); (c) actual casting results using concrete with a yield stress of 60 Pa (0.0087 psi); and (d) numerical simulation results for concrete with a yield stress of 60 Pa (0.0087 psi) (1 in. = 25.4 mm)

References 1. De Larrard, F., Concrete Mixture Proportioning: A Scientific Approach , E&FN

Spon, London, 1999, 421 pp. 2. Hu, C., and de Larrard, F., “The Rheology



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of Fresh High-Performance Concrete,” Cement and Concrete Research, V. 26, No. 2, Feb. 1996, pp. 283-294.

3. Tatersall, G.H., and Banfill, P.G.F., The Rheology of Fresh Concrete, Pitman, London, 1983, 356 pp.

4. Shaughnessy, R., and Clark, P.E., “The Rheological Behavior of Fresh Cement Pastes,” Cement and Concrete Research, V. 18, No. 3, May 1988, pp. 327-341. 5. Nehdi, M., and Rahman, M.-A., “Estimating Rheological Properties of Cement Pastes Using Various Rheological Models for

Rheology , V. 49, No. 3, May-June 2005, pp. 705-718.

18. Roussel, N., “Correlation between Yield Stress and Slump: Comparison between Numerical Simulations and Concrete Rheometers Results,” Materials and Structures, V. 39, No. 4, May 2006, pp. 501-509. 19. Roussel, N., “The LCPC BOX: A Cheap and Simple Technique for Yield Stress Measurements of SCC,” Materials and Structures, V. 40, No. 9, Nov. 2007, pp. 889-896. 20. Nguyen, T.L.H.; Roussel, N.; and Coussot, P., “Correlation

Different Test Geometry, Gap and Surface Friction,” Cement and

between L-Box Test and Rheological Parameters of a Homogeneous

Concrete Research, V. 34, No. 11, Nov. 2004, pp. 1993-2007.

Yield Stress Fluid,” Cement and Concrete Research, V. 36, No. 10,

6. Hu, C.; de Larrard, F.; Sedran, T.; Boulay, C.; Bosc, F.; and Deflorenne, F., “Validation of BTRHEOM, the New Rheometer for

Oct. 2006, pp. 1789-1796. 21. Mori, H., and Tanigawa, Y., “Simulation Methods for Fluidity

Soft-to-Fluid Concrete,” Materials and Structures, V. 29, No. 10, Dec. 1996,

of Fresh Concrete,” Memoirs of the School of Engineering, Nagoya

pp. 620-631.

University , V. 44, No. 1, 1992, pp. 71-134.

7. Operating manual, the BML viscometer, the viscometer 4, ConTec, 2000.

22. Kitaoji, H.; Tanigawa, Y.; Mori, H.; Kurokawa, Y.; and Urano, S., “Flow Simulation of Fresh Concrete Cast into Wall Structure by

8. Tatersall, G.H., and Bloomer, S.J., “Further Development of the Two-Point Test for Workability and Extension of its Range,” Magazine of Concrete Research, V. 31, Dec. 1979, pp. 202-210.

9. ASTM C143-90, “Standard Test Method for Slump of Hydraulic

Viscoplastic Divided Space Element Method,” Transactions of the Japan Concrete Institute, V. 16, 1996, pp. 45-52.

23. Thrane, L.N.; Szabo, P.; Geiker, M.; Glavind, M.; and Stang, H., “Simulation and Verification of Flow in SCC Test Methods,”

Cement Concrete,” ASTM International, West Conshohocken, PA,

Proceedings of the 4th International RILEM Symposium on SCC ,

1990, 3 pp.

Chicago, IL, 2005.

10. Banfill, P.; Beaupré, D.; Chapdelaine, F.; de Larrard, F.;

24. Roussel, N.; Staquet, S.; D’Aloia Schwarzentruber, L.; Le Roy, R.;

Domone, P.; Nachbaur, L.; Sedran, T.; Wallevik, O.; and Wallevik, J.E.,

and Toutlemonde, F., “SCC Casting Prediction for the Realization of

“Comparison of Concrete Rheometers: International Tests at LCPC

Prototype VHPC-Precambered Composite Beams,” Materials and

(Nantes, France) in October, 2000,” C.F. Ferraris and L.E. Brower,

Structures, V. 40, No. 9, Nov. 2007, pp. 877-887.

eds., National Institute of Standards and Technology Interagency Report (NISTIR) 6819, 2001, 147 pp. 11. Beaupré, D.; Chapdelaine, F.; Domone, P.; Koehler, E.; Shen, L.; Sonebi, M.; Struble, L.; Tepke, D.; Wallevik, O.; and Wallevik, J.E.,

25. Martys, N., and Ferraris, C.F., “Simulation of SCC Flow,” Proceedings of the First North American Conference on the Design and Use of Self-Consolidating Concrete, Chicago, IL., Nov. 2002, pp. 27-30.

26. Roussel, N.; Geiker, M.R.; Dufour, F.; Thrane, L.N.; and Szabo, P.,

“Comparison of Concrete Rheometers: International Tests at MB

“Computational Modeling of Concrete Flow: General Overview,”

(Cleveland, OH, USA) in May, 2003,” C.F. Ferraris and L.E. Brower,

Cement and Concrete Research, V. 37, No. 9, Sept. 2007, pp. 1298-1307.

eds., National Institute of Standards and Technology Interagency Report (NISTIR) 7154, 2004, 63 pp.

Selected for reader interest by the editors.

12. Murata, J., “Flow and Deformation of Fresh Concrete,” Materials and Structures, V. 17, No. 2, Mar. 1984, pp. 117-129.

13. Schowalter, W.R., and Christensen, G., “Toward a Rationalization of the Slump Test for Fresh Concrete: Comparisons of Calculations and Experiments,” Journa l of Rheolo gy , V. 42, No. 4, July 1998, pp. 865-870. 14. Pashias, N.; Boger, D.V.; Summers, J.; and Glenister, D.J., “A Fifty Cent Rheometer for Yield Stress Measurement,” Journal of Rheology , V. 40, No. 6, Nov. 1996, pp. 1179-1189.

15. Clayton, S.; Grice, T.G.; and Boger, D.V., “Analysis of the Slump Test for On-Site Yield Stress Measurement of Mineral Suspensions,” International Journal of Mineral Processing , V. 70, No. 1-4, June 2003, pp. 3-21. 16. Saak, A.W.; Jennings, H.M.; and Shah, S.P., “A Generalized Approach for the Determination of Yield Stress by Slump and Slump Flow,” Cement and Concrete Research, V. 34, No. 3, Mar. 2004, pp. 363-371. 17. Roussel, N., and Coussot, P., “‘Fifty-Cent Rheometer’ for Yield Stress Measurements: From Slump to Spreading Flow,” Journal of

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Nicolas Roussel is in charge of research activities concerning mixture proportioning and casting processes of cementitious materials at the French Laboratoire Central des Ponts et Chaussées (LCPC) in Paris, France. He is the author of more than 40 papers dealing with the rheology of suspensions in general and of cement pastes and concretes in particular. He is a member of the RILEM Bureau and Chair of the RILEM Technical Committee dealing with numerical simulations of fresh concrete. In 2007, he received the RILEM Robert L’Hermite Medal and the French Association for Mechanics Jean Mandel Award.

Detailing Corner Sloped Versus Stepped Footings for Walls G

enerally, it’s most economical to place wall footings at a constant elevation. If the site or finished grade slopes along the length of the wall, however, the footing may end up a considerable distance below finished grade. This is clearly not economical, as it requires extra excavation and material. Two other options are therefore preferred (Fig. 1):  Slope the footing with the site so its depth below the finished grade is nearly constant along its length; or  Step the footing so its depth below finished grade is not excessive at any point along its length.

prevent the concrete from flowing downhill, which may lead to segregation. Alternatively, the top of the form may have to be closed. Because of these challenges, most engineers and contractors prefer to use stepped footings instead of sloped footings.

CONSIDERATIONS FOR STEPPED FOOTINGS As with any aspect of a design, cost should be considered before a system is selected. If the slope of the finished grade is less than 2 ft (0.6 m) for a 20 to 30 ft (6 to 9 m) long wall, a lower but constant bottom bearing

SLOPED FOOTING ISSUES The sloped footing option may seem appealing because of the simple geometry and apparent ease in formwork construction. It does, however, create the following construction issues (Fig. 2):  Vertical wall bars above the footing will have different lengths, creating major challenges in the fabrication plant and on the job site. Two of these—managing the inventory and placing the bars in their correct locations— can be eased by detailing the bars with variable lap splice lengths. This will, however, increase the quantity of vertical reinforcement;  Horizontal reinforcing bars in the lower portion of the wall will also have different lengths because they are interrupted by the sloped footing. If constant length horizontal bars are used at the wall base, they can be fanned out, but this will create a variable ver tical spacing of the reinforcing bars;  Sloped footings will require trapezoidal formwork. This will require modifications to standard rectangular formwork;  A sloped footing could be unstable, particularly on a very steep slope; and  Concrete placement and finishing could be difficult, and a stiff concrete mixture might be required to

DETAILING CORNER Joint ACI-CRSI Committee 315-B, Details of Concrete Reinforcement— Constructibility, has developed forums dealing with constructibility issues for reinforced concrete. Staff at the Concrete Reinforcing Steel Institute (CRSI) are presenting these topics in a regular series of articles. CRSI staff will also respond to requests for information (RFIs) regarding design, detailing, and construction. If you’d like to suggest an article topic or submit an RFI for this feature, please send an e-mail to Neal Anderson, CRSI’s Vice President of Engineering, at nanderson@ crsi.org with the subject line “Detailing Corner.”


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Wall

Wall Finished grade

Finished grade

Bottom may be sloped (a)

(b)

Fig. 1: There are two ways to construct footings for walls built at sloping grades: (a) slope the footing to match the change in finished grade elevation; or (b) step the footing at intervals that maintain the minimum footing depth

Nonrectangular formwork panel

Maximize the run

Variable bar lengths

Placement and finishing of concrete may be difficult Potential failure plane at base of footing

Minimize the number of steps

Use bars with only one bend Optional sloped footing bottom

Avoid using Z-shaped bars

Fig. 2: Construction issues for sloped footings

Fig. 3: Preferred details for stepped footings

elevation may be more economical than a stepped footing. For a very long wall, however, even a 1 ft (0.3 m) variation in the site elevation may make a stepped footing more economical. Communication with the contractor during the design phase regarding the number and length of steps can be very helpful. It’s generally more cost effective to minimize the number of steps. For example, it may be more economical to design for a 6 ft (1.8 m) change in elevation using three 2 ft (0.6 m) steps or two 3 ft (0.9 m) steps rather than six 1 ft (0.3 m) steps. This minimizes the number of wall sections to be detailed and formed. Before deciding on the footing step locations, however, consider the horizontal distance between them. Distances should preferably be multiples of available or standard form lengths. Before completing a design, it’s a good idea to communicate with area formwork contractors. The horizontal runs should be dimensioned in 2 or 4 ft (0.6 or

1.2 m) increments to conform to standard plywood or form system dimensions. Unless the site slopes drastically, try to keep a minimum horizontal run of 10 ft (3 m) for each step, if possible. Keep the detailing simple. Avoid using Z-shaped bars (Fig. 3). Their geometry may make it necessary to slant the riser out of plane to meet cover requirements for the treads. It’s also prudent to evaluate other footing options. For example, the individual spread footings or piers supporting grade beams shown in Fig. 4 may be more economical than a continuous spread footing option. Because the wall can span between footings or piers, similar configurations can be constructed without the grade beam. Situations can vary along the wall length, so it’s prudent to show specific details rather than generic details. This will expedite placing drawing preparation and perhaps minimize requests for information (RFIs).

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Wall Wall Finished grade Grade beam Grade beam

Isolated spread footing or Drilled pier

Fig. 4: Isolated spread footings or drilled piers, with or without a grade beam connecting them, are an alternative to sloped or stepped footings

CLOSURE The use of sloped or stepped footings depends on site conditions, finished grade elevations, finished wall slope, and various reinforcing bar placement and construction issues. Regardless of the footing system selected, the engineer is required to follow the design requirements of Section 15.9 in ACI 1 318-08. Section 15.9.1 requires that the angle of slope or depth and location of steps be such that the design requirements are satisfied at every section. Additionally, Section 15.9.2 requires footings designed as a unit to be constructed to ensure they act as a unit. References 1. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-08) and Commentary,” American Concrete Institute, Farmington Hills, MI, 2008, 465 pp. Thanks to Joint ACI-CRSI Committee 315 member Javed Malik, Jacobs Engineering Group, Houston, TX, for providing the information in this article. Selected for reader interest by the editors.



