Eleventh U.S. National Conference on Earthquake Engineering Integrating Science, Engineering & Policy June 25-29, 2018 Los Angeles, California
SHAPE MEMORY ALLOY FOR BRIDGE COLUMNS M. Tazarv1 and M.S. Alam 2 ABSTRACT
Reinforced concrete (RC) bridge columns are currently designed to withstand severe earthquakes without collapse, but damage of concrete and yielding of reinforcing steel bars are allowed. Excessive damage and large residual displacements may significantly affect the bridge serviceability since the bridge has to be decommissioned for repair or even total replacement. Nevertheless, bridge damage or permanent deformations can be minimized using advanced materials and novel technologies. Of which, shape memory alloy (SMA) has gained a substantial momentum in the USA. SMA has been used in many forms such as longitudinal and transverse reinforcement, and fibers in concrete. A state-of-the-art review of the application of SMA in bridge columns was conducted. Material and large-scale SMA-reinforced component tests were performed, extensive parametric study was carried out, a survey of state departments of transportation was conducted, and design and construction guidelines were proposed. proposed. The extended abstract and the presentation highlight the findings of the experimental and analytical studies.
1
Assistant Professor, Dept. of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007 (email:
[email protected])
[email protected]) 2 Associate Professor, School of Engineering, University of British Columbia, Kelowna, BC Canada V1V 1V7 (email:
[email protected])
[email protected]) Tazarv M, Alam MS. Shape Memory Alloy for Bridge Columns. Proceedings Columns. Proceedings of the 11th National Conference in Earthquake Engineering , Earthquake Engineering Research Institute, Los Angeles, CA. 2018.
Eleventh U.S. National Conference on Earthquake Engineering Integrating Science, Engineering & Policy June 25-29, 2018 Los Angeles, California
Shape Memory Alloy for Bridge Columns M. Tazarv1 and M.S. Alam2
ABSTRACT Reinforced concrete (RC) bridge columns are currently designed to withstand severe earthquakes without collapse, but damage of concrete and yielding of reinforcing steel bars are allowed. Excessive damage and large residual displacements may significantly affect the bridge serviceability since the bridge has to be decommissioned for repair or even total replacement. Nevertheless, bridge damage or permanent deformations can be minimized using advanced materials and novel technologies. Of which, shape memory alloy (SMA) has gained a substantial momentum in the USA. USA. SMA has been used in many forms forms such as longitudinal and transverse reinforcement, and fibers fibers in concrete. A state-of-the-art review of the application application of SMA in bridge columns was conducted. Material and large-scale SMA-reinforced component tests were performed, extensive parametric study was carried out, a survey of state departments of transportation was conducted, and design and construction construction guidelines were proposed. The extended abstract and the presentation highlight the findings of the experimental and analytical studies.
Introduction
Reinforced concrete (RC) bridge columns are currently designed to withstand severe earthquakes without collapse, but damage of concrete and yielding of reinforcing steel bars are allowed. Excessive damage and large residual displacements, which are mainly caused by the yielding of steel reinforcement, may significantly affect the bridge serviceability resulting in bridge decommissioning for repair or even total replacement. Nevertheless, RC bridge damage and permanent deformations can be minimized using advanced materials and novel technologies. Figure 1 shows the use of shape memory alloy (SMA), engineered cementitious composite (ECC), ultra-high performance concrete (UHPC), fiber reinforced polymer (FRP), and rubber in the construction of new bridges in the United States by 2017. It can be seen that these advanced materials have been used only in handful projects but they are gaining more interest because of 1
Assistant Professor, Dept. of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007 (email:
[email protected])
[email protected]) 2 Associate Professor, School of Engineering, University of British Columbia, Kelowna, BC Canada V1V 1V7 (email:
[email protected])
[email protected]) Tazarv M, Alam MS. Shape Memory Alloy for Bridge Columns. Proceedings Columns. Proceedings of the 11th National Conference in Earthquake Engineering , Earthquake Engineering Research Institute, Los Angeles, CA. 2018.
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k 3=a.k 1
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Figure 1.
Deployment of advanced materials in new bridge construction by 2017 [20]
Figure 2.
