STUDIES ON EXPANDED POLYSTYRENE CONCRETE A Report submitted in partial fulfillment for the Degree of B. Tech in Civil Engineering by SHRUTI N.C (1121A!1"# (1121A!1"# $AHA%ALA &A'RUTHI REDDY (1121A!1)# ANNADI YASHASREE (1121A!1*# ILLURI DI+YA (1121A!12# $ITTAPALLY RA$YA (1121A!12# CH. $OUNI%A $OU NI%A (1121A!111# (1121A!111#
Un,er -he gi,/nce 0 $r. +. +. SRINI+A SRIN I+ASA SA REDDY RED DY (A0ci/-e Pr0e0r# De3/r-4en- 0 Civil Engineering
'O%ARA&U RAN'ARA&U INSTITUTE O5 EN'INEERIN' AND TECHNOLO'Y HYDERABAD
(Affiliated to Jawaharlal
Nehru Technological Technological University)
APRIL6 2!171"
CERTI5ICATE
This is to certi rtify that the proj roject report entitled
8STU 8STUDI DIES ES ON
EXPANDED POLYSTYRENE CONCRETE9 submitted
by Shr-i N.C6
$/h/:/l/ &/gr-hi Re,,;6 Ann/,i Y/h/ri6 Illri Div;/6 $i--/3/ll; R/4 R/4;/ /n, /n, Ch. Ch. $0n $0ni: i:/ /
to the
'0:/r/ '0:/r/< < R/ng/r R/ng/r/< /< In-iIn-i--e -e 0
Engineering An, Techn0l0g; , H;,er/=/,,
in partial fulfillment for the
award of the degree of B. Tech in Civil Engineering is a bona fide record of project work carried out by them under my supervision The contents of this report, in full or in parts, have not been submitted to any other !nstitution or University for the award of any degree or diploma
Mr. V. Srinivasa Reddy
Associate "rofessor $epartment of %ivil &ngineering '0:/r/< R/ng/r/< In-i--e 0 Engineering Enginee ring /n, Te Techn0l0 chn0l0g; g;
E>-ern/l E>/4iner
Prof Dr. Mohammed Hussain
#ead of the $epartment $epartment of %ivil &ngineering '0:/r/< R/ng/r/< In-i--e 0 Engineering Enginee ring /n, Te Techn0l0g chn0l0g; ;
DECLARATION
'e declare declare that that this this project project report titled titled POLY POLYSTYRENE STYRENE CONCRETE CONCRETE9 9
8STUDIES ON EXPANDED
submitted in partial fulfillment of the
degree of B. Tech in Civil Engineering is a record of original work carried out by us under the supervision of Mr. V. Srinivasa
Reddy,
and has not
formed the basis for the award of any other degree or diploma, in this or any other !nstitution or University !n keeping with the ethical practice in reporting scientific information, due acknowledgements have been made wherever the findings of others have been cited
B/-ch7 '2
(hruti N% **+*A-*.) /ahakala Jagruthi 0eddy **+*A-*12) Annadi 3ashasri **+*A-*4) !lluri $ivya **+*A-*+) /ittapally 0amya **+*A-*+) **+*A-*+) %h /ounika **+*A-***)
AC%NO?LED'E$ENTS
'e have immense pleasure in e5pressing our thanks and deep sense of gratit gratitud udee to our guid guidee Mr. V. Srinivasa Reddy, Associate Professor, Department of ivil !ngineering, ".R.#.!.$ for his guidance throughout this project 'e also e5press our sincere thanks to Prof Dr. Mohammed Hussain, Head of the Department, ".R.#.!.$ for e5tending his help 6inall 6inallyy we e5press e5press our sincere sincere gratitu gratitude de to all the members members of faculty who contributed their valuable advice and helped us to complete the project report successfully
Shr-i NC (11 ( 1121A!1"# 21A!1"# $/h/:/l/ &/gr-hi Re,,; (1121A!1)# (1121A!1)# Ann/,i Y/h/ri (1121A!1*# Illri Div;/ (1121A!12# (1121A!12# $i--/3/ll; R/4;/ (1121A!12# (1121A!12# Ch. $0ni:/ (1121A!111#
STUDIES ON EXPANDED POLYSTYRENE CONCRETE ABSTRACT (tyrof (tyrofoam oam was was wide widely ly used used as food food and and manu manufac factu turin ringg prod produc ucti tion on as packaging tools to absorb vibration during handling and transportation process /illion tons of waste polystyrene is being produced in the world This will ultimately cause pollution and is harmful to eco system "olystyrene aggregate concrete is one of many lightweight material widely used in building of environmentally green homes $ue to light weight characteristics, it has potential to serve as aggregates replacement of coarse aggregates This project reports the results of an e5perimental investigation into the properties of hardened concrete bricks containing e5panded polystyrene beads by studying characteristic strength of concrete The beads are used as part of aggregate replacement in the mi5es Utili7ing waste polystyrene in concrete production not only solves the problem of disposal but helps in preserving natural resources "olystyrene possesses the property of high compressibility, and can be e5pected to provide very little restraint to volume changes of cement paste reducing fro due to applied loads as well as change in moisture content $ue to its technical properties, such as low weight, rigidity and formability, &"( can be used in wide range of applications The studies show that there is effect of particle si7e of the polystyrene beads on the compressive strength of the concrete concrete !t was observed that smaller the &"( bead si7e, greater the concretes compressive strength The project includes study of characteristic properties of &"( concrete with partial replacement of coarse aggregate with e8ual volume of chemically treated e5panded polystyrene at levels of *-, 1- and .-9 The properties of the bricks are mainly influenced by the content of polystyrene beads in the mi5 The results indicate that polystyrene concrete mi5 with certain portion of the beads may provide as a suitable alternative material in the construction industry %ey&ords' S-;r00/46 E>3/n,e, P0l;-;rene6 Ligh- @eigh- c0ncre-e6 c043reive -reng-h.
TABLE O5 CONTENTS
DESCRIPTION
%&0T!6!%AT& $&%:A0AT!;N A%
(T0A%T :!(T ;6 6!=U0&( :!(T ;6 TA>:&( A>>0&?AT!;N(@N;TAT!;N(@N;/&N%:ATU0& * !NT0;$U%T!;N ** =&N&0A: *+ >A%<=0;UN$ *1 ;>J&%T!?& * 6;A/&$ %;N%0&T& ** &5panded "olystyrene 6oam *+ &5truded "olystyrene 6oam *. /AT&0!A:( U(&$ *.* &5panded "olystyrene >eads *.** "hysical "roperties *.*+ /echanical "roperties *.+ ;rdinary "ortland %ement *.+* Applications *.++ "hysical "roperties *.1 6ine Aggregates *.1* "roperties of (and *. %oarse Aggregates *.* "roperties *.. 'ater *4 &"AN$&$ ";:3(T30&N& %;N%0&T& *4* %haracteristics of &"(% *4+ Applications of &"( %oncrete *41 Advantages And $isBAdvantages ;6 &"(% + :!T&0ATU0& (TU$3
1 &"&0!/&NTA: !N?&(T!=AT!;N
PA'E NU$BER
1* %;/"0&((!;N T&(T 1** (pecimen "reparation 1*+ Testing "rocedure 1+ N$T T&(T( 1+* 0ebound #ammer Test 1+** "reparation ;f (pecimen 1+*+ Testing ;f (pecimen 1++ Ultrasonic "ulse ?elocity Test 1++* "reparation ;f (pecimen 1+++ Testing ;f (pecimen 11 'AT&0 A>(;0"T!;N AN$ ";0;(!T3 T&(T 11* "orosity >y =ravity /ethod 11+ $ensity, Absorption And ?oids !n #ardened %oncrete A(T/ %4+) 111 A(T/ %*.C. (orpitivity Test T&(T 0&(U:T( . $!(%U((!;N( ;6 T&(T 0&(U:T( 4 %;N%:U(!;N( 2 (%;"& 6;0 6U0T#&0 ';0< 2*"0;>:&/( 6A%&$ '#!:& %A(T!N= 2+ %A0& AN$ T!"( $U0!N= /!!N= 21(%;"& 6;0 !/"0;?&/&NT C 0&6&0&N%&(
LIST O5 5I'URES 5I'URE
TITLE
PA'E NO.