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To order new publications, use the for m on the Bookshelf page in the back of this magazine. You may contact ACI for additional information by phone at (248) 848-3800 or go to our online bookstore at www.concrete.org.

ACI 318-08 AND PCA NOTES ON CD-ROM ACI 318-08 and PCA Notes on ACI 318-08 are linked and indexed allowing Adobe® Acrobat® Reader to search, find, and print information. Order Code: Format: Prices:

31808CD.CI CD-ROM $199.50 (ACI members $150.00)

2009 MANUAL OF CONCRETE PRACTICE— MCP 2009 The American Concrete Institute’s 2009 Manual of Concrete Practice contains over 190 ACI committee standards and reports, including 24 new/revised publications. ACI’s Manu al o f Co ncr ete Pra ctic e is the most comprehensive concrete reference set available. It contains all of the widely used ACI concrete and masonry code requirements, specifications, guides, and reports. Additionally, it includes information about code requirements, deflection, cracking, durability problems, temperature control, nondestructive testing, and hundreds of other topics. A complete listing of publications included in the 2009 edition and additional optional formats including online

subscription, multi-user license, and more is available at www.concrete.org or by calling (248) 848-3800. Format

Order Code

Manual of Concrete Practice 6-Volume Set

MCP09PACK.CI

+ Index Manual of Concrete Practice CD-ROM Manual of Concrete Practice Hard Copy

and CD-ROM

MCPCD09.CI

MCPCD09PACK.CI

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$799.50 (ACI members $499.00)

$681.50 (ACI members $409.00)

$1185.50 (ACI members $711.00)

Spring 2009 Transition from Fluid to Solid: Re-Examining the Behavior of Concrete at Early Ages— SP-259 CD-ROM

Membership Matters. Visit the ACI Membership Directory www.concrete.org

Click the “Membership” tab • Quickly and easily obtain detailed contact information for other ACI members (members only); • Conduct detailed search by job category for ACI’s corporate members; • Local, regional, and international listings; • Open to the public (limited access) for business-development opportunities Connecting and networking with ACI members has never been easier. The new ACI Membership Directory is one of six new benefits available to all ACI members; visit www.concrete.org or call 248-848-3800 to learn what else is new! Verify your listing—only ACI members can be listed in this Directory. To opt out or modify your listing, simply login to www. concrete.org and click on “My Contact Information” or call 248-848-3800 if you have questions. ACI’s Sustaining and Organizational Members receive detailed corporate listings; ACI’s Student, Young Professional and Individual Members receive personal listings.

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Inspired by the Spirit of Concrete Highlights of the convention in St. Louis, MO

T

he “Spirit of Concrete” that motivates the volunteerism on behalf of the Institute was in full effect during the ACI Fall 2008 Convention in St. Louis, MO, November 2-6, 2008. This event attracted 1508 registrants, including 218 students and 130 guests, which ranks as the fourth largest attendance at an ACI convention. Congratulations go out to the members of the ACI Missouri Chapter for their organizing efforts. A significant way that ACI is serving its members debuted in the convention exhibitors’ area as ACI previewed its new eLearning Program. Concrete industry professionals now have the opportunity to participate in ACI training programs any time and earn continuing education units (CEUs) online. This will be ACI’s first truly international educational program. Visit www.acielearning.org for more information. Further highlights of another successful ACI convention included:

OPENING SESSION ACI Past President Anthony E. Fiorato presented the 2008 Hardy Cross Commemorative Lecture. He is a Senior Consultant with CTLGroup in Skokie, IL. Prior to his retirement in 2007, he was the firm’s President and CEO. He is a current member of ACI Committee 318, Structural

Concrete Building Code; the ACI Standards Board; the ACI Board Advisory Committee on ISO TC-71; and the Financial Advisory Committee. Fiorato’s talk focused on how we can benefit from Hardy Cross’ reflections on “intelligent standards versus standardized intelligence.” Standardization is a way to make most engineering work routine, Fiorato said, but it “can never replace the brain that created it.” And nothing can take away from the importance of engineering creativity, he concluded. ACI’s Distinguished Achievement Award went to Oliver (Skip) Dulle Jr., Executive Director of the Concrete Council of St. Louis. He became the Council’s Executive Director in April 1987, and his firm Dulle&Co International has provided management services to the Council since that time. The firm also provides administrative and support services to the Eastern Missouri office of the Missouri/Kansas Chapter of the American Concrete Pavement Association. In addition, the Portland Cement Association’s (PCA) 11th Biennial Bridge Awards were presented at the Opening Session. Susan N. Lane, Manager, Transportation Structures, PCA, recognized the principals of the nine winning projects. Basile Rabbat, Manager, Structural Codes, PCA, was on hand to present the awards. More Concrete international

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Oliver (Skip) Dulle Jr. (right) of the Concrete Council of St. Louis received the ACI Distinguished Achievement Award from ACI President Luis E. García

David Darwin, ACI Past President, thanked the participants of the technical session in his honor organized by Joint ACI-ASCE Committee 408, Development and Splicing of Deformed Bars

ACI’s new eLearning Program was previewed in the convention exhibitors’ area

information on the award winners can be found in the November 2008 issue of CI , pp. 29-32.

SPECIAL HONORS TO DARWIN, SNELL A two-part technical session honored David Darwin, ACI Past President and the Deane E. Ackers Distinguished Professor of Civil, Environmental, and Architectural Engineering and Director of the Structural Engineering and Materials Laboratory at the University of Kansas, Lawrence, KS. Joint ACI-ASCE Committee 408, Development and Splicing of Deformed Bars, sponsored the session, which showcased historical and recent developments in

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areas of research where Darwin has made significant contributions to the practice of reinforced concrete design. Presentation topics covered bond strength and behavior, cracking, durability, corrosion, finite element analysis, and fracture mechanics. Emmanuel K. Attiogbe, BASF Admixtures, and Adolfo Matamoros, University of Kansas, were the session co-moderators. Presenters included Theresa Ahlborn, Michigan Technological University; Javier Balma, Walter P Moore & Associates; JoAnn Browning, University of Kansas; Oan Chul Choi, Soong Sil University; James Cox, Sandia National Laboratories; Rolf Eligehausen, University of Stuttgart; Carl Locke, University of Kansas; Carl Peterson, Wiss, Janney, Elstner Associates, Inc.; Surendra P. Shah, Northwestern University; Michael Thompson, University of Wisconsin-Platteville; W. Jason Weiss, Purdue University; and Paul S. Zia, North Carolina State University. That evening, Darwin’s current and former students gathered for dinner with David and Diane Darwin to express their appreciation for his guidance and teaching, share memories, and renew friendships. Other attendees included Paul Zia, Surendra Shah, Thomas Hsu, Grant Halverson, W. Jason Weiss, Adolfo Matamoros, JoAnn Browning, David Suchorski, and Radha Harsh.

The ACI Missouri Chapter held a dinner in honor of Luke Snell, FACI, Arizona State University. Snell has spent “25 years and counting” as a leading member of the chapter, serving as Chapter Secretary for 17 years during his ten ure at the University of Southern Illinois, Edwardsville . Timothy Vaughan, Co-Chair of the ACI Missouri Chapter Convention Committee, began the evening program by crediting Snell for his exceptional mentoring of students. ACI Vice President Richard D. Stehly reviewed Snell’s service to ACI as Chair of the International Committee and Past Chair of the Educational Activities Committee and the Chapter Activities Committee, which has included helping to organize chapters as well as increase the Institute’s certification activities worldwide. ACI Missouri Chapter members David Richardson, Lawrence Taber, and Mark Luther also paid tribute to Luke and Billie Snell. In closing, ACI Missouri Chapter President Patrick Earney announced that the chapter has established the Luke and Billie Snell Undergraduate Scholarship in recognition of their strong commitment in support of education.

Current and former students of David Darwin gathered on the evening of the technical session in his honor. From left: Heather McLeod, Oan Chul Choi, Guohui Guo, Jason Draper, Emmanuel Idun, Jun Zuo, Will Lindquist, Jiqiu Yuan, Emmanuel Attiogbe, Miriam Beatriz Toledo Subirana, David Darwin, Lien Gong, Bill Clawson, Jeff Smith, Javier Balma, Charles Nmai, Jianxin Ji, Rex Donahey, Mike Tholen, Cynthia Ebert, Matt Senecal, and Shraddhakar Harsh

STUDENT ACTIVITIES ACI Past President Dan Baker addressed the audience at the Student Lunch on the topic of leadership. He began by talking about some of the basic principles he learned working side by side with his grandfather Elmer Baker in his concrete company, such as providing customers with first-class quality work and taking care of your employees. He stressed the value of having a double degree: one from school and one from the trenches—those people often make the best leaders. By jumping in and helping on the work site, trust is built with the workers. “Strategically dive in,” Baker said to learn empathy for your colleagues. A good leader is collaborative, a team

ACI Missouri Chapter members at the dinner for Luke and Billie Snell included (from left): Ron O’Kane, Timothy Vaughan, Luke and Billie Snell, Patrick Earney, Mark Luther, Eric Marlinghaus, David Richardson, Jim Posadny, Jim Curry, Lawrence Taber, and John Harris

ACI MISSOURI CHAPTER CONVENTION COMMITTEE Co-Chairs: Mark Luther and Timothy Vaughan Contractors’ Day: Beverly Garnant Exhibits: Ganesh Thiagarajan and James Van Acker Finance/Fundraising: Jim Posadny Guest Program: Billie Snell Publicity: Joe Garza Social Events: Eric Marlinghaus Student Program: Lawrence Taber and Patrick Earney Technical Sessions: D.J. Belarbi and Vellore Gopallaratnam Treasurer: John Harris


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CONVENTION SPONSORS The ACI Missouri Chapter wishes to thank all the organizations for their donations that helped make the ACI Fall 2008 Convention a success: Mississippi River: Baker Concrete Construction, Inc.; Continental Cement Company; Holcim (US), Inc.; and Vee-Jay Cement Contracting Company. Missouri River: Center for Transportation Infrastructure and Safety, and Lafarge. Illinois River: ACI Missouri Chapter, The Euclid Chemical Co., and Sika Corp. Meramec River: BASF Construction Chemicals, LLC; Buzzi Unicem; Ceco Concrete Construction; MC Industrial; and The Korte Company. Kaskaskia River: ACI Arizona Chapter; ACI Greater Miami Valley Chapter; ACI Kansas Chapter; ACI Las Vegas Chapter; ACI Pittsburgh Area Chapter; Ahal Contracting Company, Inc.; Ash Grove Cement Company; Breckenridge Material Company; C.I.M. Partons; Concrete Council; Decorative Concrete Supply; Headwaters Resources; Lehigh Cement Company; Quality Testing & Engineering, Inc.; and SCI Engineering, Inc. Black River: Accurate Scale Company; ACI Arkansas Chapter; ACI Florida Suncoast Chapter; ACI Georgia Chapter; ACI Illinois Chapter; ACI New Jersey Chapter; ACI New Mexico Chapter; ACI Ontario Chapter; ACI Rocky Mountain Chapter; ACI San Antonio Chapter; ACI Southern California Chapter; ACI Western Michigan Chapter; Big River Industries; Buildex, Inc.; Century Concrete; Concrete Company of Springfield; Five Star Ready Mix Concrete; Fordyce Concrete; Hunt Martin Materials; Illinois Cement; Independent Concrete Pipe Company; Instron; J.H. Berra Paving; Kienstra Enterprises; L.G.M. Engineers; Landvatter Ready Mix; Monarch Cement Company; Raineri Building Materials; Luke M. Snell; Tarlton; and TXI Expanded Shale & Clay. Babbling Brook: ACI Los Angeles Chapter Convention Committee; Brundage Bone Concrete Pumping; Cimarron Wholesale; Concrete Promotional Group; Kansas RMCA and Aggregate Producers; L.G. Everist, Inc.; Linn State Technical College; Midwest Concrete Industry Board; MO/KS ACPA; Jim Posadny; SEMO Ready Mix; TK Products, Division of Sierra Corp.; and Virginia Lab Supply.

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player, and a team builder. He ended by stressing the importance of being considerate to everyone when climbing the ladder of success. “Careful you don’t step on any fingers on the rungs below on your way up,” Baker concluded. The work of up-and-coming leaders in concrete technology was showcased in the technical session on “ACI Student Fellowships and Young Member Initiatives.” ACI Student Fellowship recipients Joseph Clendenen, Andrew Coughlin, Stephan Durham, Lisa Feldman, Remy Lequesne, Tyler Ley, Kyle Riding, and Jeffery Volz reviewed their research projects. Tyler Ley, Assistant Professor, Oklahoma State University, began his presentation by thanking ACI for the connections and mentoring possibilities it offered him. His research on the physical and chemical characteristics of the shell of air-entrained bubbles in cement paste was inspired by one of Ken Hover’s talks at a Student Lunch. Ley’s experimental work involved taking microphotos of the bubbles in bleed water every 5 minutes during hydration. From his findings, it appears that a shell is created around a bubble when using an air-entraining admixture and damaged hydration shells can repair themselves.