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Superelastic SMA material model [11]
their superior structural performance and durability compared to conventional concrete and steel. Of different advanced materials, SMA is the focus focus of the present study. SMA has been incorporated in large- and full-scale structural component testing in the form of longitudinal bars [e.g. 1-2], confining reinforcement [3], fibers in concrete [e.g. 4], and post-tensioning elements [e.g. 5-6]. SMA refers to a class of metallic materials that can recover its original shape upon heating (shape memory effect) or unloading (superelastic effect). effect). More than 10 alloys of SMA have been developed and new types are emerging [7]. Among those, an alloy alloy of nickel and titanium (commonly referred as NiTi or Nitinol) has gained more interest since NiTi SMA shows very high superelastic strain capacity, low- and high-cycle fatigue resistance, excellent corrosion resistance, and good energy dissipation [8]. A summary of material properties, findings of experimental and analytical studies, and design guidelines for NiTi SMA-reinforced bridge columns are presented herein. Material Models
Several stress-strain models have been developed for NiTi SMA at different austenite and martensite phases [e.g. 9-10]. Tazarv and Saiidi [11] proposed a systematic definition of SMA mechanical properties from structural engineering viewpoint and developed a stress-strain material model for superelastic SMA reinforcement (Fig. 2). Experimental Studies
Large-scale SMA-reinforced bridge column cyclic and shake-table testing showed that these types of columns are low-damage (especially when ECC is incorporated in plastic hinge regions, Fig. 3), ductile (compared to or higher than conventional columns), and have minimal residual displacements (less than 1% of the peak displacement, Fig. 4) [1, 12-15]. For these columns, the damage after a severe earthquake is limited to concrete cover, which can be easily repaired. Analytical Studies
Billah and Alam [16] analytically determined the behavior of a SMA-FRP hybrid-reinforced concrete column under seismic loading. Results indicate that SMA in the plastic plastic hinge region of hybrid column can substantially reduce the residual displacement with adequate energy dissipation capacity during earthquakes. Billah and Alam [17] also developed plastic hinge
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Figure 3.
SMA-reinforced ECC column damage at 10% drift ratio [1]
Figure 4.
Force-drift relationship for SMAreinforced ECC and CIP columns [1]
length expression for SMA-RC bridge columns based on extensive numerical simulations. simulations. Their proposed equation can be used for the design of such columns and to calculate the displacement capacity. Using Incremental Incremental Dynamic Dynamic Analysis (IDA), Billah and Alam [18] [18] developed quantitative damage states corresponding to different performance levels (cracking, yielding, and strength degradation) and specific probabilistic distributions for RC bridge piers reinforced with different types of SMAs. SMA-reinforced concrete columns compared to steel-RC bridge bridge columns show significantly less seismic vulnerability when residual displacement is considered as the engineering demand parameter (EDP) [19]. Design and Construction Guidelines
Saiidi et al. [20] developed a comprehensive design and construction guidelines including a step by-step example for SMA-reinforced bridge columns for deployment in high-seismic regions. The guideline also includes an evaluation procedure to assess different novel bridge columns based on 14 parameters such as structural performance and costs. The world first SMAreinforced ECC bridge was designed based on a similar guideline and was built in Seattle, WA in 2017. Billah and Alam [19, 21] also proposed proposed residual displacement-based seismic design for SMA-reinforced concrete bridge columns where step-by-step design procedure along with design examples were provided. Conclusions
Extensive experimental and analytical studies on SMA-reinforced concrete columns in the past 10 years provided sufficient information to develop design and construction guidelines and to facilitate the deployment of these these types of columns in high-seismic regions. The extended abstract and the presentation highlight the key findings of several studies and are intended to familiarize the audience with general design and construction steps. References 1.
Tazarv M, Saiidi MS. Low-Damage Precast Columns for Accelerated Bridge Construction in High Seismic Zones. Journal Zones. Journal of Bridge Bridge Engineering 2015; 2015; 21 (3): 13 pp.
2.
Youssef MA, Alam MS, Nehdi M. Experimental Investigation on the Seismic Behavior of Beam-Column Joints Reinforced with Superelastic Shape Memory Alloys. Journal Alloys. Journal of Earthquake Earthquake Engineering Engineering 2008; 2008; 12 (7): 12051222.
3.
Andrawes B, Shin M, Wierschem N. Active Confinement of Reinforced Concrete Bridge Columns Using Shape Memory Alloys. Journal Alloys. Journal of Bridge Bridge Engineering 2010; 2010; 15 (1): 81-89.
4.
Shajil S, Srinivasan M, Santhanam M. Self-Centering of Shape Memory Alloy Fiber Reinforced Cement Mortar Members Subjected to Strong Cyclic Loading. Materials Loading. Materials and Structures Structures 2012; 2012; 46 (4): 651-661.