LIST O5 TABLES TABLE
TITLE
PA'E NO.
ABBRE+ATIONS NOTATIONS NO$ENCLATURE
% D %ement contents
CHAPTER71 INTRODUCTION 1.1 'ENERAL %oncrete technology is growing and many advances and innovations have been made to cope with challenges of many construction aspects /any productions of lightweight concrete had been designed and among them are by the use of lightweight aggregates and artificial aggregates such as fly ash and slag "olystyrene is chosen due to its lightweight properties, with good energy absorbing characteristic and good thermal insulator leading mainly to nonBstructural applications :ightweight concrete have been chosen by many designers and contractors due to cost favors especially in highBrise buildings and longBspan bridges >asically, lightweight concrete is produced by introducing air inside the concreteE either by using gassing and foaming agent or using lightweight aggregate such as natural aggregate pumice, shale, slate) or industrial byBproduct palm oil clinker, sinteri7ed fly ash) or plastic granules styrofoam or polymer materials):ightweight aggregate clinker, pumice, shale, slate etc) and chemicals have been used by many researchers for the development of lightweight concrete
:ightweight concrete has remained a choice of designers due to the economy achieved in construction especially in the construction of highrise buildings
:ightweight concrete is prepared by either injecting a source of air within the concrete matri5 in the form of a foaming agent, or by using lightweight aggregates
The use of lightweight concrete increases the resistance of concrete structures to more dead loads at a reduced weight of the overall structure, thus enhancing the functionality, architectural outlook and erection
(imilarly, lager or longer precast concrete members can be prepared without adding to the overall weight of the concrete member
This results in a lesser amount of columns and pier elements in a construction system which is easier to place at the desired location with fewer joints
!n bridges, this may permit the use of an e5tensive bridge deck which can provide additional lanes
1.2 BAC%'ROUND (tyrofoam is a prevalent material for the use in thermal insulation of buildings during construction Apart from insulation, (tyrofoam is widely used as packing of food materials in storing and for protecting goods from vibration forces during the transportation phase
!t is treated as a waste product The cell structure of (tyrofoam consists of air up to FC9
This research study focuses on the performance of (tyrofoam packing material) as lightweight aggregate and its ability to reduce dead load without sacrificing the strength (tyrofoam particles were used to partially replace coarse aggregate %ompressive strength and unit weight of normal density concrete *G+G) were
used as benchmark for comparison with (tyrofoam lightweight concrete &5panded polystyrene beads are often used as the basis for packaging material This leads to a large amount of waste material which is not biodegradable This material could be granulated and used as a lightweight aggregate for concrete
1. OB&ECTI+E The objective of this paper is to prove the suitability of e5panded polystyrene embedded in reinforced concrete on the basis of cost reduction, %6% &mission, more indoor comfort, least energy needs, thermal conductivity, &mbodied energy, durability, sound insulation and earth8uake resistance and to provide a prospective design methodology best suited as per !ndian environment
* 6;A/&$ %;N%0&T& "olystyrene foams are good thermal insulators and are therefore often used as building insulation materials, such as in insulating concrete forms and structural insulated panel building systems =rey polystyrene foam, incorporating graphite has superior insulation properties They are also used for nonBweightBbearing architectural structures such as ornamental pillars) "( foams also e5hibit good damping propertiesE therefore it is used widely in packaging The trademark (tyrofoam by $ow %hemical %ompany is informally used for all foamed polystyrene products, although strictly it
should only be used for He5truded closedBcellH polystyrene foams made by $ow %hemicals
5I'71 TYPES O5 5OA$S
1..1E>3/n,e, 30l;-;rene 0/4
&5panded polystyrene &"() is a rigid and tough, closedBcell foam !t is usually white and made of preBe5panded polystyrene beads &"( is used for many applications eg trays, plates, bowls and fish bo5es ;ther uses include molded sheets for building insulation and packing material IpeanutsI) for cushioning fragile items inside bo5es (heets are commonly packaged as rigid panels si7e by C or + by C feet in the United (tates), which are also known as IbeadBboardI $ue to its technical properties such as low weight, rigidity, and formability, &"( can be used in a wide range of different applications !ts market value is likely to rise to more than U(*. billion until +-+- Typical values of thermal conductivity range from --1+ to --1C '@mK<) depending on the density of the &"( board The value of --1C '@mK<) was obtained at *. kg@m1 while the value of --1+ '@mK<) was obtained at - kg@m 1 according to the data sheet of
1..2 E>-r,e, 30l;-;rene 0/4
&5truded polystyrene foam "() consists of closed cells, offers improved surface roughness and higher stiffness and reduced thermal conductivity The density range is about +CD. kg@m 1 &5truded polystyrene material is also used in crafts and model building, in particular architectural models >ecause of the e5trusion manufacturing process, "( does not re8uire facers to maintain its thermal or physical property performance Thus, it
makes
a
more
uniform
substitute
for corrugated
cardboard
Thermal conductivity varies between --+F and --1F '@mK<) depending on bearing strength@density and the average value is M--1. '@mK<) 'ater vapour diffusion resistance ) of "( is around C-D+.- and so makes it more suitable to wetter environments than &"(
*. $ATERIALS USED (tandard "ortland cement was used in all mi5tures for this study, which met the re8uirement of fine and coarse aggregate were used that had been analy7ed with sieve analysis The coarse aggregate of si7e less than +-mm is used The polystyrene used for the study 6igure *) was in granular form, white in color, solid surface with diameter range between +B+. mm, very light in weight with densities between *. kg@m1B+kg@m1 /i5ing was done by using tap water
5I'72 POLYSTYRENE BEADS
1.".1 E>3/n,e, P0l;-;rene Be/,
"olystyrene is a vinyl polymer (tructurally, it is a long hydrocarbon chain, with a phenyl group attached to every other carbon atom "olystyrene is produced by free radical vinyl polymeri7ation, from the monomer styrene &5pandable polystyrene &"() meanwhile is polystyrene in raw beads being steamBheated, causing it to e5pand "olystyrene has been used mainly in cold countries to make concrete blocks for residential purposes "olystyrene is commonly injection molded, vacuum formed, or e5truded, while e5panded polystyrene is either e5truded or molded in a special process "olystyrene copolymers are also producedE these contain one or more other monomers in addition to styrene !n recent years the e5panded polystyrene composites with cellulose and starch have also been produced "olystyrene is used in some polymerB bonded e5plosives ">)
5I'7 $ANU5ACTURE O5 EXPANDED POLYSTYRENE