STUDENT COMPETITION Twenty-two teams from 17 universities entered the 2008 Concrete Cylinder Competition. The top overall finishers were:  First place: Pontificia Universidad Catolica de Chile, students Pierre Esselinck and Pierre Fabre (Carlos Videla, Advisor);  Second place: University of Utah, students Michael Gibbons, Tim Garfield, Brock Loomis, Rachel Smith, and Nathan Jones (Paul Tikalsky, Advisor); and  Third place: Universidad Autonoma de Nuevo Leon, students Ignacio Lozano-Perez, Dario Adrian AguilarRodriguez, Aranely Esmeralda-Ortiz-Castellanos, and Victor Alonso Alvarez de los Santos (Alejandro Duran-Herrera, Advisor). Awards were also given in several other competition categories. The first place team in Lowest Cost was from Purdue University, with students Michael Dettloff, Ross Wagner, Jonathon Chin, Marc Parker, and Graham Bennett (W. Jason Weiss, Advisor). Pontificia Universidad Catolica de Chile students Pierre Esselinck and Pierre Fabre (Carlos Videla, Advisor) achieved first place in the Target Density category. The University of Utah team of Crystal Clendennen, Enoch Eskelson, Stephan Woll, Amanda Gilliland, and Brett Raddon (Paul Tikalsky, Advisor) had the best prediction of Target Strength. First place in Highest Cementitious Efficiency went to Purdue University students Michael Dettloff, Ross Wagner, Jonathon Chin, Marc Parker, and Graham Bennett (W. Jason Weiss, Advisor). The complete list of winning teams in the 2008 Concrete

Cylinder Competition can be found at www.students.concrete.org. Before the start of the day’s competition, Peter Hughes, one of the winners in the ACI 2008 Concrete Projects Competition, presented his paper on “An Investigation of MacroSynthetic Fiber-Reinforced Concrete.” The paper, which garnered Hughes second place, was part of his dissertation to fulfill requirements for his BSc in building surveying from the University of Central Lancashire, UK. Hughes discussed the use of macro-synthetic fiber-reinforced concrete in revetment units that are part of the Blackpool, UK, central area coast protection program. He also was a regional winner in the Institution of Civil Engineers Graduate and Student Papers Competition for 2008.

standards. However, as ACI and ASTM International both write construction testing standards on full structures, the proper domain of similar test methods and specifications are called into question.



The E-Membership Pilot Program has not met expectations and has been terminated. Individuals currently enrolled in the program will be “grandfathered” and allowed to maintain their e-membership at

SIGNIFICANT BOARD ACTIONS The ACI Board of Direction approved the following motions at the ACI Fall 2008 Convention:  Membership categories and service on committees have been clarified. Now, all ACI members (Student, Young Professional, Individual, Organizational-Sustaining representatives, Honorary, and Fellow) will be provided the opportunity to serve as Associate Members on three technical committees, three educational committees, and three certification committees.  A Board-level ACI Coordinating Task Group is to be formed with ASTM International to coordinate the writing of concrete-related specifications, resolve potential conflicts, and identify opportunities for collaboration. The Technical Activities Committee is authorized to appoint the ACI representatives of the Task Group. ACI staff attended a meeting with ASTM International in September 2008, where responsibility for standards was discussed. ACI has a Memorandum of Understanding with ASTM International (1936) on a division of responsibility for

Concrete Legacy Society “ACI has enabled me to remain technically competent, and ACI continues to expose me to all the happenings and new developments in our industry. More importantly, though, I am motivated to give back to this industry that has shown such support for me throughout my career.” – Dick Stehly, Principal, American Eng ineering Testing, Inc.; 2008-2010 ACI Vice President; and member of the Concrete Legacy Society

The Concrete Legacy Society is a special group of individuals, who are passionate about the concrete industry, and have included ACI or the ACI Foundation in their estate plans, helping to ensure that future generations will have access to continued advancements in concrete knowledge.

www.ACIFoundation.org – 248-848-3778 Concrete international

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ACI FALL 2008 CONVENTION EXHIBITORS BASF Construction Chemicals, LLC Big River Industries Buckeye Building Fibers, LLC Butterfield Color CON-CURE Corp. Decon USA, Inc. Electro TechCP Engius ERICO The Euclid Chemical Co. Flatwork Technologies FORTA Corp. Fred Weber, Inc.—Iron Mountain Trap Rock General Resource Technology Germann Instruments, Inc. Grace Construction Products Greenstreak Group, Inc. Headwaters Resources, Inc. Holcim (US), Inc. ICI Rheocenter Kryton International, Inc. Lafarge Maccaferri Group, Inc. Missouri University of Science and Technology NEES Consortium, Inc. Octaform Systems, Inc. Omya Canada, Inc. Outokumpu Stainless Proceq USA, Inc. QuakeWrap, Inc. Sika Corp.

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the lower rate, provided their membership does not lapse. The International Committee’s (IC) subcommittee on Membership is discharged. The IC subcommittee on Certification will be moved to the Certification Programs Committee and be allowed to continue with their mission. The IC subcommittees on Publications and Web site will be merged with the IC subcommittee on Partnerships and be renamed the International Partners and Publications subcommittee, reporting to the IC and their mission statement will be rewritten to include the publication aspects of the new subcommittee. ACI will take over from CANMET sponsorship of the Ninth Superplasticizers Conference and the 10th MARCH 2009






Conference on Advances in Concrete Technology, to be held in Seville, Spain, during October 2009, without financial impact. ACI is to be a cosponsor for the international exhibition and research program on the work of Pier Luigi Ner vi, without financial obligation. ACI received a request from the ACI Italy Chapter to cosponsor an international exhibition and a research program on the work of Pier Luigi Nervi, ACI Honorary Member, 1969. The exhibition will first tour in Europe, starting in 2009. After that, the exhibition will be shown in the U.S. and Canada, initiating at the Museum of Modern Art in New York, NY. The procedures for the “Organization and Operation of the Committee on Awards for Papers” have been revised and a policy has been developed to honor ACI’s distinguished deceased members.

SPECIAL EVENTS The International Lunch featured Konrad Bergmeister, Professor, Universität für Bodenkultur Wein, Vienna, Austria, who spoke on “Repair and Maintenance of Aging RC Bridges.” He stressed the importance of integrating work-site planning with repair and maintenance activities. Bergmeister’s message was that a cooperative and synergistic approach creates a better working environment that can reduce repair time and costs. “Innovation in the Construction Industry” was the theme of the Contractors’ Day Lunch with Jeff Steinhart, Vice President of Engineering, Anheuser-Busch (A-B). The brewing company has been an innovator in its field, such as being the first to pasteurize its beer and use refrigerated rail cars. Its commitment to innovation carries on to its civil and structural engineering practices. For example, A-B views its concrete floors as an asset instead of an expense and follows ACI specifications for their construction. Lower shrinkage mixtures are used, along with mandatory wet cure and polyurea sealants for joint edge protection. They also require Class 5 floor finishes and concrete is polished to improve the appearance of existing floors, providing a low-cost alternative to replacement. The Oktoberfest-themed Concrete Mixer was another example of the ACI Missouri Chapter’s great attention to the details in planning the convention. The hotel ballroom was transformed into a replica of a German biergarten and a good time was enjoyed by all.

DOWN THE TRAIL TO SAN ANTONE The ACI Spring 2009 Convention is taking place March 15-19, at the Marriott Rivercenter in San Antonio, TX. Of particular interest is a LEED for New Construction and Major Renovations Technical Review Workshop, scheduled for March 14. Go to www.concrete.org/Convention/Spring-Convention/ Front.asp for more information.

Highlights of the ACI Fall 2008 Convention OPENING SESSION

ACI Missouri Chapter members (from left) Mark Luther, Patrick Earney, and Timothy Vaughan received certificates of appreciation for the chapter’s convention organizing efforts from ACI President Luis E. García

ACI President Luis E. García (left) with Claudia Pulido, a winner of the PCA 11th Biennial Bridge Awards

ACI Past President Anthony E. Fiorato presented the 2008 Hardy Cross Commemorative Lecture

Judy Hukey, ACI Book Drive organizer, gave an update of the program. After the fall convention, approximately 300 books were donated to the Winfield, MO, school district library damaged by flooding


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STUDENT ACTIVITIES

At the Concrete Cylinder Competition, from left: Rita Madison, Arkansas Ready Mixed Concrete Association; Frances Griffith, University of Arkansas; and students Anna McGraw and Alex Lueders Concrete Cylinder Competition at the Fall 2008 Convention

Peter Hughes, University of Central Lancashire, UK, presented his paper on “An Investigation of MacroSynthetic Fiber-Reinforced Concrete”

ACI Missouri Chapter President Patrick Earney handed out prizes to students who correctly answered his questions on concrete technology

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Universidad Autonoma de Nuevo Leon finished third overall

Pontificia Universidad Catolica de Chile took first place overall in the Concrete Cylinder Competition. Lawrence Taber (center), Chair of ACI Committee E801, Student Activities, presented the awards

David Bey accepted the awards for the University of Utah

ACI Past President Dan Baker spoke about leadership to the Student Lunch audience

Lawrence Taber gave out Kestrel 4300 hand-held wind meters to winners of a raffle drawing


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AROUND THE CONVENTION

Anheuser-Busch representatives Jerry Eyink (left), Group Director, Project Management; and Jeff Steinhart, Vice President of Engineering, discussed “Innovation in the Construction Industry” at the Contractors’ Day Lunch

At the International Lunch, from left: Luke Snell, Chair, International Committee; Dave Darwin, ACI Past President; Florian Barth, ACI Vice President; Konrad Bergmeister, International Lunch speaker; Mario Rodriguez, Chair, International Conferences/Conventions Subcommittee; and H.S. Lew, International Conferences/Conventions Subcommittee member

At the International Partners meeting

Previewing the Spring 2009 Convention at the ACI San Antonio Chapter desk

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CONCRETE MIXER

The theme of the Concrete Mixer was Oktoberfest

Mark Luther (right) with Larry Hallar, leader of Two Star Final, the combo that played Bavarian music during the event


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PRESIDENT’S RECEPTION

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UNDERLAYMENT PROVIDES HARD, LONG-LASTING SURFACE Levelrock® brand 4500 NXG™ floor underlayment features outstanding strength and innovative selfsealing technology. It provides a smooth, hard, longwearing surface at thicknesses from featheredge to 2 in. (50 mm). It offers compressive strengths of up to 5500 psi (38 MPa) and exceptional surface hardness to resist marks and indentation from traffic. Quick application and setting times permit the resumption of traffic within hours of installation. Its built-in sealer allows floor coverings to be installed without priming or sealing the surface, saving time and money. This high-performance formula is designed for interior use in a wide variety of commercial, institutional, and rehabilitation projects. —USG Corp. CIRCLE 51

SINGLE TOOL INCORPORATES FOUR FUNCTIONS The Level Best2 incorporates two opposing level bubbles, a perfect 90-degree angle, and a ruler, creating a single tool that can be used to level, plumb, square, and measure all kinds of projects. It’s dual sided so it can be turned over and applied to all four corners of a foundation, footing, or form, and the pencil slot makes it easy to create accurate markings. The stair tread and stair rise minimum and maximum measurements make measuring and setting concrete or masonry steps simple and exact. It’s great for use on flatwork forms, foundations, stairs, countertops, retaining walls, and footings. It comes in three different sizes: 16 x 24 in. (400 x 600 mm), 12 x 12 in. (300 x 300 mm), and 6 x 6 in. (150 x 150 mm). — SLK Development Group, LLC CIRCLE 52

COATING PROTECTS CONCRETE Klear Gard™ WB is a water-based clear acrylic emulsion formulated to be used as a concrete sealer and dust proofer. It’s resistant to most industrial chemicals and tough enough to withstand heavy traffic. It’s nontoxic, nonflammable, and easily cleaned. It features excellent intercoat adhesion so surfaces can easily be recoated. It can be applied by spray, brush, or roller. Klassic Kolor dyes and Kolor Packs can be added to create more than 20 color options. —Contract Packaging, Inc. CIRCLE 53 Click on the Free Product Information link at www.concreteinternational.com for more information or to be directed to the companies’ Web sites. You can also obtain more information by using our reader service inquiry system and circling the appropriate number for the items of your choice. Concrete international