5.
Moser M, Bergamini A, Christen R, Czaderski C. Feasibility of Concrete Prestressed by Shape Memory Alloy Short Fibers. Materials Fibers. Materials and Structures Structures 2005; 2005; 38 (5): 593-600.
6.
Rojob H, El-Hacha R. Self-Prestressing Using Iron-Based Shape Memory Alloy for Flexural Strengthening of Reinforced Concrete Beams. ACI Beams. ACI Structural Journal 2017, 2017, 114 (2): 523-532.
7.
Alam MS, Youssef MA, Nehdi M. Utilizing Shape Memory Alloys to Enhance the Performance and Safety of Civil Infrastructures: a Review. Canadian Journal of Civil Engineering 2007; 2007; 34 (9): 1075-1086.
8.
DesRoches R, Delemont M. Seismic Retrofit of Simply Supported Bridges Using Shape Memory Alloys. Engineering Structures Structures 2002; 2002; 24 (3): 325-332.
9.
Atanackovic T, Achenbach M. Moment-Curvature Relations for a Pseudoelastic Beam. Continuum Mechanics and Thermodynamics 1989; Thermodynamics 1989; 1 (1): 73-80.
10. Graesser EJ, Cozzarelli FA. Shape ‐Memory Alloys as New Materials for Aseismic Isolation. Journal Isolation. Journal of Engineering Mechanics Mechanics 1991; 1991; 117 (11): 2590-608. 11. Tazarv M, Saiidi MS. Reinforcing NiTi Superelastic SMA for Concrete Structures. Journal Structures. Journal of Structural Structural Engineering 2014; 2014; 141 (8): 10 pp. 12. Saiidi MS, Wang H. Exploratory Study of Seismic Response of Concrete Columns with Shape Memory Alloys Reinforcement. ACI Reinforcement. ACI Structural 2006; 103 (3): 436-443. Structural Journal 2006; 13. Cruz-Noguez CA, Saiidi MS. Shake Table Studies of a 4 ‐Span Bridge Model with Advanced Materials. Journal Materials. Journal of Structural Engineering 2012. 2012. 138 (2): 183-192. 14. Nakashoji B, Saiidi MS. Seismic Performance of Square Nickel-Titanium Reinforced ECC Columns with Headed Couplers. Couplers. Center for Civil Engineering Earthquake Research, Department of Civil and Environmental Engineering, University of Nevada, Reno: Nevada, Report Nevada, Report No. CCEER-14-05 CCEER-14-05,, 252 pp, 2014. 15. Varela S, Saiidi, MS. Experimental Study on Seismically Seismically Resilient Two-Span Bridge Models Designed for Disassembly. Journal Disassembly. Journal of Earthquake Earthquake Engineering 2017; 2017; 40 pp. 16. Billah AHMM, Alam MS. Seismic Performance of Concrete Columns Reinforced with Hybrid Shape Memory Alloy (SMA) and Fiber Reinforced Polymer (FRP) Bars. Construction and Building Materials 2016. Materials 2016. 28 (1): 730-742. 17. Billah AHMM, Alam MS. Plastic Hinge Length of Shape Memory Alloy (SMA) Reinforced Concrete Bridge Pier. Engineering Pier. Engineering Structures Structures 2016. 2016. 117 (Jun): 321-331. 18. Billah AHMM, Alam MS. Performance-based Seismic Design of Shape Memory Alloy-Reinforced Alloy-Reinforced Concrete Bridge Piers. I: Development of Performance-based Damage States. Journal States. Journal of Structural Structural Engineering 2016. 2016. 142 (12): 04016140. 19. Billah AHMM, Alam MS. Seismic Fragility Assessment of Concrete Bridge Pier Reinforced with Superelastic Shape Memory Alloy. Earthquake Alloy. Earthquake Spectra 2015. Spectra 2015. 31 (3): 1515-1541. 20. Saiidi MS, Tazarv M, Varela S, Bennion S, Marsh ML, Ghorbani I, Murphy TP. Seismic Design of Bridge Columns with Improved Energy Dissipating Mechanisms. National Cooperative Highway Research Program: Washington DC: 2017.
21. Billah AHMM, Alam MS. Performance-Based Seismic Design of Shape Memory Alloy-Reinforced Alloy-Reinforced Concrete Bridge Piers. II: Methodology and Design Example. Journal Example. Journal of Structural Structural Engineering 2016. 2016. 142 (12): 04016141.