1.".1.1 Ph;ic/l Pr03er-ie
&"( has been a material of choice for over half a century because of its technical versatility, performance and cost effectiveness !t is widely used in many everyday applications where its light weight, strength, durability, thermal insulation and shock absorption characteristics provide economic, high performance products Ligh- ?eigh-
&"( is an e5tremely lightweight material which is not surprising considering it is comprised of MFC9 air This characteristic makes it ideal for use in packaging as it does not significantly add to the weight of the total product thereby reducing transportation costs &nergy consumption for transport fuel is also reduced and vehicle emissions minimi7ed D all contributing to lower global warming Dr/=ili-;
The e5ceptional durability of &"( makes it an effective and reliable protective packaging for a wide range of goods The cellular structure of &"( makes it dimensionally stable and therefore does not deteriorate with age &"( is also odourless and nonBto5ic
$0i-re Rei-/nce
&"( is a closed cell material and does not readily absorb water There is no loss of strength in damp conditions, making &"( ideal for coolBchain products The material is moisture resistant, so the highest hygiene re8uirements are met The ability of &"( to resist moisture also lends itself for use in fishing floats and marina buoys &ven when subjected to prolonged saturation in water, &"( will still maintain its shape, si7e, structure and physical appearance with only a slight reduction to its thermal performance Ther4/l Eicienc;
The superior thermal efficiency of &"( makes it ideal for packaging any product that is sensitive to temperature change "roducts enclosed in &"( containers can be maintained for long periods at temperature above or below ambient conditions and can be protected from sudden temperature changes that can occur in the transport through different climatic 7ones &5amples include fresh produce and seafood as well as pharmaceutical and medical products
Sh0c: A=0r3-i0n
&"( e5hibits e5cellent shock absorbing characteristics making it the first choice for packaging of a wide range of products including appliances, electronic products, computers and chemicals +er/-ili-;
&"( can be manufactured to almost any shape or si7e, or it can be easily cut and shaped when re8uired to suit any application &"( is also produced in a wide range of densities providing a varying range of physical properties These are matched to the various applications where the material is used to optimise its performance !n addition, &"( is also compatible with a wide variety of materials
E/e 0 Ue
6or building and construction applications, &"( is considered to be one of the easiest materials to install on site !t is normally supplied in sheet form however can also be molded into shapes or in large blocks 1.".1.2 $ech/nic/l Pr03er-ie
The mechanical properties of &"( foam depend primarily on density =enerally, strength characteristics increase with densityE however the cushioning characteristics of &"( foam packaging are affected by the geometry of the molded part and, to a lesser e5tent, by bead si7e and processing conditions, as well as density This by simple processing changes, without the need to redesign or retool 6or shock cushioning, the &"( packaging industry has developed typical cushioning curves for use by designers of &"( transport packaging (hock cushioning properties of &"( are not significantly affected by change in temperature Di4eni0n/l S-/=ili-;
$imensional stability is another important characteristic of &"( foam !t represents the ability of a material to retain its original shape or si7e in varying environmental conditions $ifferent plastic polymers vary in their reaction to the conditions of use and e5posure to changes in temperature and@or relative humidity (ome shrink, some e5pand and some are unaffected &"( offers e5ceptional dimensional stability, remaining virtually unaffected within a wide range of ambient factors The ma5imum dimensional change of &"( foam can be e5pected to be less than +9 Ther4/l Inl/-i0n
6or construction insulation applications the polystyrene foam industry has developed for 0igid %ellular "olystyrene Thermal !nsulation This standard addresses the physical properties and performance characteristics of &"( foam as it relates to thermal insulation in construction applications ?/-er A=0r3-i0n /n, +/30r Tr/n4ii0n
The cellular structure of &"( is essentially water resistant and provides 7ero capillarity #owever, &"( may absorb moisture when it is completely immersed, due to the fine
interstitial channels between the molded beads 'hile molded &"( is nearly impervious to li8uid water, it is moderately permeable to water vapor under pressure differentials ?apor permeability is determined by both density and thickness =enerally, neither water nor water vapors affect the mechanical properties of &"( ?/-er /=0r3-i0n 0 30l;-;rene 0/4
Although it is closedBcell foam, both e5panded and e5truded polystyrene are not entirely waterproof or vapor proof !n e5panded polystyrene there are interstitial gaps between the e5panded closedBcell pellets that form an open network of channels between the bonded pellets, and this network of gaps can become filled with li8uid water !f the water free7es into ice, it e5pands and can cause polystyrene pellets to break off from the foam &5truded polystyrene is also permeable by water molecules and cannot be considered a vapor barrier 'ater logging commonly occurs over a long period of time in polystyrene foams that are constantly e5posed to high humidity or are continuously immersed in water, such as in hot tub covers, in floating docks, as supplemental flotation under boat seats, and for belowBgrade e5terior building insulation constantly e5posed to groundwater Typically an e5terior vapor barrier such as impermeable plastic sheeting or a sprayedBon coating is necessary to prevent saturation
Che4ic/l Rei-/nce
'ater and a8ueous solutions of saltsand alkalis do not affect e5panded polystyrene /ost organic solvents are not compatible with &"( This should be taken into consideration when selecting adhesives, labels and coatings for direct application to the product All substances of unknown composition should be tested for compatibility Accelerated testing may be carried out by e5posing molded polystyrene to the substance at *+- D *- 6 U? radiation has a slight effect on molded polystyrene !t causes superficial yellowing and friability, but does not otherwise effect its physical properties Elec-ric/l Pr03er-ie
The volume resistively of molded polystyrene within the *+. D +. pcf density range, conditioned at 21 6 and .-9 rh is 5 *-*1 ohmBcm The dielectric strength is appro5imately +
%ement can be defined as the bonding material having cohesive L adhesive properties which makes it capable to unite the different construction materials and form the compacted assembly ;rdinary@Normal "ortland cement is one of the most widely used types of "ortland cement 1.".2.1 A33lic/-i0n
O #ighBrise >uildings, 0esidential, %ommercial L !ndustrial %omple5es O 0oads, runways, bridges and flyovers O $efense %onstruction O 6or heavy defense structures like >unkers O "reBstressed concrete structures
1.".2.2 Ph;ic/l 3r03er-ie
TABLE71 BIS SPECI5ICATIONS AND SDCC NOR$S O5 " 'RADE OPC
Sl.N0.