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EXCAVATOR DESIGNED FOR OPERATOR COMFORT The Caterpillar® 345D L hydraulic excavator has replaced the 345C L model. It builds on the strengths of its predecessor while incorporating new designs that enhance performance and durability. To conserve fuel during light-duty work, the hydraulic and engine control systems now include a power management feature. The operator has the flexibility to select from alternative engine and hydraulic power settings without sacrificing breakout force or lift capacity. It also features undercarriage improvement, a heavier counterweight for greater stability and lifting performance, and an electric regeneration circuit to boost hydraulic efficiency and reliability. The cab is spacious, quiet, and comfortable with good ventilation, ergonomic controls, and an easy-to-read monitor that displays information in 27 languages. For extra comfort and productivity, a high-back, heated, air-suspension seat is now standard. An optional rear-view camera and Work Area Vision System enhance visibility, productivity, and job site safety. —Caterpillar Inc. CIRCLE 54

ANCHOR RECEIVES ICC-ES EVALUATION REPORT The Titen HD® screw anchor provides a high-strength connection for concrete and masonry, and it’s now been tested for use in both cracked and uncracked concrete—meeting the requirements of the 2006 International Building Code for post-installed anchors (see ICC-ES evaluation report ESR-2713). The anchor has been tested in accordance with AC193 and has been shown to provide outstanding performance in cracked and uncracked concrete under both static and seismic loading conditions. Its self-undercutting, nonexpansion characteristics make it ideal for structural applications, even at reduced edge distances. The threaded design requires less installation torque, allowing quick and easy installation. It installs with standard-size drill bits and is removable. — Simpson Strong-Tie CIRCLE 55

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Information on the items reported in “Products & Practice” is furnished by the product manufacturers, suppliers, or developers who are responsible for the accuracy of the information. Also, the descriptions of these items do not represent endorsement by this magazine, by the American Concrete Institute, or any of its staf f. They are published here simply as a service to our readers.

LIFTING SYSTEM ALLOWS COMPLETION OF COMPLEX BRIDGE Construction of the Third Millennium Bridge in Zaragoza, Spain, involved a unique feat of hydraulic engineering. With only 3 days to complete the job, the concrete arch had to be moved and the cantilevers had to be pushed apart to make space in the crown of the arch for the final concrete casting. The crucial job of jacking apart the crown of the bowstring arch was done with an Enerpac synchronous hydraulic lift system with six double-acting lock nut cylinders, each with a lifting capacity of 2000 tonnes (2200 tons). All six jacks were monitored by a single programmable logic controller. In addition to crown jacking, the lift system was also used to provide hydraulic jacking to tension the cables and raise the deck to its final position. The custom-designed synchronous lift system was engineered to push apart and hold the two parts on top of the arch, leaving the arch totally unshored. This precision operation involved an electronic programmable system that synchronized three pairs of cylinders to within 0.5 mm (0.02 in.) between leading and trailing points of the jacks. The system imposed a load of slightly more than 12,000 tonnes (13,200 tons) on the arch to permit the jacking and closing operation 36 m (118 ft) above the deck of the bridge. Computer-based synchronization was carried out with software developed to take account of roll as the arch opened while controlling individual loads per cylinder as well as pairs of cylinders. The system was designed with automatic failsafe functions to halt the operation and hold the load if synchronization was interrupted. — Enerpac CIRCLE 56

ADHESIVE MEETS STRINGENT CODES AC100+Gold is a two-component, high-strength structural adhesive anchoring system that meets the new, more stringent criteria for strength design of concrete anchors in the International Building Code. It can be used to bond threaded rod and reinforcing bar into solid concrete and masonry base materials. It can also be used to anchor into hollow masonry materials using screen tubes. It cures fast and has superior dispensing speed. This low-odor formula contains no styrene, methyl-methacrylate, or VOCs. It works well in damp and wet holes and is ideal for cold weather applications. — Powers Fasteners, Inc. CIRCLE 57 Concrete international

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REINFORCEMENT MANUFACTURER LAUNCHES REDESIGNED SITE Saint-Gobain Technical Fabrics, makers of FibaTape®, FibaCrete®, and other reinforcement fabrics, has launched its redesigned Web site, www.sgtf.com . This user-friendly site is easy to navigate for new and experienced visitors. Easy search functions allow users to search by keyword, brand name, industry, or technology. Downloadable product sell sheets give users quick access to detailed product information. The employment section lists job opportunities, and the news and press release section allows users to stay up to date. The contact section allows users to obtain more product information and product quotes.

NEW FROM CSDA To establish proper industry standards and ensure the highest levels of safety and workmanship, the Concrete Sawing & Drilling Association (CSDA) has published Specification CSDA-PC-113, Polishing Concrete. It covers the proper codes and standards to be applied on polishing projects, as well as the needed prerequisites for the work, polishing setup procedures, and equipment operation. As a result of the Americans with Disabilities Act (ADA) of 1990, the U.S. government has issued a series of guidelines and regulations to establish a standard level of accessibility for people with disabilities. The guidelines are to be followed during the design, construction, and alteration of buildings. Best Practice CSDA-BP-005, Diamond Cutting Tools for ADA, provides a quick overview of the ADA standard and outlines the types of concrete cutting tools that can be employed to perform the tasks necessary to be in compliance with the standard. Best Practice CSDA-BP-006, Hydraulic Concrete Cutting Equipment , is intended to provide information on general maintenance, differing design options, and troubleshooting guides. The information can help cutting contractors obtain increased levels of efficiency and lifespan from their equipment, as well as ensuring against potential faults and hazards. A troubleshooting guide provides solutions to several possible problems that can occur when working with this type of equipment. These documents, along with CSDA’s other Best Practices and Specifications, are available to download for free. Visit www.csda.org and click on the “Standards, Specs & Best Practices” link on the right-hand side of the page.

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Shotcrete AIRPLACO EQUIPMENT CO. The PumpMaster™ PG-25 grout pump improves on previous models. It includes a new 3 in. (75 mm) discharge assembly that has been refined for the use of pea rock, allowing smoother pumping. It features 50 ft (15 m) of vertical and 200 ft (61 m) of horizontal pumping capacity. The 5 ft3 (0.14 m3 ) hopper and 5 in. (125 mm) HARD-CHROME™ material cylinder are capable of outputting up to 6 yd3 (4.6 m3 ) per hour. It has a hydraulic drive train and offers more horsepower than previous models. It can also be used for masonry block fill, ICF walls, patio and sidewalk pumping, mudjacking, and pressure grouting. — Airplaco Equipment Co. CIRCLE 58

SPEC MIX, INC. The patent-pending SPEC MIX® PA4000 Power Auger Delivery System is specifically designed for delivering all SPEC MIX dry preblended products to mixers. It gives contractors and precast manufacturers the ability to maximize their efficiency, productivity, and safety by increasing the mobility and versatility of their material mixing station. This low-profile compact unit holds up to five 3000 lb (1360 kg) bulk bags, reducing job site waste a nd clean-up costs. Material can easily be loaded into the PA4000 from ground level with a heavyduty skid steer. With a footprint measuring 8 ft x 8 ft 4 in. (2.4 x 2.7 m), it’s ideal for interior and exterior jobs with height and weight restrictions and for crews constantly on the move. — SPEC MIX, Inc. CIRCLE 59

Click on the Free Product Information link at www.concreteinternational.com for more information or to be directed to the companies’ Web sites. You can also obtain more information by using our reader service inquiry system and circling the appropriate number for the items of your choice. Concrete international

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SIKA CORP. Sigunit® L72 AF is a new generation, high-performance, alkali-free liquid set accelerator for wet and dry shotcrete applications. Its ability to produce very high early strength shotcrete results in faster construction and a safer working environment for construction workers in tunnels. It offers a distinct reduction in rebound and dust and an improved bond of shotcrete to rock and concrete, facilitating overhead spraying. It also avoids pollution of groundwater by leaching of alkalis. It meets the requirements of ASTM C1141 as a quick-setting accelerator and can be used in shotcrete utilized for initial support and final lining in tunnels and rock and slope stabilization. It’s compatible with other Sika admixtures used ® for shotcrete such as Sikatard 930 (hydration control admixture) and high-range water reducing admixtures from the Sika Viscocrete® and Sikament® series. — Sika Corp. CIRCLE 60

BEKAERT CORP. Dramix® steel fibers are an easy alternative for reinforcing shotcrete. These high-tensile-strength steel fibers offer a significant reduction in cost and a greater speed of construction. Steel fiber-reinforced shotcrete applications can follow the contours of the ground, providing a consistent thickness and reducing material volume. The fibers also give resistance to tensile stresses at any point in the shotcrete layer. — Bekaert Corp. CIRCLE 61

MULTIQUIP Mayco’s LS concrete pump series consists of the LS300, the mid-range LS400 and LS500, and the heavy-duty LS600. All of the pumps feature an innovative digital control panel that provides diagnostic readouts in English or Spanish, allowing the operator to quickly determine the current status and assist in troubleshooting. Other standard features include hydraulic surge brakes, true reverse shuttle tube pumping, and an exclusive full-flow shuttle-tube concrete valve. The LS300 is designed to handle larger aggregate up to 1-1/2 in. (38 mm). The LS400 and LS500 are capable of handling low cement/sand mixtures. The LS600 is ideal for low-slump concrete, tough rocky mixtures, hard-to-reach areas, large slabs, and long-distance applications. The pumps are ideal for a variety of shotcrete, masonry, flatwork, block fill, and specialty applications. — Multiqiup CIRCLE 62

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REED The C50SS Model Shotcrete Pump is specifically designed for extremely long-distance and high-volume shotcrete applications. It’s powered by the combination of a 164 kW (220 HP) Cummins diesel engine and a 180cc (11 in.3 ) main hydraulic pump. This extremely high-performance machine offers a maximum output of 41 m3 (54 yd3 ) per hour and the option of dual nozzling. This pump packs all of its horsepower and pressure into a relatively small package, measuring only 4.67 m (15.3 ft) in length. — REED CIRCLE 63

KING PACKAGED MATERIALS CO. King MS-D1 Shotcrete (dry mix) and MS-W1 Shotcrete (wet mix) are prepackaged, air-entrained shotcrete mixtures reinforced with micro-synthetic fibers that have greatly enhanced shooting characteristics and physical properties. The entrained air provides superior resistance to salt scaling and damage from freezing-and-thawing cycles. The mixtures offer significantly reduced rebound, resulting in less material used. They are able to build greater thicknesses in a single pass in both vertical and overhead applications. They offer excellent adhesive and cohesive plastic properties, low shrinkage and permeability, and improved resistance to water washout and sulfate attack. MS-D1 Shotcrete is also available with optional accelerators and a high cement content for applications that require fast set times and rapid strength gain. — King Packaged Materials Co. CIRCLE 64


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MASTER BUILDERS CELEBRATES 100 YEARS BASF Construction Chemicals, LLC, is celebrating the 100th anniversary of its Master Builders brand. BASF will be highlighting the people, projects, and products that have made the brand a success at www.100yearsofchemistry.com . Founded in 1909 by S.W. Flesheim, the Master Builders brand has been a fixture in the construction market since the introduction of its first product, a cement/iron floor topping mixture broadcast on top of freshly placed concrete that dramatically improved the wear resistance and appearance of floors. That same innovative thinking has continued through the decades and was used in the development of some of the first chemical admixtures, giving producers the ability to make uniform, predictable concrete. Over the past century, Master Builders products have been used in many notable projects such as the Hoover Dam, Sydney Opera House, Panama Canal, and Sears Tower, and the people behind the brand have garnered more than 100 patents for their technical achievements. Today the brand represents more than 150 products and continues to add to its portfolio as new needs emerge. HYCRETE MARKS 100TH PROJECT Hycrete Inc. has completed its 100th project with Hycrete Element™, an environmentally friendly integral waterproofing admixture. Developed over the span of nearly 40 years, it was first used in 2003 for a precast barrier project. The company began work on its 100th project, a Seattle, WA, parking garage, in the fall of 2008. An estimated 5 million ft2 (465,000 m2 ) of concrete has been treated to date. The admixture is certified Cradle-to-Cradle by McDonough Braungart Design Chemistry, LLC. It’s pa rt of the larger Hycrete IntegraTek Waterproofing System, which combines service with the admixture to waterproof entire structures and eliminates the need for external membranes. VETERANS PROGRAM ASSISTS TRANSITION TO NEW CAREERS Engrave-A-Crete Inc., a manufacturer and distributor of decorative concrete engraving equipment, is offering a special program to help military veterans transition to new careers. Throughout 2009, members of the armed services who’ve been on active duty since 2001 will qualify for a 10% discount on any of Engrave-A-