Decri3-i0n
Uni-
Re. / 3er IS7 122*7 1)
SDCC N0r4
A# CHE$ICAL CO$POSITION
* + 1 . 4 2
!nsoluble 0esidues!0) /agnesium ;5ide/g;) (ulphuric Anhydride(;1) :oss on !gnition:;!) :ime (aturation 6actor :(6) Alumina !ron ratio A@6) %hloride %!B)
9 9 9
1- /a5 +- /a5 4- /a5 +. /a5 +. /a5 when %1AP. L +2. /a5
9
1- /a5 when %1AQ. - /a5
1 /a5
9
-C-B*-+
-F-/in
9 9
-44 /in -*- /a5
**- /in --. /a5
B# PHYSICAL PROPERTIES
* + 1
(pecific (urface (oundness &5pansion) a) >y :eB%hatelier b) >y Autoclave (etting Time a) !nitial (et b) 6inal (et %ompressive (trength a) 1 days b) 2 days c) +C days
m+@kg ++. /in mm 9
+C- /in
*-- /a5 -C /a5
1- /a5 -+ /a5
/inute 1- /in /inute 4-- /a5
2- /in +.- /a5
/"a /"a /"a
+2 /in 12 /in .1 /in
1. /in . /in .C /in
1.". 5ine Aggreg/-e (S/n,# S/n, is
a naturally occurring granular material composed of finely
divided rock and mineral particles !t is defined by si7e, being finer than gravel and
coarser than silt S/n, can also refer to a te5tural class of soil or soil typeE ie a soil containing more than C.9 sandBsi7ed particles by mass) The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and nonB tropical coastal settings is silica silicon dio5ide, or (i;+), usually in the form of 8uart7 The second most common type of sand is calcium carbonate, for e5ample aragonite, which has mostly been created, over the past half billion years, by various forms of life, like coral and shellfish !t is, for e5ample, the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the %aribbean 1."..1 Pr03er-ie 0 /n,
0oundness and (phericity
(and is ubi8uitous !t makes up most beach and river deposits
(and is concentrated by selective transport
(and is left at beaches as the finer clay particles are washed out to sea
A medium si7ed river takes about a million years to transport a sand grain *-miles downstream
Transport does not do much to change the roundness and sphericity of the sand grains
'ork by
1.". C0/re Aggregr/-e
%oarse aggregate shall consist of naturally occurring materials such as gravel, or resulting from the crushing of parent rock, to include natural rock, slags, e5panded clays and shales lightweight aggregates) and other approved inert materials with similar characteristics, having hard, strong, durable particles, conforming to the specific re8uirements of this (ection %oarse aggregate for use in nonstructural concrete applications or hot bituminous mi5tures may also consist of reclaimed "ortland cement
concrete meeting the re8uirements of F-*B. 'ashing of this material will not be re8uired if the re8uirements of F-*B*+ for ma5imum percent of material passing the No +-- sieve can be met without washing 1."..1 Pr03er-ie Ch/r/c-eri-ic c0n-r0lle, =; 30r0i-; Deni-;
Apparent specific densityG $ensity of the material including the internal pores >ulk density dryBrodded unit weight) weight of the aggregate that would fill a unit volumeG affects the following concrete behaviorG mi5 design, workability, and unit weight A=0r3-i0n /n, r/ce 40i-re
Affects the following concrete behaviorG /i5Bdesign, (oundness, S-reng-h /=r/i0n rei-/nce S0n,ne
Aggregate is considered unsound when volume changes in the aggregate induced by weather such as alternate cycles of wetting and drying or free7ing and thawing result in concrete deterioration $epends onG porosity, flaws and contaminants "umiceB *-9 absorption) B no problem with free7ing and thawing :imestoneB breaks use smaller aggregate critical si7e) P/r-icle iFe
SiFe
Affects the following concrete propertiesG water demand, cement content,
microcracking =rading $epends onG proportions of coarse and fine aggregate AffectsG paste content cost economy), workability
1."." ?/-er
A general understanding of the role of water in the process of cement hydration is important The cement in the concrete needs water to hydrate and form %alciumB (ilicateB#ydrate %B(B#) which is the glue that holds the concrete together The water is chemically bound consumed) during the reaction with the cement at appro5imately +. pounds of water to every *-- pounds of cement Therefore, it could be said %&/& U(A B Technical >ulletin F* + that a water to cementitious materials ratio w@cm) of -+. is needed for the %B(B# and hydration products to be formed That, however, is not all of the water that is needed There is additional water that becomes physically bound between the cement hydrates !n order to have enough water to possibly enable complete hydration of the cement, appro5imately +- pounds of water to every *- pounds of cement is necessary %ombined, this e8uates to appro5imately . pounds resulting in a w@cm of -. !t should be noted that a concrete rarely gets the benefit of complete cement hydration typically because of the lack of physical access to the inner unhydrated cement particles and also due to lack the minimum re8uired curing that would be needed A properly proportioned concrete mi5 should possess these 8ualitiesG * Acceptable workability of the freshly mi5ed concrete + $urability, strength, and uniform appearance of the hardened concrete 1 &conomy ?h/- 3/r/4e-er 0 -he c0ncre-e /re /ec-e,G
'ith the addition of water to a load of concrete in e5cess of the design w@cm, the following performance characteristics will likely be negatively affectedG
%ompressive (trength
0esistance to cycles of free7ing and thawing
0esistance to damage from (ulfates in soil and water
"ermeability D and its associated impact to strength and various durability characteristics
/inimi7ing potential for corrosion of reinforcing steel
1.* E>3/n,e, P0l;-;rene C0ncre-e "olystyrene aggregate concrete is one of many lightweight, low strength materials with good energy absorbing characteristics "olyconcrete is lightweight concrete made with cellular polystyrene beads RparticlesS as aggregate Unlike aerated concrete, this re8uires autoclaving to obtain both lightness and strength !t can be used for both inBsite and preBcast components The lightweight aggregate can be made at the concrete works, using raw e5pandable polystyrene beads (ince polystyrene particles are uniform, and relatively course, the structure can range from that of noBlines concrete density 1-- kg@m or less) to that of fully compact concrete density *--- kg@m or more) 1.*.1 Ch/r/c-eri-ic 0 EPSC Per4e/-i0n ch/r/c-eri-ic7
Water absorption G 'ater absorption of foam concrete
decreases with a reduction in
density, which is attributed to lower paste volume phase and thus to the lower capillary pore volume The o5ygen and water vapour permeability of foam concrete have been observed to increase with increasing porosity and fly ash content
SorptivityG The moisture transport phenomenon in porous materials has been defined by
an easily measurable property called sorptivity absorbing and transmitting water by capillarity), which is based on unsaturated flow theory (orptivity of foam concrete is reported to be lower than the corresponding base mi5 and the values reduce with an increase in foam volume Rei-/nce -0 /ggreive envir0n4en-
6oam concrete mi5ture designed at low density taking into consideration of depth of initial penetration, absorption and absorption rate, provided good free7eBthaw resistance (ulphate resistance of foam concrete reveals that foam concrete has good resistance to aggressive chemical attack 5nc-i0n/l ch/r/c-eri-ic
6ire resistance
Thermal insulation
Ther4/l inl/-i0n
6oam concrete has e5cellent thermal insulating properties due to its cellular microstructure The thermal conductivity of foam concrete of density *--- kg@m1 is reported to be oneBsi5th the value of typical cementDsand mortar
5ire rei-/nce
6oam concrete is e5tremely fire resistant and well suited to applications where fire is a risk Test have shown that in addition to prolonged fire protection, the application of intense heat, such as a high energy flame held close to the surface, does not cause the concrete to spall or e5plode as is the case with normal dense weight concrete 1.*.2 APPLICATIONS O5 EPS CONCRETE Bil,ing Bl0c:G
>locks and panels can be made for partition and load bearing walls
They can be made with almost any dimensions
5l00r Scree,
&"( concrete can be used for floor screeds, creating a flat surface on
uneven ground and raising floor levels R00 Inl/-i0n
&"( %oncrete is used e5tensively for roof insulation and for making a
slope on flat roofs !t has good thermal insulation properties and because it is lightweight foamed concrete does not impose a large loading on the building R0/, S=7B/e
&"( %oncrete is being used road sub base on a bridge 6oamed
concrete is lightweight so that the loading imposed on the bridge is minimi7ed N0n -rc-r/l 4e4=er ch /
!nterior wall panels nonBload bearing walls), 6alse ceilings
Aesthetic decors
(un shades, %ustom made wardrobes, etc
1.*. AD+ANTA'ES AND DISAD+ANTA'ES O5 EPS CONCRETE
Disadvantages Advantages Weight
Light; down to 600kg/m3
Sensiti%e to most
Strength
Ranging rom ! to !0 "/mm!
petroleum products
Resistance
"ot suita#le to #e
to
used as prestressed
chemicals
Suita#le or Structural and
Field
non$structural mem#ers
Application
Less than most a%aila#le
s
lightweight concretes
Cost
Acoustic
concrete
&he #est among all other lightweight concrete
Starts to e%aporate
'urning without (ames
a#o%e 3000C
resistance Fire
)er* worka#le at low w/c
Resistance
ratio
Sta#le up to 30
Consistence or w/c 0+3!
minutes ater mi,ing
Worka#ilit*
-i, consistenc*
to 0+
&he #est among all other lightweight concrete
Less than normal concrete &hermal insulation
.ardening time o resh concrete
CHAPTER72 LITERATURE STUDY %urrently millions of tons of waste polystyrene are produced in the world This will ultimately cause pollution and is harmful to the ecosystem National and international environmental regulations have also become more infle5ible, causing this waste to become increasingly e5pensive to dispose Therefore, utilising waste polystyrene in concrete production not only solves the problem of disposing this ultraB light up to F.9 air) solid waste but also helps preserve natural resources "olystyrene aggregate concrete is one of many lightweight, low strength materials with good energy absorbing characteristics !t is well known for its good thermal and acoustic insulation properties leading mainly to nonBstructural applications including precast roof and wall panels and lightweight infill blocks P/r-0n6 12) !t has also been considered for use as a core material in sandwich panels, beams, and slabs "arton, *FC+), as a subBbase material for road pavements H/nn/6 1)) and also in floating marine structures B/g0n /n, Y/nn/6 1)* ) !n Japan, it has been used in the construction of sea beds and sea fences Y0hin0 e- /l.6 1! ) A study conducted by Perr; e-/.l (11# on mi5 details and material behavior of polystyrene aggregate concrete proved that strength and density are controlled by varying mi5 proportions
R/vin,r/r/
their study on the
properties of hardened concrete containing polystyrene beads Their results showed that the strength, stiffness and chemical resistance of polystyrene aggregate concrete of a constant density are affected by the water to cement ratio Another study
=; Bich0 e- /l. (11# found
that polystyrene aggregate
concrete is useful to absorb energy and to reduce contact loading loads during hard impact at low velocities 'ork was also carried out by the %ement and %oncrete Association of New ealand in *FF* which e5amined the strengths and some drying shrinkages of recycled &"( concrete The study highlighted difficulties in compaction and finishing of concrete with densities below *---kg@m1
H/4,/n (2!!!# in
a study reports that the use of polystyrene beads as
lightweight aggregates shows lightweight property that highlights the use of polystyrene aggregate concrete in nonBstructural applications The C/n/,i/n 50n,/-i0n Engineering $/n/l r, E,i-i0n has 3eciic rec044en,/-i0n where
structures have a greater risk of frost heave and in certain
cases these structures must be separated from the primary structure >uildings without basements are often supported on castBinBplace concrete piles with perimeter grade beams (ince foam insulation has a high compressive strength it cannot be used as a void former to absorb heave movement A proper minimum thickness of well drained and well compacted clean granular fill as well as foam insulation is re8uired under grade beams and it is a common practice to make reinforcing in grade beams symmetrical top and bottom such that some uplift load can be tolerated without risk of cracking S/=// /n, R/vin,r/r/
engineering properties of polystyrene "()
aggregate concrete by partially replacing natural coarse aggregate with e8ual volume of the chemically coated polystyrene at the levels of 1-, .- and 2-9 They found that compressive strength, unit weight and modulus of elasticity decreased and drying shrinkage and creep increased with increasing "( aggregate replacement in concrete B/= investigated the behaviour of light weight e5panded polystyrene concrete
containing silica fume and found that the rate of strength development increased and the total absorption values decreased with increasing in replacement levels of silica fume in concrete !t was also found that the strength of &"( concrete marginally increased as &"( bead si7e decreased and increased as the natural coarse aggregate si7e in concrete increased The S/r/,hiB/= e- /l. study covers the use of e5panded polystyrene &"() beads as light weight aggregate, both in concrete and mortar The mechanical properties of &"( concretes containing fly ash were compared to the results of concretes containing "ortland cement alone as the binder The compressive strength of the &"( concretes containing fly ash show a continuous gain even up to F- days, unlike that reported for "ortland cement in literature !t was also found that the failure of these concretes both in compression and split tension was gradual as was observed for the
concretes containing plastic shredded aggregates This study tested mi5tures with densities as low as 4--kg@m The results of compressive tests in the
$ile, e- /l. investigation confirmed the
presence of a particle si7e effect on the &"( concrete compressive strength since it was observed that the smaller the &"( bead si7e, the greater the concrete compressive strength, for the same concrete porosity /ost research on &"( concretes as mentioned above has shown a decrease in the durability performance and the engineering properties of concrete with increasing the amount of polystyrene aggregate in mi5tures and an increase in strength with smaller &"( bead si7e in concrete The studies on &"( concretes reviewed above have also shown that mi5tures produced using the ordinary vibration method will lead to a large number of particles floating upward and serious concrete segregation, resulting in &"( lightweight aggregate concrete with reducing its various performances This is due to the ultraBlight &"( particles and being 8uite weak A great deal of research has used super plasticisers and fly ash to increase the workability of the concrete Additives like these may not be readily available in developing countries An abundant natural resource in most countries should be tested as an alternative material to improve the resistance to segregation of &"( in concrete Use (tyrofoam in concrete material by utili7ing waste concrete can reduce construction costs, slowing the onset of the heat of hydration, lower density of concrete, and reduce the work load earth8uakes is smaller due to heavy concrete structures is reduced That in the end the e5ploitation of natural materials such as sand, gravel, and cement for building materials can be reduced /otivation to investigate the performance of sandwich beams of normal and lightweight concrete is to design structural elements that utili7e the most advantageous properties of two different concrete 8uality and they are in one section (andwich beams are used in applications re8uiring high bending stiffness and strength combined low weight(tudies on the use of truss system reinforcement of structural elements have been conducted by several researchers such as S/l40n e-. /l which uses steel trusses on the panel to reduce deflection shell Deh3/n,e e-./l. conducted e5perimental sandwich beam, which consists of a
triangular truss core faceBsheets, which have been casted with aluminiumBsilicon alloy
and silicon in brass to get macroscopic effective stiffness and strength sheet faceBsheets and tetrahedral core Li e-./l. studied a multiparameter optimi7ation procedure on the panel UltraBlightweight trussBcore sandwich ;ptimi7ation of improving structural performance of each panel in the case of multiple loading and minimi7e structural weight simultaneously %/=ir developed
a method to investigate the mechanical characteristics of the
1$ sandwich wall panel in shear and fle5ural static load, in order to understand the structural components (tudies on the use of reinforcement frame system on structural elements have been conducted by several researchers such as