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Crete’s start-up business packages. They will also receive a 50% discount on attendance at Engrave-A-Crete’s Discovery and Training Seminars. For more information on this program, call (800) 8842114 or visit www.engrave-a-crete.com. AGREEMENT COVERS DISTRIBUTION RIGHTS IN CANADA AND EUROPE HC Bridge Company, LLC, a firm specializing in the development of hybrid-composite structural alternatives that can be used for accelerated bridge construction and offer a long service life, recently entered into a licensing agreement with Innovative Infrastructure Solutions Canada Ltd. (IISC). This partnership will allow IISC exclusive rights to sell, distribute, and fabricate HC Bridge Company’s Hybrid Composite Beam (HCB) technology, as well as other hybrid composite bridge components to be developed in the future, in Canada, excluding Maritime Provinces, and all 27 European Union member statess. The collective goal is to provide infrastructure owners with a prefabricated advanced composite bridge system. The HCB represents a unique application of fiberreinforced polymer (FRP) and composite bridge technology in that it incorporates several different materials in an embodiment of a beam that exploits and optimizes the inherent qualities of each material. It comprises an FRP shell, compression reinforcement, and tension reinforcement. The compression reinforcement consists of self-consolidating concrete that’s pumped into an arch conduit within the beam shell. The tension reinforcement consists of high-strength steel prestressing strands that run along the bottom flanges of the beam shell. All of this is encapsulated in an FRP shell to protect the beam from corrosion and provide additional structural capacity. GRACE INVESTS IN GREEN MATERIALS COMPANY W.R. Grace & Co. has completed a strategic investment in CERATECH, Inc., a company that’s developed green admixture technologies for producing high-strength, fast-setting concrete primarily using fly ash. The technology uniquely enables the production of environmentally friendly, high-performance concrete. Under terms of the investment, Grace also has exclusive rights to market CERATECH products and technology in the manufactured concrete market.

See the events calendar at www.concreteinternational.com for more listings.

2009 MARCH 15-18 American Concrete Pipe Association Annual Meeting, Naples, FL— contact Matthew Childs, telephone: (972) 506-7216; e-mail: mchilds@ concrete-pipe.org; Web site: www.concrete-pipe.org.

15-18 National Ready Mixed Concrete Association Annual Convention, Orlando, FL—contact Jennifer Leonard, telephone: (240) 485-1156; e-mail: [email protected]; Web site: www.nrmca.org.

15-19 International Foundation Congress & Equipment Expo ’09, Lake Buena Vista, FL—contact Jan Hall, telephone: (214) 343-2091; e-mail: jhall@adsc-iafd. com; Web site: www.ifcee09.org.

22-26 Corrosion 2009, Atlanta, GA— contact NACE International, telephone: (800) 797-6223 or (281) 228-6200; fax: (281) 228-6300; e-mail: firstservice@ nace.org; Web site: www.nace.org.

27-30 Architectural Precast Association Annual Convention, Riverside, CA— contact APA, telephone: (239)

454-6989; fax: (239) 454-6787; e-mail: [email protected]; Web site: www.archprecast.org.

APRIL 22-24 National Conference on Preservation, Repair, and Rehabilitation of Concrete Pavements, St. Louis, MO— contact Shiraz Tayabji, telephone: (410) 997-9020; fax: (410) 997-9028; e-mail: [email protected]; Web site: www.fhwa.dot.gov/pavement/ concrete/2009CPTPconf.cfm.

MAY 5-9 The Masonry Society 2009 Spring Meetings, Herndon, VA—contact TMS, telephone: (303) 939-9700; fax: (303) 541-9215; e-mail: [email protected]; Web site: www.masonrysociety.org.

25-27

2009 Precast/Prestressed Concrete Institute Committee Days, Chicago, IL—contact Danielle Lang, telephone: (312) 360-3212; e-mail: [email protected]; Web site: www.pci.org.

International Conference on Concrete Pavement Design, Construction, and Rehabilitation, Xi’an, China—contact Mark Snyder, telephone: (412) 221-8450; e-mail: [email protected]; Web site: www.concretepavements. org.

23-24

27-30

International Concrete Repair Institute 2009 Spring Convention , Minneapolis, MN—contact Caren Giles, telephone: (248) 848-3809; e-mail: [email protected]; Web site: www.icri.org.

3rd International Conference on Construction Engineering and Management/6th International Conference on Construction Project Management, Jeju, Korea—contact the secretariat, telephone: +82-2-5666067; fax: +82-2-566-6087; e-mail; [email protected]; Web site: www.iccem-iccpm.org.

23-25

APRIL/MAY 30-2 2009 Structures Congress, Austin, TX—contact ASCE, telephone: (800) 548-2723; e-mail: registrations@asce.

UPCOMING ACI CONVENTIONS The following is a list of scheduled ACI conventions: 2009 — March 15-19, Marriott Rivercenter, San Antonio, TX. 2009 — November 8-12, Marriott New Orleans, New

Orleans, LA.

2010 — March 21-25, Sheraton, Chicago, IL. 2010 — October 24-28, Westin &

org; Web site: content.asce.org/ conferences/structures2009/.

Convention Center, Pittsburgh, PA.

For additional information, contact: Event Services, ACI, P.O. Box 9094 Farmington Hills, MI 48333-9094 telephone: (248) 848-3795 • e-mail: [email protected]

JUNE 14-16 1st International Conference on Civil Engineering Towards a Better Environment, Coimbra, Portugal— contact CI Premier, telephone: +6567332922; fax: +65-62353530; e-mail: [email protected]; Web site: www.cipremier.com.

16-19 CONSTRUCT2009, Indianapolis, IN—contact Hanley Wood, telephone: (972) 819-7601; fax: (972) 536-6364; e-mail: [email protected]; Web site: www.constructshow.com. Concrete international

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The following ACI draft standards are open for public discussion. They are being processed through ACI’s ANSIapproved standardization procedures and are not yet official ACI standards. To see a summary of all ACI draft standards in process or recently completed within the past 3 months, please visit www.discussion.concrete.org.

Document number

Title

Open for discussion

Discussion closes

346

Specification for Cast-in-Place Concrete Pipe

3/1/2009

4/17/2009

423.X

Test Method for Bleed Stability of Cementitious Post-Tensioning Tendon Grout

2/1/2009

3/17/2009

ITG-5.2

Design of a Special Unbonded Post-Tensioned Precast Shear Wall Satisfying ACI ITG-5.1 Requirements

3/1/2009

4/17/2009

PROPOSED STANDARD “SPECIFICATION FOR CAST-IN-PLACE CONCRETE PIPE (346)” The ACI Technical Activities Committee (TAC) approved processing the subject document through the ACI Standardization Procedure in July 2008, as did the ACI Standards Board in January 2009. Therefore, this new document is open for public discussion from March 1, 2009, until April 17, 2009. The document appears on the ACI Web site, www.discussion.concrete.org. Pertinent discussion will be available on ACI’s Web site and announced in a future issue of Concrete International if received no later than April 17, 2009. Comments should be e-mailed to [email protected] or mailed to Jessie L. Bournay, Supervisor of Technical Documents, American Concrete Institute, 38800 Country Club Drive, Farmington Hills, MI 48331.

PROPOSED STANDARD “DESIGN OF A SPECIAL UNBONDED POST-TENSIONED PRECAST SHEAR WALL SATISFYING ACI ITG-5.1 REQUIREMENTS (ITG-5.2)” The ACI Technical Activities Committee (TAC) approved processing the subject document through the ACI Standardization Procedure in July 2008, as did the ACI Standards Board in January 2009. Therefore, this new document is open for public discussion from March 1, 2009, until April 17, 2009. The document appears on the ACI Web site, www.discussion.concrete.org. Pertinent discussion will be available on ACI’s Web site and announced in a future issue of Concrete International if received no later than April 17, 2009. Comments should be e-mailed to [email protected] or mailed to Jessie L. Bournay, Supervisor of Technical Documents, American Concrete Institute, 38800 Country Club Drive, Farmington Hills, MI 48331.

Upcoming Themes April 2009—Repair & Renovation May 2009—Durability June 2009—Formwork For advertising details, contact Jeff Rhodes • Phone (410) 584-8487 • e-mail: [email protected]

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PROFESSIONAL SERVICES

Classified Rates for Concrete International : $100 for first 50 words and $2 for each additional word over 50.

Online Classified ad deadlines: Ads post on the 1st and 15th of every month and will run for one month. If you want your classified ad to appear on the first of the month, contracts and text are due on the 25th of the month prior to appearance; if you want your ad to appear on the 15th of the month, contracts and text are due by the 10th of the month that your ad will appear.

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ENGINEER Exciting opportunity at the American Concrete Institute, headquartered in Farmington Hills, Michigan. Individual with civil engineering degree and 5+ years of experience in engineering materials related to concrete. Concrete construction experience preferred. You’ll respond to technical inquiries, assist in developing and editing technical documents, and interact with technical committees that produce ACI 318 and related documents. Resume and salary requirements to:

CI ADVERTISING For more information, contact: Jeff Rhodes, Sales Manager Network Media Partners (410) 584-8487 E-mail: [email protected] Chemco Systems ....................................................................................................... 55 Computerease ................................................................................Inside Back Cover Computers & Structures, Inc. .................................................................. Back Cover CTS Cement Mfg. Corp. ............................................................................................ 13 Decon ........................................................................................................................... 1 Elcometer Inspection Equipment ........................................................................... 51 Gerdau Ameristeel ...................................................................................................... 2 Northeast Solite Corporation .................................................................................. 11

Director, Human Resources - ENG P.O. Box 9040 Farmington Hills, MI 48331-9040 E-mail: [email protected]

Outokumpu ................................................................................................................ 33 QuakeWrap, Inc. .......................................................................................................... 6 StructurePoint ............................................................................... Inside Front Cover Xypex Corporation ................................................................................................... 29

ACI’s Career Center ACI’s Online Career Center brings together great job opportunities and great candidates. This job search engine is specifically targeted to the concrete industry. • • • •

Easy online job management Resume searching access Company awareness FREE Student Internships

Don’t miss this unique opportunity to be seen by an exclusive audience of the industry’s best and brightest! Visit www.concrete.org .


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Fabrication of Standees Q.

Figure 1 shows reinforcing bars bent to support the top mat of bars in a thick foundation. I understand that the bar fabricator generally supplies these, but is it feasible to fabricate them on site? If so, are there any instructions or diagrams that can help ironworkers produce them? I assume that because they only support bars, there are no requirements for minimum bend diameter, so the main concern would be fabricating them carefully enough to meet the placing tolerances for the bars that they support. Any information you can give me would be appreciated.

A. standees. The two types of standees (Types 25 and 26) The bar supports you refer to in Fig. 1 are known as

Because standees are only support bars, they can be bent to much tighter radii than allowed for structural bars. One must be careful, however, not to bend them to too tight of a radius or the bars might develop microcracks that cause them to fail under the weight of the bars they are supporting. The fabricator will be bending to normal tolerances of ±1/2 in. (±13 mm), so it’s conceivable that some standees will be up to 1 in. (25 mm) taller than the shortest ones. For thick slabs, this is likely not a problem, but not so for thinner slabs. To ensure tighter tolerances are met, it’s a good idea to detail standees as Type S1 bars (Fig. 3) with

that are normally fabricated from reinforcing bars are shown in Fig. 2. The standee in Fig. 1 is a Type 25. FABRICATION Generally, standees are supplied by the reinforcing steel fabricator. They are considered accessories, however, so fabricators may treat them as extra work or materials and not include them in their contract price. Because they are not considered stirrups or ties, they are typically bent with standard mandrels, rather than smaller stirrup-and-tie mandrels. If the dimension at the top of the standee (dimension D in Fig. 2) is not somewhat larger than the mandrel diameter, the top of the standee will be slightly rounded, rather than flat, and may make it difficult to maintain the supported bar in the desired position. Contractors should therefore request that standees be bent on stirrup mandrels. This will tend to make the leg dimensions (dimensions C and E in Fig. 2) more uniform and minimize the dimension D required to provide a flat support.

Fig. 1: The supports fabricated from reinforcing bar shown in this photo are referred to as standees (Photo courtesy of ColusaNET, Inc. and Rick Kunze)

(a)

(b)

Questions in this column were asked by users of ACI documents and have been answered by ACI staff or by a member or members of ACI technical committees. The answers do not represent the official position of an ACI committee. Only a published committee document represents the formal consensus of the committee and the Institute. We invite comment on any of the questions and answers published in this column. Write to the Editor, Concrete International, 38800 Country Club Drive, Farmington Hills, MI 48331; contact us by fax at (248) 848-3701; or e-mail [email protected].