S/l40n /n, Eine/,
trusses on the panel to reduce deflection shell
which uses steel
Deh3/n,e /n, 5lec: ,
conducted
e5perimental beam sandwich, which consists of a triangular truss core faceBsheets, whichhave been printed with aluminiumBsilicon alloy and silicon in brass to get macroscopic effective stiffness and strength of faceBsheets and tetrahedral core %0cher ?/-0n6 '04eF /n, Bir4/n6 presents
a theoretical approach to study several issues
related to the design of sandwich structures with a polymer frame reinforced with hollow core using a simple analytical model that describes the contribution to the stability of the structure is hollow at the core !n general, the research related to the utili7ation of waste styrofoam for use in beam structural elements for purposes of efficiency of use of natural materials in concrete construction and application of environmentally technological knowledge A series of e5perimental testing have been performed The concrete that filled with the 1-9 (tyrofoam grains is named with (tyrofoam 6illed %oncrete (6%B1-) P/r: /n, Chih0l4
use polystyrene as fine aggregate and has a less specific
gravity ranges from .+- to *-- kg@m1 has a very low compressive strength, which is in the range -2 /"a to 42 /"a These results are far from the minimum re8uirement of concrete to be used as structural concrete The need for water in the mi5ture is lower than design mi5E the e5cess water will cause segregation of the cement paste %oncrete mould compaction process cannot be performed conventionally for material that is light enough %ompaction process into the mould is done layer by layer by using the pressure of human hands %ompaction method using a vibrator is also not recommended in the
manufacture of lightweight concrete mi5tures with polystyrene aggregate "ark and %hisholm also showed that the mi5ture with a cement content of *--- kg@m1 are able to produce cement paste enough to wrap the aggregate and produce a good surface /eanwhile, %h/il showed appro5imately the same results, that the more the content of polystyrene in the mi5ture it will reduce the compressive strength of concrete >y using the ratio of polystyreneG sand V .G * and the cement content of 4-kg@m1 can generate compressive strength of *. /"a and density of *+-- kg@m1, so it can be said that the concrete has been produced can be used as a concrete structural and nonBstructural concrete $04-/Fi e-./l did
research on the durability of lightweight concrete epo5y
polystyrene in an environment with high salinity The results of /omta7i mention that within +*- days, the presence of polystyrene epo5y material in the concrete mi5 at high salinity environments can provide fairly good protection against the risk of corrosion of reinforcing steel, however, the nature B the mechanical properties of concrete decreased slightly due to the presence of epo5y polystyrene Another study conducted by B/=
e-./l
and 50n-e=0/ and A=ell/ the two
researchers are using pure &"( beads and recycled &"( beads are mi5ed with silica fume as the building blocks of concrete mi5es The results showed that the concrete mi5ture obtained has a specific gravity of between *.-- to +--- kg@m1 with compressive strength ranging from *- to +* /"a (ilica 6ume able to increase the initial compressive strength of concrete mi5 at the age of 2 days Bhi:h4/ e-./l conduct an e5perimental study on 0% >eams, which has been
damaged and repaired with epo5y resin 6rom their study, it has been concluded that material comes from epo5y can be used to repair the damaged structures, cheaper than to reconstruct the structure Another study conducted by
B/:h-i;/ri e-./l investigate
the influence of
e5panded polystyrene as a formwork on fire resistance of self compacting concrete (everal researchers studied the structural, physical and mechanical behaviour of polystyrene concrete They avoided vibration compaction during the manufacturing of "%) and compacted their mi5es by hand tamping to minimi7e the segregation of
polystyrene beads because of its low density The main aim of this investigation is to use polystyrene beads to produce (%B"%) which is a special type of concrete mi5ture characteri7ed by high resistance to segregation that can be cast without compaction or vibration , because it becomes levelled and compacted under its selfBweight S4/n concluded
that the mechanical properties of "%) increase with the
increase of its density and these properties are controlled by the water to cement ratio $/r/
also produced "%) with densities between ++-B4-) kg@m1 and compressive
strength between -2B+1)/"a, while modulus of rapture was between -1-14)/"a I4/il
studied the properties of hardened concrete bricks containing
polystyrene beads and he found that "%) is very prone to segregate where placing and compacting can be 8uite difficult using vibratory compaction techni8ues Also he found that the "%)bricks with densities less than *C--kg@m1 have very low strength which can be used as a nonBload bearing internal wall while the "%) with density of *44)kg@m1 have compressive strength of */"a) which is suitable to use as a load bearing internal wall %h/il studied the characteristics of "%) and he proved that the proposed mi5 is very reliable giving strength of up to +--kg@cm+ with low density Also he found very high mi5 workability at a very low water@cement ratio down to -1.) Annually, appro5imately 4-- million tons of rice paddy is produced Ch/n,r/e:h/r e- /l.6 2!! ) 6or every *--- kg of paddy milled, about +-- kg of husk is produced, and when this husk is burnt, about - kg of 0#A is generated %ook, *FC4) 0#A has F-DF.9 amorphous silica $e-h/6
12)
!t is highly porous,
lightweight and has a high surface area Dell/ e- /l.6 2!!2 ) /any previous researches showed that 0#A can be used successfully in other building materials such as bricks and blocks without any degradation in the 8uality of products N/l; /n, Y/in6 2!! R/h4/n6 1)
An intensive literature survey on light weight concrete has been carried out to seek references to the use of polystyrene in concrete mi5es, more than 1--- websites were visited over the internet, and nothing was directly related to the topic of this paper Accordingly e5tensive work is needed to e5plore all chemical, physical and structural properties An attempt has been made to e5plore, provisionally, the structural and physical behaviour, advantages and disadvantages of "olystyrene concrete
CHAPTER7 EXPERI$ENTAL IN+ESTI'ATION
.1 CO$PRESSION TEST The investigation is carried out to study the %ompressive (trength, (plit Tensile (trength and 6le5ural (trength of >acterial %oncrete A total of +- sets of cubes, each /+- and /4- grade concrete, are cast and tested to study the %ompressive (trength under a5ial compression a total of 4 sets of cylinders, each /+- and /4- grade concrete, are cast and tested to study the (plit Tensile (trength and a total of 4 sets of prisms, each /+- and /4- grade concrete, are cast and tested to study the 6le5ural (trength of concrete .1.1 S3eci4en Pre3/r/-i0n
;rdinary =rade %oncrete /+-) and #igh (trength =rade %oncrete /4-) mi5es are designed %ubes of *--mm 5 *--mm 5 *--mm are made as per !(G .*4B *FFF along with %ylinders of *.-mm 5 1--mm and prisms of *--mm 5 *--mm 5 .--mm are cast The cubes, cylinders and prisms are cast using with bacteria and without bacteria After casting, the specimens are demoulded after + hours and immediately submerged in clean fresh water of the curing tank After the completion of curing period the specimens are taken and kept under shade before testing .1.2 Te-ing Pr0ce,re
After the re8uired period of curing the cube specimens are removed from the curing tank and cleaned A set of cubes are tested for %ompressive (trength at 2, *, +C, 4- and F- days , cylinders are tested for (plit Tensile (trength at +C, 4- and F- days and prisms are tested for 6le5ural (trength at +C, 4- and F- days
.2 NDT -e- S-,ie 0n E-i4/-ing C043reive S-reng-h 0 C0ncre-e -hr0gh N0n De-rc-ive Technie