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Fig. 2: There are two types of standees that are typically produced from reinforcing bar: (a) Type 25; and (b) Type 26 (from Reference 1)

Fig. 3: Standees can also be detailed as Type S1 bars bent in the shop with the feet bent later in the field (from Reference 1)

Fig. 4: When the standees rest on a bottom layer of bars, the length of the feet (dimensions B and F in Fig. 2) should be about 1.5 times the bottom bar spacing so the standees sit solidly across at least two bars (Photo courtesy of ColusaNET, Inc. and Rick

only dimensions B, C, and D called out. That way, the fabricator will automatically bend them as stirrups on a smaller mandrel, and the contractor will be able to bend the feet of the standee using a manually-operated bender or a powered bender on site. Ironworkers will thus be able to control the height dimension to a very precise tolerance. There are a number of commercial manually-operated benders available that can easily bend No. 3 and 4 (No. 10 and 13) bars and bend limited quantities of No. 5 (No. 16) bars. Larger bars must be bent on a powered bender. If a commercial manually-operated bender is not readily available, one can be easily fabricated at a local machine shop. DETAILING There are a few things to keep in mind when detailing standees. If the standee is going to sit on a blinding layer of a footing (a slab directly below the foundation, also called a mud slab or mud mat), or on formwork, the B and F sides should be about the same length as the D dimension. The dimensions shown in Table 1 generally work well. As the standees get taller, B and F should perhaps be a bit longer—it’s a matter of judgment. If the standees are going to sit on the bottom reinforcing bars of a footing or slab, however, B and F should be 1.5 times the spacing of the bars they are sitting on, so they can sit solidly across at least two bars as shown in Fig. 4. Likewise, D should be 1.5 times the spacing of the top mat. WHICH TYPE? There are fundamental differences between Type 25 and 26 standees. Fabricators like Type 25 because they are easier to bend. Type 26 standees, however, have to be lifted and turned after the first bend and before the last bend. Also, the legs for Type 26 standees are vertical, which makes them stronger and less likely to collapse. Type 25 standees have the advantage of being adjustable (the height can be changed simply by spreading the

Kunze)

TABLE 1: SUGGESTED B AND F

DIMENSION FOR STANDEES BEARING ON A

SLAB OR FORMWORK

Bar size

B or F dimension, in. (mm)

NO. 3 (NO. 10)

4 (100)

NO. 4 (NO. 13)

6 (150)

NO. 5 (NO. 16)

8 (200)

NO. 6 (NO. 19)

10 (250)

NO. 7 (NO. 22)

12 (300)

NO. 8 (NO. 25)

14 (350)

B and F legs apart or squeezing them together), but have a tendency to twist and collapse under heavy loading. Once Type 26 standees are bent, they cannot be adjusted. As indicated previously, field-bent Type S1 bars are a good choice for ensuring tight tolerances, and they also allow on-site height adjustments. If standees must be taller than about 4 ft (1.2 m), they can be unstable. This can be remedied by securing them in both directions with continuous No. 4 or 5 (No. 13 or 16) tie bars at about midheight. One final note: detailers should always double and triple check their calculations for the height of the standees. The geometry is unusual, so it’s common to see errors in the calculations. References 1. CRSI Committee on Reinforcing Bar Detailing, Reinfo rcing Bar Detailing , 4th edition, Concrete Reinforcing Steel Institute, Schaumburg, IL, 2000, p. C-2. Thanks to Dick Birley, President of Condor Rebar Consultants, Inc., in Vancouver, BC, Canada, for providing the answer to this quest ion. Concrete international

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Index Volume 30 January through December December 2008

A Acceptance Criteria —Evaluation —Evaluation Service Helps Innovative Products Enter Market—Marion Maguire, November 2008 ................................................ ......................................................................... .....................................57 ............57 Accessories Accelerate Handset System—Martin Howes, December 2008 .......................................................... ..................................................................58 ........58 ACI 318 —Fire Resistance Dilemma, A—William L. Gamble, April 2008 ................................................ ......................................................................... .....................................63 ............63 —Reorganizing ACI 318—Randall W. Poston and Charles W. Dolan, July 2008................................................ .................................................................57 .................57 —Strut-and-Tie Models for Deep Beam Design—Gustavo J. Parra-Montesinos, December 2008 .................................41 .................................41 ACI Code Requirements for Repair of Buildings — Lawrence F. Kahn, April 2008...........................................51 ...........................................51 ACI Committee 120 —Landmark Papers in Concrete Materials Research, March March 2008 ............................ ....................................54 ........54 ACI Foundation —Delivering Practical Solutions to the Concrete Industry— Joseph Sanders and Claude Bédard, July 2008 .............27 .............27 —Meeting Needs and Growing Potential—Claude Bédard, Debrethann Orsak, and Joseph Sanders, August 2008 ................................................ ......................................................................... .....................................24 ............24 ACI Publications Committee —Landmark Papers in Concrete Materials Research, Research, March March 2008 ...................54 ...................54 Adhesive Anchor Installation and Inspection — Richard E. Wollmershauser and Lee Mattis, December 2008 ................................................ ......................................................................... .....................................36 ............36

86

MARCH 2009


Admixture —Energizing Concrete—Mark A. Bury and Jeffrey R. Bury, January 2008...........................................42 ...........................................42 Aïtcin, Pierre-Claude—Hidden Meaning of Water-Cement Ratio, The, May 2008................................................. .........................................................51 ........51 Ament, Tom—Designing a Concrete Competition, August 2008 ................................................ ......................................................................... .....................................59 ............59 Architectural Concrete—Pulitzer Foundation for the Arts, The—Joe Nasvik, October 2008 ......................................67 ......................................67 Assessing Vibrations —Jeffrey S. West, Matthew J. Innocenzi, Fernando V. Ulloa, and Randall W. Poston, October 2008..................................... 2008.............................................................. .................................47 ........47 Assessment of Epoxy Coating on Bridge Deck Reinforcement —Richard E. Weyers, Michael C. Brown, Andrei Ramniceanu, and Michael M. Sprinkel, June 2008 ........55 At Home in a Dome —M.K. Hurd, September 2008 ..........48 ..........48 Automatic Detailing of Reinforcement —Greg Birley, November 2008.......................................... ..................................................................41 ........................41 Automation—Productivity Tools for the Concrete Testing Laboratory—Richard Gedney, June 2008.......................52 Avoiding Avoiding the Dead Zone—Dick Birley, April 2008 ...........60

B Baluch, Mohammed H.—Calculating Drying-Shrinkage Stresses, July 2008 ............................................................37 ............................................................37 Bédard, Claude —Delivering Practical Solutions to the Concrete Industry, July 2008 ................................................. ......................................................................... ............................27 ....27 —Meeting Needs and Growing Potential, August 2008 ....24

Benmokrane, Brahim—Pavement System Suiting Local Conditions, November 2008.............................................34 .............................................34 Bentz, Dale P.—Hidden Meaning of Water-Cement Ratio, The, May 2008.............................................. ....................................................................51 ......................51 Benus, Edward—Flattooing Concrete Surfaces, August 2008 ............................................... ....................................................................... ......................................48 ..............48 Bidding—Contractors’ Guide to Mass Concrete—Bruce A. Supren Suprenant ant and Ward R. Malisch, Januar y 2008 ..............37 Birley, Dick —Avoiding the Dead Zone, April 2008 ...............................60 ...............................60 —Reinforcement Placing Drawings are not Shop Drawings, December 2008.............................................. ................................................48 ..48 Birley, Greg —Automatic Detailing of Reinforcement, November 2008........................................ ................................................................ ..........................41 ..41 Bottenberg, Ray—Cathodic Protection of Historic Bridges, September 2008 ....................................................... .................................................................37 ..........37 Bozzo, Luis —Prestressed Partially Precast System, A, February 2008 .............................................. ....................................................................35 ......................35 Brewin, Peter —Concrete —Concrete Cloth, November 2008 ............46 Bridges—Cathodic Protection of Historic Bridges—Ray Bottenberg, September 2008 ...........................................37 ...........................................37 Brown, Michael C. —Assessment of Epoxy Coating on Bridge Deck Reinforcement, June 2008 ..........................55 ..........................55 Building Code—Reorganizing ACI 318—Randall W. Poston and Charles W. Dolan, D olan, July 2008 ......................................57 ......................................57 Bury, Jeffrey R. —Energizing Concrete, January 2008 .... ....42 42 Bury, Mark A.—Energizing Concrete, January 2008........42

C Calculating Drying-Shrinkage Stresses —Mohammed H. Baluch, Muhammad Kalimur Rahman, and Isam A. Mahmoud, July J uly 2008 ........................................... .........................................................37 ..............37 Cao, Xia —Waterproofing —Waterproofing Below-Grade Shotcrete Walls, November 2008........................................ ................................................................ ..........................50 ..50 Cathodic Protection of Historic Bridges—Ray Bottenberg, September 2008 ....................................................... .................................................................37 ..........37 C e r t i f i c a t i o n —Mixing Certification with Higher Education—Luke M. Snell, November 2008 ...................53 ...................53 Certifying Decorative Concrete Contractors —Todd A. Scharich, August 2008 .................................................... ......................................................43 ..43 Code—ACI Code Requirements for Repair of Buildings— Lawrence F. Kahn, April 2008...........................................51 ...........................................51 COIN: Concrete Innovation Center —Tor —Tor Arne Hammer, December 2008 ........................................................ ..................................................................51 ..........51 Compressive Strength —The Hidden Meaning of WaterCement Ratio—Dale P. Bentz and Pierre-Claude Aïtcin, May 2008....................................... 2008............................................................... ......................................51 ..............51 Concrete Cloth —William Crawford and Peter Brewin, November 2008........................................ ................................................................ ..........................46 ..46 Concrete Dumping Height Specification Specification—Cristian Masana, February 2008 .............................................. ....................................................................40 ......................40 Concrete Homes—Disaster-Resistant —Disaster-Resistant Shell Houses—Cloyd E. Warnes, May 2008 ....................................................... .........................................................39 ..39 Concrete Houses Alive and Well After More Than 80 Years—M.K. Hurd, May 2008 ...........................................34 ...........................................34

Congestion—Avoiding the Dead Zone—Dick Birley, April 2008 ............................................... ....................................................................... ......................................60 ..............60 Constraints on Reinforcing Bar Modeling —CRSI Staff, November 2008........................................ ................................................................. ..........................60 .60 Constructibility—Avoiding the Dead Zone—Dick Birley, April 2008 ............................................................. ...........................................................................60 ..............60 Continuously Reinforced Concrete Pavement—Pavement System Suiting Local Conditions—Brahim Benmokrane, Mohamed Eisa, Sherif El-Gamal, Denis Thébeau, and Ehab El-Salakawy, El-Salakawy, November 2008............................................34 ............................................34 Contractors’ Guide to Mass Concrete —Bruce A. Suprenant and Ward Ward R. Malisch, January 2008 ................................37 ................................37 Corrosion—Our Aging Infrastructure—Andy Marquardt, September 2008 ........................... ................................................... ......................................52 ..............52 Crawford, William—Concrete Cloth, November 2008 ....46 —Constraints on Reinforcing Bar Modeling, CRSI Staff —Constraints November 2008........................................ ................................................................. ..........................60 .60 Curing Compound—Specifying Conformance with ASTM C1315—John C1315—John C. Hukey, Hukey, March 2008 ..........................51 Curved-Bar Nodes—Gary J. Klein, September 2008 ........42 Cusum Analysis —Density—Is it Worth Measuring?— Ken W. Day, Day, January 2008 ................................................ .................................................47 .47