.2.1 Re=0n, H/44er Te.2.1.1 Pre3/r/-i0n 0 S3eci4en
%ubes were cast, targeting at different mean strengths 6urther, the cubes were cured for different number of days to ensure availability of a wide range of %ompressive (trength attained by these cubes (i7e of each cube was *.-W*.-W*.- mm .2.1.2 Te-ing 0 S3eci4en
* *- readings rebound numbers) were obtained for each cube, at different locations on the surface of the specimen + The cube was divided into grid blocks of e8ual spacing and *- points were marked at e8ual intervals for taking the 0ebound #ammer test 1 The cubes were then given a load of 2 N@mm+ as specified by the !( *11**) in the %ompression Testing /achine and the 0ebound ?alues were obtained The cubes were then loaded up to their ultimate stress and the >reaking :oad was obtained .2.2 Ul-r/0nic Ple +el0ci-; Te.2.2.1 Pre3/r/-i0n 0 S3eci4en
%ubes were cast, targeting at different mean strengths 6urther, the cubes were cured for different number of days to ensure availability of a wide range of %ompressive (trength attained by these cubes (i7e of each cube was *.-W*.-W*.- mm .2.2.2 Te-ing 0 S3eci4en
* 1 readings of Ultrasonic "ulse ?elocity U("?) were obtained for each cube + The cubes were then given a load of 2 N@mm+ as specified by the !( *11**) in the %ompression Testing /achine and the U("? were obtained
1 The cubes were then loaded up to their ultimate stress and the >reaking :oad was obtained The tables lists the $ead :oad on the specimen at the time of testing, the >reaking :oad, /ean 0ebound ?alue, /ean "ulse velocity value along with estimated %ompressive (trength as obtained by the %ompression Testing /achine
.. ?/-er /=0r3-i0n -e- /n, P0r0i-; -eThe aim of this study is to determine the total water absorption capacity and measure the volume of voids present in controlled and bacteria incorporated concretes of ordinary /+-), standard /-) and high strength /4- and /C-) grades as per A(T/ %4+B*1 The total 8uantity of water absorbed is related to the total open porosity, while the kinetics of the process depends principally on the distribution of the pore si7es This test also measures the capillary rise of water, the most common form of li8uid water migration into concrete which is inversely proportional to the diameter of the pores Absorption is the capacity of a sample to hold water while capillary is the rate at which the water fills the sample %oncrete cube samples of si7e *-- 5 *-- 5 *-- mm are casted and cured for +C days for testing $etermining the sorptivity of a sample in the lab is a simple, low technology techni8ue, all that is re8uired, is a scale, a stopwatch and a shallow tub of water The samples *-- 5 .- mm si7e cylindrical specimens are preconditioned to a certain moisture condition, either by drying the sample for 2 days in a .-X% oven (orptivity measures the rate of penetration of water into the pores in concrete by capillary suction !t is also a measure of the capillary forces e5erted by the pore structure causing fluids to be drawn in to the body of the material !t provides a relative measure that combines pore si7e diameter and number of pores present ..1 P0r0i-; =; -he gr/vi-; 4e-h0,
This method consists of saturating the concrete sample of si7e *-- 5*-- mm cube ;nce it is fully saturated, it is weighted with centigram precision and its volume ? is determined by weighing Then, the sample is submitted to moderate oven drying at a temperature of 4- Y+ X% The drying is stopped when the weight of the sample remains constant The weight of the dried sample is obtained after +* days of drying "orosity, p is then determined using the following formulaG
/sat B /dry "V BBBBBBBBBBBBB Zw ? 'here Zw the unit mass of water * g@cc), ? is the volume of sample *-- 5 *-- 5*-mm1) , /dry and / sat denote the weight of the dried and fully saturated samples, respectively The porosity can be e5pressed either as a fraction or as a percentage ..2 Deni-;6 A=0r3-i0n /n, +0i, in H/r,ene, C0ncre-e (AST$ C*2#
6or measuring the voids and absorption of the hardened concrete samples, the A(T/ %4+ +--4) standard test method was used A balance, water bath, and container suitable for immersing the specimen are needed for performing the test After the *--5 *-- mm cube samples were cured in the curing room for the re8uired time, three samples were removed from the curing room and put into an oven at *--X % for + hours The dried samples were taken from the oven and put on the cabinet to cool for about 1- minutes The samples were then weighed / a) using a balance with an accuracy within --* grams The samples were submerged in the water tank for + hours !t should be noted that if warm samples were put in the tank, they might crack, so they were allowed to cool first for hours After + hours, the samples were removed from the water tank and their surface was dried with a paper towel to obtain a saturated surface dry (($) condition The weight / b) of the (($ samples was measured !n the ne5t step, the samples were put into a water bath with boiling water for . hours The total time that the samples were in the water bath was about si5 and half hours, including F- minutes for heating up The samples were removed from the boiling water and left in the laboratory environment on the cabinet) for *+ hours The weight of the samples was measured / c) ;n the same day, the apparent weight of each sample / d) was measured by immersing the samples in the water using a hanging balance Using the measured weights /a to /d) the absorption after immersion, the bulk density, the apparent density, and the volume of permeable voids can be calculated / bB/a 'ater Absorption %apacity 'A%) V BBBBBBBBBB 5 *-/a /a >ulk density V g * V BBBBBBBBBB 5 Z /cB /d
/a Apparent density Vg+ V BBBBBBBBBB 5 Z /aB /d
g + B g* ?olume of permeable voids ?"?) V BBBBBBBBB 5 *-g+ 'hereG /a V mass of ovenBdried sample in air, kg / b V mass of surfaceBdry sample in air after immersion, kg /c V mass of surfaceBdry sample in air after immersion and boiling, kg /d V apparent mass of sample suspended in water after immersion and boiling, kg g* V bulk density, dry kg@m 1) and g+ V apparent density kg@m1) ZV density of water *--- kg@m 1) The rate of water absorbed into concrete through the pores gives important information about the microstructure and permeability characteristics of concrete &5perimental results show that the depth of water absorbed into concrete increases linearly with respect to the s8uare root of wetting time "arrott *FF+) !n terminology, the sorptivity is the change in volume of water absorbed per unit area against the s8uare root of time %laisse et al *FF2) 'ater absorption and sorptivity can suggest useful data regarding the pore structure of the concrete The water absorption was determined on *--mm cubes as per A(T/ %B4+ by drying the specimens in an oven at a temperature of *-. - % to constant mass and then immersing in water after cooling to room temperature The specimens were taken out of water at regular intervals of time and weighed The process was continued till the weights became constant fully saturated) The difference between the water saturated mass and oven dry mass e5pressed as a percentage of oven dry mass gives the 'ater Absorption %apacity 'A%) The 'ater Absorption %apacity 'A%) of concrete is a measure of the pore volume or porosity in hardened concrete, which is occupied by water in saturated condition The porosity obtained from absorption tests is designated as effective porosity !t is determined by using the following formula &ffective "orosity V ?olume of voids @ >ulk volume of specimen) 5 *-The volume of voids is obtained from the volume of the water absorbed by an oven dry specimen or the volume of water lost on oven drying a water saturated specimen at *-. % to constant mass The bulk volume of the specimen is given by the difference in mass of the specimen in air and it[s mass under submerged condition in water
T/=le 2 Dr/=ili-; Cl/iic/-i0n / 3er AST$ C *2
%lassification &5cellent =ood Normal /arginal >ad
?olume of "ermeable ?oids ?"?)