D Darling, Jason —Waterproofing Below-Grade Shotcrete Walls, November 2008 ................................................. ......................................................50 .....50 Day, Ken W.—Density—Is it Worth Measuring?, January 2008 ............................................... ....................................................................... ......................................47 ..............47 Decorative Concrete —Certifying Decorative Concrete Contractors—Todd A. Scharich, August 2008 ..................................................... ......................................................43 .43 —Flattooing Concrete Surfaces—Tamryn Doolan and Edward Benus, August 2008.............................................48 .............................................48 Decorative Concrete Success Starts Early —Chris Sullivan, August 2008.............................................. ....................................................................... ..........................40 .40 Delamination—Minimally Invasive Delamination Repairs— Nelson R. Tonet, Tonet, July 2008 .......................................... ...............................................50 .....50 Delivering Practical Solutions to the Concrete Industry — Joseph Sanders and Claude Bédard, July 2008 .............27 Demuynck, Annelies—Phase One of Wind Project Winds Down, October 2008.................................... 2008..........................................................41 ......................41 Density—Is it Worth Measuring? —Ken W. Day, January 2008 ............................................... ....................................................................... ......................................47 ..............47 Designing a Concrete Competition —Allyn Luke and Tom Ament, August 2008 ............................................ ..........................................................59 ..............59 Detailing —Automatic Detailing of Reinforcement—Greg Birley, November 2008........................................ ................................................................. ..........................41 .41 —Curved-Bar Nodes—Gary J. Klein, September 2008 .....42 —Reinforcement Placing Drawings are not Shop Drawings—Dick Birley, December 2008 .........................48 .........................48 Deterioration —Assessment of Epoxy Coating on Bridge Deck Reinforcement—Richard E. Weyers, Michael C. Brown, Andrei Ramniceanu, and Michael M. Sprinkel, June 2008 ............................................... ....................................................................... ......................................55 ..............55 Concrete international

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Diaphragm—Practical Finite Element Analysis—Myoungsu Shin, Benjamin Pimentel, and Jacob Grossman, October 2008 ................................................ ......................................................................... .....................................71 ............71 Disaster-Resistant Shell Houses—Cloyd E. Warnes, May 2008 ................................................ ......................................................................... .....................................39 ............39 Dolan, Charles W.—Reorganizing ACI 318, July 2008 ......57 Doolan, Tamryn —Flattooing Concrete Surfaces, August 2008 ................................................ ......................................................................... .....................................48 ............48 Drill —Maintaining Productivity—Raymond Reub, December 2008 ...................................................... ..................................................................55 ............55

E Education—Mixing Certification with Higher Education— Luke M. M . Snell, November 2008 .........................................53 .........................................53 Eisa, Mohamed —Pavement System Suiting Local Conditions, November 2008.............................................34 .............................................34 El-Gamal, Sherif —Pavement — Pavement System Suiting Local Conditions, November 2008.............................................34 .............................................34 El-Salakawy, Ehab —Pavement System Suiting Local Conditions, November 2008.............................................34 .............................................34 Energizing Concrete—Mark A. Bury and Jeffrey R. Bury, January 2008 ............................................. ......................................................................42 .........................42 Engineered Wood Used in Formwork—M.K. Hurd, June 2008 ................................................ ......................................................................... .....................................45 ............45 Epoxy Coating—Assessment of Epoxy Coating on Bridge Deck Reinforcement—Richard E. Weyers, Michael C. Brown, Andrei Ramniceanu, and Michael M. Sprinkel, June 2008 ................................................ ......................................................................... .....................................55 ............55 Evaluation Service Helps Innovative Products Enter Market—Marion Maguire, November 2008....................57 Extending the Service Life of Parking Structures —K. Nam Shiu and Kyle Stanish, April 2008 ....................................43 ....................................43 External Prestressing —Strengthening by External Prestressing—C. Prestressing—C. Antony Jeyasehar and G. Mohankumar, Mohankumar, October 2008..................................... 2008............................................................. .................................61 .........61

F Fiber —Concrete —Concrete Cloth—William Crawford and Peter Brewin, November 2008......................................... ..................................................................46 .........................46 Fiber-Reinforced Concrete —New Frontiers Fronti ers for Steel Fiber-Rein Fi ber-Reinforced forced Concrete—Ja Concrete —Ja¯nis ¯nis Ošlejs, May 2008 ............................................... ................................................................45 .................45 —Ultra High-Performance Concretes—Pierre Rossi, February 2008 ........................................... ....................................................................31 .........................31 Fiber-Reinforced Polymer —Pavement —Pavement System Suiting Local Conditions—Brahim Benmokrane, Mohamed Eisa, Sherif El-Gamal, Denis Thébeau, and Ehab El-Salakawy, November 2008......................................... ..................................................................34 .........................34 Finishing—Certifying Decorative Concrete Contractors— Todd A. Scharich, August 2008........................................43 ........................................43 Finite Element Analysis —Calculating Drying-Shrinkage Stresses—Mohammed H. Baluch, Muhammad Kalimur Rahman, and Isam A. Mahmoud, July 2008 ........................................ .........................................................37 .................37

88

MARCH 2009


—Practical Finite Element Analysis—Myoungsu Shin, Benjamin Pimentel, and Jacob Grossman, October 2008 ................................................ ......................................................................... .....................................71 ............71 Fire Endurance—Fire Resistance Dilemma, A—William L. Gamble, April 2008 ................................ ........................................................ ............................63 ....63 Fire Resistance Dilemma, A—William L. Gamble, April 2008 ................................................ ......................................................................... .....................................63 ............63 Flat Plate—Over the Neighbors—Ahmed Osman, February 2008 ................................................ ......................................................................... .....................................43 ............43 —Tamryn Doolan D oolan and Edward Flattooing Concrete Surfaces—Tamryn Benus, August 2008 ............................... ....................................................... ............................48 ....48 Flexibility and Strength by Design —Rolf Spahr, June 2008 ................................................ ......................................................................... .....................................50 ............50 Flying Form—Formwork Efficiencies—Cary Kopczynski, June 2008 ................................................ ........................................................................ ............................41 ....41 Formwork —Accessories Accelerate Handset System—Martin Howes, December 2008 .......................................................... ..................................................................58 ........58 —Engineered Wood Used in Formwork—M.K. Hurd, June 2008 ................................................ ......................................................................... .....................................45 ............45 —Flexibility and Strength by Design—Rolf Spahr, June 2008 ................................................ ......................................................................... .....................................50 ............50 —Pulitzer Foundation for the Arts, The—Joe Nasvik, October 2008 ................................................ ......................................................................... .....................................67 ............67 Formwork Efficiencies —Cary Kopczynski, June 2008 ................................................ ......................................................................... .....................................41 ............41 Formwork Removal Specification—Cristian Masana, June 2008 ................................................ ......................................................................... .....................................38 ............38 Foundation —Phase One of Wind Project Winds Down—Annelies Demuynck and Nathalie Gunst, October 2008 ...............41 —Waterproofing Below-Grade Shotcrete Walls—Jason Darling and Xia Cao, November 2008 .............................50 .............................50 Free Fall—Concrete Dumping Height Specification—Cristian Masana, Masana, February 2008 ............................................. .....................................................40 ........40 Freezing and Thawing Cycle—Pervious Concrete in Severe Exposures—John T. Kevern, Kejin Wang, and Vernon R. Schaefer, Schaefer, July 2008 ........................................................ ............................................................43 ....43 Fudala, David—Understanding and Specifying F-min, July 2008 ................................................ ......................................................................... .....................................52 ............52

G Gamble, William L.—Fire Resistance Dilemma, A, April 2008 ................................................ ......................................................................... .....................................63 ............63 Gedney, Richard—Productivity Tools for the Concrete Testing Testing Laboratory, June 2008.........................................52 .........................................52 Grossman, Jacob —Practical Finite Element Analysis, October 2008..................................... 2008.............................................................. .................................71 ........71 Gunst, Nathalie—Phase One of Wind Project Winds Down, October 2008..................................... 2008.............................................................. .................................41 ........41

H Hammer, Tor Arne—COIN: Concrete Innovation Center, December 2008 .......................................................... ..................................................................51 ........51

Hardened Shelter —Concrete Cloth—William Crawford and Peter Brewin, November 2008 .........................................46 Heat Island—Solar Reflectance Values for Concrete— Medgar L. Marceau and Martha G. VanGeem, August 2008 .....................................................................................52 High-Performance Concrete—Ultra High Performance Concretes—Pierre Rossi, February 2008 .......................31 History —Concrete Houses Alive and Well After More Than 80 Years—M.K. Hurd, May 2008 ...........................................34 —Landmark Papers in Concrete Materials Research—ACI Publications Committee and ACI Committee 120, March 2008 .....................................................................................54 Howes, Martin—Accessories Accelerate Handset System, December 2008 ..................................................................58 Hukey, John C. —Specifying Conformance with ASTM C1315, March 2008 .....................................................51 Hurd, M.K. —At Home in a Dome, September 2008 .............................48 —Concrete Houses Alive and Well After More Than 80 Years, May 2008.............................................................................34 —Engineered Wood Used in Formwork, June 2008 ..........45

I Innocenzi, Matthew J. —Assessing Vibrations, October 2008 .....................................................................................47 Inspection —Post-Earthquake Assessment of Bridge Columns—Marc J. Veletzos, Marios Panagiotou, Yael Van Den Einde, José I. Restrepo, and Stephen Sahs, March 2008 .....................................................................................61

J Jeyasehar, C. Antony —Strengthening by External Prestressing, October 2008 ..............................................61

K Kahn, Lawrence F.—ACI Code Requirements for Repair of Buildings, April 2008 .........................................................51 Kevern, John T.—Pervious Concrete in Severe Exposures, July 2008 .............................................................................43 Kim, Haejin—On Aggregate Grading, March 2008 .....45 Klein, Gary J.—Curved-Bar Nodes, September 2008......42 Kopczynski, Cary—Formwork Efficiencies, June 2008 ...41

L Landmark Papers in Concrete Materials Research —ACI Publications Committee and ACI Committee 120, March 2008 .....................................................................................54 Long-Span Structure—Vertical Integration at Vanderbilt University—Otto J. Schwarz, October 2008...................54 Luke, Allyn—Designing a Concrete Competition, August 2008 .....................................................................................59

M Maguire, Marion—Evaluation Service Helps Innovative Products Enter Market, November 2008 ........................57 Mahmoud, Isam A. —Calculating Drying-Shrinkage Stresses, July 2008 ............................................................37 Maintaining Productivity —Raymond Reub, December 2008 .....................................................................................55 Maintenance —Maintaining Productivity—Raymond Reub, December 2008 ..................................................................55 Malisch, Ward R.—Contractors’ Guide to Mass Concrete, January 2008 ......................................................................37 Marceau, Medgar L.—Solar Reflectance Values for Concrete, August 2008........................................................................52 Marquardt, Andy—Our Aging Infrastructure, September 2008 .....................................................................................52 Masana, Cristian —Concrete Dumping Height Specification, February 2008 .....................................................................................40 —Formwork Removal Specification, June 2008 ................38 Mass Concrete—Contractors’ Guide to Mass Concrete—Bruce A. Suprenant and Ward R. Malisch, January 2008 ..........37 Materials —Landmark Papers in Concrete Materials Research—ACI Publications Committee and ACI Committee 120, March 2008............................................54 Mattis, Lee—Adhesive Anchor Installation and Inspection, December 2008 ..................................................................36 Maturity Method —Formwork Removal Specification— Cristian Masana, June 2008..............................................38 Meeting Needs and Growing Potential—Claude Bédard, Debrethann Orsak, and Joseph Sanders, August 2008 .....................................................................................24 Minimally Invasive Delamination Repairs —Nelson R. Tonet, July 2008 .................................................................50 Mixing Certification with Higher Education—Luke M. Snell, November 2008..................................................................53 Mixture Proportioning —On Aggregate Grading—Karthik H. Obla and Haejin Kim, March 2008 ........................................................45 —Packing More Value into the Mix—William D. Palmer Jr., January 2008 ......................................................................51 Modeling—Constraints on Reinforcing Bar Modeling—CRSI Staff, November 2008 ........................................................60 Mohankumar, G.—Strengthening by External Prestressing, October 2008......................................................................61

N Nasvik, Joe—Pulitzer Foundation for the Arts, The, October 2008 .....................................................................................67 New Frontiers for Steel Fiber-Reinforced Concrete —Janis Ošlejs, May 2008 ................................................................45 Norway—COIN: Concrete Innovation Center—Tor Arne Hammer, December 2008 .................................................51 Concrete international

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O Obla, Karthik H. —On Aggregate Grading, March 2008............................................................................45 On Aggregate Grading —Karthik H. Obla and Haejin Kim, March 2008 ................................................................45 Orsak, Debrethann—Meeting Needs and Growing Potential, August 2008........................................................................24 Ošlejs, Ja¯nis —New Frontiers for Steel Fiber-Reinforced Concrete, May 2008...........................................................45 Osman, Ahmed—Over the Neighbors, February 2008....43 Our Aging Infrastructure—Andy Marquardt, September 2008 .....................................................................................52 Over the Neighbors—Ahmed Osman, Februar y 2008 .....43

P Packing Density—On Aggregate Grading—Karthik H. Obla and Haejin Kim, March 2008 ............................45 Packing More Value into the Mix —William D. Palmer Jr., January 2008 ......................................................................51 Palmer Jr., William D.—Packing More Value into the Mix, January 2008 ......................................................................51 Panagiotou, Marios —Post-Earthquake Assessment of Bridge Columns, March 2008 ...........................................61 Parking Garage—Extending the Service Life of Parking Structures—K. Nam Shiu and Kyle Stanish, April 2008 .....................................................................................43 Parra-Montesinos, Gustavo J. —Strut-and-Tie Models for Deep Beam Design, December 2008................................41 Pavement System Suiting Local Conditions —Brahim Benmokrane, Mohamed Eisa, Sherif El-Gamal, Denis Thébeau, and Ehab El-Salakawy, November 2008 .........34 Performance Specification —Concrete Dumping Height Specification—Cristian Masana, February 2008 ....................................................................40 —Formwork Removal Specification—Cristian Masana, June 2008 .....................................................................................38 Pervious Concrete in Severe Exposures—John T. Kevern, Kejin Wang, and Vernon R. Schaefer, July 2008 .............43 Phase One of Wind Project Winds Down —Annelies Demuynck and Nathalie Gunst, October 2008 ...............41 Pimentel, Benjamin—Practical Finite Element Analysis, October 2008......................................................................71 Poppoff, Mike—Standing on a Success Story, January 2008 .....................................................................................34 Post-Earthquake Assessment of Bridge Columns —Marc J. Veletzos, Marios Panagiotou, Yael Van Den Einde, José I. Restrepo, and Stephen Sahs, March 2008 ......................61 Post-Installed Anchor —Adhesive Anchor Installation and Inspection—Richard E. Wollmershauser and Lee Mattis, December 2008 ..................................................................36 Post-Tensioned Concrete —Assessing Vibrations—Jeffrey S. West, Matthew J. Innocenzi, Fernando V. Ulloa, and Randall W. Poston, October 2008......................................................................47

90

MARCH 2009


—Over the Neighbors—Ahmed Osman, Februar y 2008 ....43 —Phase One of Wind Project Winds Down—Annelies Demuynck and Nathalie Gunst, October 2008 ...............41 —Vertical Integration at Vanderbilt University—Otto J. Schwarz, October 2008 .....................................................54 Poston, Randall W. —Assessing Vibrations, October 2008 ...............................47 —Reorganizing ACI 318, July 2008 ......................................57 Practical Finite Element Analysis —Myoungsu Shin, Benjamin Pimentel, and Jacob Grossman, October 2008 .....................................................................................71 Precast Concrete—Prestressed Partially Precast System, A—Luis Bozzo, February 2008.........................................35 Preconstruction Planning—Decorative Concrete Success Starts Early—Chris Sullivan, August 2008 .....................40 Preliminary Design —Formwork Efficiencies—Cary Kopczynski, June 2008......................................................41 Prestressed Partially Precast System, A —Luis Bozzo, February 2008 ....................................................................35 Product Evaluation—Evaluation Service Helps Innovative Products Enter Market—Marion Maguire, November 2008 .....................................................................................57 Productivity Tools for the Concrete Testing Laboratory — Richard Gedney, June 2008 ..............................................52

Q Quality Control —Decorative Concrete Success Starts Early—Chris Sullivan, August 2008........................................................................40 —Density—Is it Worth Measuring?—Ken W. Day, January 2008 .....................................................................................47 —Packing More Value into the Mix—William D. Palmer Jr., January 2008 ......................................................................51

R Rahman, Muhammad Kalimur — Calculating DryingShrinkage Stresses, July 2008 ..........................................37 Ramniceanu, Andrei—Assessment of Epoxy Coating on Bridge Deck Reinforcement, June 2008 ..........................55 Reinforcement Placing Drawings are not Shop Drawings—Dick Birley, December 2008.........................48 Reinforcing Bar — Our Aging Infrastructure—Andy Marquardt, September 2008 ............................................52 Reorganizing ACI 318—Randall W. Poston and Charles W. Dolan, July 2008.................................................................57 Repair —ACI Code Requirements for Repair of Buildings— Lawrence F. Kahn, April 2008...........................................51 —Cathodic Protection of Historic Bridges—Ray Bottenberg, September 2008 .................................................................37 —Extending the Service Life of Parking Structures—K. Nam Shiu and Kyle Stanish, April 2008 ....................................43 —Minimally Invasive Delamination Repairs—Nelson R. Tonet, July 2008 .................................................................50

—Strengthening by External Prestressing—C. Antony Jeyasehar and G. Mohankumar, October 2008 ..............61 Research —COIN: Concrete Innovation Center—Tor Arne Hammer, December 2008 ..................................................................51 —Delivering Practical Solutions to the Concrete Industry— Joseph Sanders and Claude Bédard, July 2008 ............27 Residential —Concrete Houses Alive and Well After More Than 80 Years—M.K. Hurd, May 2008 ...........................................34 —Disaster-Resistant Shell Houses—Cloyd E. Warnes, May 2008 .....................................................................................39 Residential Concrete—At Home in a Dome—M.K. Hurd, September 2008 .................................................................48 Restrepo, José I.—Post-Earthquake Assessment of Bridge Columns, March 2008 .......................................................61 Reub, Raymond—Maintaining Productivity, December 2008 .....................................................................................55 Rheology —Energizing Concrete—Mark A. Bury and Jeffrey R. Bury, January 2008 ...........................................42 Rossi, Pierre —Ultra High-Performance Concretes, February 2008 ....................................................................31

S Sahs, Stephen—Post-Earthquake Assessment of Bridge Columns, March 2008 .......................................................61 Sanders, Joseph —Delivering Practical Solutions to the Concrete Industry, July 2008 .............................................................................27 —Meeting Needs and Growing Potential, August 2008 ....24 Schaefer, Vernon R. —Pervious Concrete in Severe Exposures, July 2008.........................................................43 Scharich, Todd A. —Certifying Decorative Concrete Contractors, August 2008.................................................43 Schedule—Reinforcement Placing Drawings are not Shop Drawings—Dick Birley, December 2008 .........................48 Schwarz, Otto J. —Vertical Integration at Vanderbilt University, October 2008 ..................................................54 Shear —Strut-and-Tie Models for Deep Beam Design— Gustavo J. Parra-Montesinos, December 2008 ..............41 Shin, Myoungsu —Practical Finite Element Analysis, October 2008......................................................................71 Shiu, K. Nam —Extending the Service Life of Parking Structures, April 2008 .......................................................43 Shop Drawing—Reinforcement Placing Drawings are not Shop Drawings—Dick Birley, December 2008 ...............48 Shoring —Accessories Accelerate Handset System—Martin Howes, December 2008 ....................................................58 Shotcrete —At Home in a Dome—M.K. Hurd, September 2008........48 —Waterproofing Below-Grade Shotcrete Walls—Jason Darling and Xia Cao, November 2008 .............................50 Shrinkage —Calculating Drying-Shrinkage Stresses—Mohammed H. Baluch, Muhammad Kalimur Rahman, and Isam A. Mahmoud, July 2008 .........................................................37

—Standing on a Success Story—Mike Poppoff, January 2008 .....................................................................................34 Slab-On-Ground —Specifying Conformance with ASTM C1315—John C. Hukey, March 2008 ....................................................51 —Standing on a Success Story—Mike Poppoff, January 2008 .....................................................................................34 —Understanding and Specifying F-min—David Fudala, July 2008 .....................................................................................52 Slab-On-Piles—New Frontiers for Steel Fiber-Reinforced Concrete—Ja¯nis Ošlejs, May 2008 .................................. 45 Snell, Luke M.—Mixing Certification with Higher Education, November 2008..................................................................53 Software —Automatic Detailing of Reinforcement—Greg Birley, November 2008..................................................................41 —Constraints on Reinforcing Bar Modeling—CRSI Staff, November 2008..................................................................60 Solar Reflectance Values for Concrete —Medgar L. Marceau and Martha G. VanGeem, August 2008............................52 Spahr, Rolf —Flexibility and Strength by Design, June 2008 .....................................................................................50 Special Inspection—Adhesive Anchor Installation and Inspection—Richard E. Wollmershauser and Lee Mattis, December 2008 ..................................................................36 Specifying Conformance with ASTM C1315 —John C. Hukey, March 2008 ....................................................51 Sprinkel, Michael M.—Assessment of Epoxy Coating on Bridge Deck Reinforcement, June 2008 ..........................55 Standing on a Success Story —Mike Poppoff, January 2008 .....................................................................................34 Stanish, Kyle —Extending the Service Life of Parking Structures, April 2008 .......................................................43 Stencil—Flattooing Concrete Surfaces—Tamryn Doolan and Edward Benus, August 2008.............................................48 Strategic Development Council —Meeting Needs and Growing Potential—Claude Bédard, Debrethann Orsak, and Joseph Sanders, August 2008 ...................................24 Strengthening by External Prestressing —C. Antony Jeyasehar and G. Mohankumar, October 2008 ..............61 Strut-and-Tie Model—Curved-Bar Nodes—Gary J. Klein, September 2008 .................................................................42 Strut-and-Tie Models for Deep Beam Design —Gustavo J. Parra-Montesinos, December 2008 .................................41 Student Competition —Designing a Concrete Competition—Allyn Luke and Tom Ament, August 2008 .....................................................................................59 Sullivan, Chris—Decorative Concrete Success Starts Early, August 2008........................................................................40 Superflat Floor —Understanding and Specifying F-min— David Fudala, July 2008 ....................................................52 Suprenant, Bruce A.—Contractors’ Guide to Mass Concrete, January 2008 ......................................................................37 Sustainability —Engineered Wood Used in Formwork—M.K. Hurd, June 2008 .....................................................................................45 Concrete international

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—Pervious Concrete in Severe Exposures—John T. Kevern, Kejin Wang, and Vernon R. Schaefer, July 2008 .............43 —Solar Reflectance Values for Concrete—Medgar L. Marceau and Martha G. VanGeem, August 2008 ...........52

T Testing —Designing a Concrete Competition—Allyn Luke and Tom Ament, August 2008 ..........................................................59 —Productivity Tools for the Concrete Testing Laboratory—Richard Gedney, June 2008.......................52 Thébeau, Denis —Pavement System Suiting Local Conditions, November 2008.............................................34 The Hidden Meaning of Water-Cement Ratio —Dale P. Bentz and Pierre-Claude Aïtcin, May 2008 ................................51 The Pulitzer Foundation for the Arts —Joe Nasvik, October 2008 .....................................................................................67 Tonet, Nelson R.—Minimally Invasive Delamination Repairs, July 2008 .............................................................................50 Transportation—Post-Earthquake Assessment of Bridge Columns—Marc J. Veletzos, Marios Panagiotou, Yael Van Den Einde, José I. Restrepo, and Stephen Sahs, March 2008 .....................................................................................61 Two-Way Slab —Prestressed Partially Precast System, A—Luis Bozzo, February 2008.........................................35

U Ulloa, Fernando V. —Assessing Vibrations, October 2008 .....................................................................................47 Ultra High-Performance Concretes —Pierre Rossi, February 2008 ....................................................................31 Understanding and Specifying F-min—David Fudala, July 2008 .....................................................................................52

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MARCH 2009


V Van Den Einde, Yael —Post-Earthquake Assessment of Bridge Columns, March 2008 ...........................................61 VanGeem, Martha G. —Solar Reflectance Values for Concrete, August 2008 ......................................................52 Veletzos, Marc J.—Post-Earthquake Assessment of Bridge Columns, March 2008 .......................................................61 Vertical Integration at Vanderbilt University —Otto J. Schwarz, October 2008 .....................................................54 Vibration —Assessing Vibrations—Jeffrey S. West, Matthew J. Innocenzi, Fernando V. Ulloa, and Randall W. Poston, October 2008......................................................................47

W Wall—Flexibility and Strength by Design—Rolf Spahr, June 2008 .....................................................................................50 Wang, Kejin—Pervious Concrete in Severe Exposures, July 2008 .....................................................................................43 Warnes, Cloyd E.—Disaster-Resistant Shell Houses, May 2008 .....................................................................................39 Water-Cement Ratio —Hidden Meaning of Water-Cement Ratio, The—Dale P. Bentz and Pierre-Claude Aïtcin, May 2008 .....................................................................................51 Waterproofing Below-Grade Shotcrete Walls —Jason Darling and Xia Cao, November 2008 .............................50 West, Jeffrey S. —Assessing Vibrations, October 2008 ...47 Weyers, Richard E. —Assessment of Epoxy Coating on Bridge Deck Reinforcement, June 2008 ..........................55 Wollmershauser, Richard E.—Adhesive Anchor Installation and Inspection, December 2008 ......................................36

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Concrete International Magazine March 2009

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