'ater Absorption %apacity
9 by volume) P* *B*4 *4B*2 *2B*F Q*F
9 by weight) P. .B4 4B2 2BC QC
.. AST$ C1"" S0r3-ivi-; Te-
$etermining the sorptivity of a sample in the lab is a simple, low technology techni8ue, all that is re8uired, is a scale, a stopwatch and a shallow tub of water The samples *-- 5 .- mm si7e cylindrical specimens are preconditioned to a certain moisture condition, either by drying the sample for 2 days in a .-X% oven The sides of the concrete sample are sealed, typically with electrician[s tape or by sealant while the suction face and the face opposite it were left unsealed %ylindrical concrete specimens were placed on a filtered support sponge) so that the water level was *-Y* mm above the inflow face as shown in 6ig2*C The sample is immersed to a depth of .B*- mm in the water then the initial mass of the sample and time of start are recorded The procedure of recording mass of the sample was repeated, consecutively, at various times such as *. min, 1- min, * hr, + hr, hr, 4 hr, + hr, C hr and 2+ hr The gain in mass per unit area over the density of water !) is plotted versus the s8uare root of the elapsed time \t) The slope of the line of best fit of these points ignoring the origin) is reported as the sorptivity coefficient k) The rate of water absorption or sorptivity k), is the slope of !B \t graph m @ min *@+ or kg@ m+ @ \ min) 6or one dimensional flow, it can be stated that #all, *FCF)G ! V k 5 \t 'here k is sorptivity coefficient and ! V '@ A 5 d) ' V the amount of water absorbed in kg AV Area of the c@s of the specimen that is in contact with water m +) dV density of the medium in which the specimen was dipped *--- kg@m 1 in case medium is water)
>ecause of small initial surface tension and buoyancy effects, the relationship between cumulative water absorption kg@m+) and s8uare root of e5posure time t
-.
) shows
deviation from linearity during first few minutes Thus, for the calculation of sorptivity coefficient, only the section of the curves for e5posure period from *. min to 2+ hrs, where the curves were consistently linear, was used for the calculation of sorptivity
5ig E>3eri4en-/l Se-3 0r S0r3-ivi-; Te-
CHAPTER 7 TEST RESULTS
CHAPTER7" DISCUSSIONS O5 TEST RESULTS
CHAPTER7* CONCLUSIONS
CHAPTER7) SCOPE 5OR 5URTHER ?OR%
).1 PROBLE$S 5ACED ?HILE CASTIN' There are so many problems faced while casting the cubes which includeG •
6irstly we considered mi5 proportion based on weight As (tyrofoam is light weight much more 8uantity of (tyrofoam is re8uired for casting one single cube not only that as (tyrofoam occupies whole space binding property will be less
•
which affects strength which decreases drastically 'e also found that (tyrofoam is segregating as the (tyrofoam has smooth finishing binding property of mi5 is reducing
•
1ol*concrete is made #* mi,ing the lightweight aggregate with cement2 sand and water in a con%entional mi,er+ 1ol*st*rene #eads occup* much o the %olume #etween 600kg/m and 400kg/m where compressed aggregate occupies 60$4052 nearl* all the remaining space #eing lled #* the mortar+ Since this mortar determines the mechanical properties o the material it generall* has high cement content+ &he consistenc* o resh 1ol*concrete is not ade7uatel* measured #* means o the tests generall* emplo*ed or normal concrete+ &he di8erences arise rom the high proportion o the %er* regular aggregate2 which gi%es a mi, that
•
is lean and not %er* cohesi%e2 #ut o8ers little resistance to (ow+ Fresh 1ol*concrete contains a high proportion o spherical aggregate2 and is not %er* cohesi%e9 it has a crum# like consistenc*+ )arious tests or consistence or worka#ilit* has #een applied to it2 #ut the consistenc* categories oten applied
to normal concrete ha%e #een ound to #e generall* inapplica#le+
).2 CARE AND TIPS DURIN' $IXIN' 6or stronger concrete, increase the sand used and decrease the (tyrofoam by the same amount Add the "ortland cement and sand to the water and mi5 well to create a soup This should be a very wet consistency, not usual for cement because the polystyrene will soak up a large amount of the water (tyrofoam is e5tremely flammable, and releases a to5ic gas called styrene when burnt !t is unknown at this time whether mi5ing it with cement would retard this 8uality sufficiently to make a safe substance to use on the inside of home
7.3 SCOPE FOR IMPROVEMENT &his paper has e,plored the characteristics o new lightweight concrete consisting o pol*st*rene2 sand2 cement and water+ &hrough this paper it has #een pro%en that proposed the proposed mi, is %er* relia#le gi%ing strength with a low densit*+ &he mechanical and chemical properties ha%e2 also2 #een discussed in order to stud* the #eha%ior o pol*st*rene under di8erent en%ironments :i+e+ eld usage+ &he mi, worka#ilit* is %er* high at a %er* low water/cement ratio :down to 0+3+ A new method or designing 1ol*concrete mi,es has #een introduced in a simple2 *et practical and tangi#le wa*+ &his work can #e considered a new line o research or lightweight concrete as the mi,ing method is %er* simple2 relati%el* ine,pensi%e and does not need comple, machiner* s*stems+
1ermea#ilit* Structural #eha%ior A#sorption2 ree=e and thaw dura#ilit* A#rasion2 and corrosion o steel reinorcements+ Compaction techni7ues or ull scale applications
&he mentioned tests are essential to #e carried out #eore the use o 1ol*concrete in structural mem#ers+
CHAPTER7 RE5ERENCES * >ischoff "# et al, ]"olystyrene Aggregate %oncrete (ubjected to #ard !mpact[, "roceedingsB!nstitution of %ivil &ngineers, "art +G 0esearch and Theory, ?ol CF, *FF-, pp ++.B+1F + >ungey J# et al, Testing of %oncrete in (tructures, %hapman and #all, U<, *FF4 1 #amdanA, uilding 0esearch Association of New ealand, *FFF 2 "arton =/ et al, ]"olystyrene >ead %oncrete "roperties and /i5 $esign[, /aga7ine of %oncrete 0esearch, ?ol 1, No 1, *FC+, pp *.1B*4* C "erry (# et al, ]/i5 $etails and /aterial >ehavior of "olystyrene Aggregate %oncrete[, /aga7ine of %oncrete 0esearch, ?ol 1, No *., *FF*, pp 2*B24 F 0avindrarajah et al, ]"roperties of #ardened %oncrete %ontaining Treated &5panded "olystyrene >eads[, %ement and %oncrete %omposites, ?ol *4, No , *FF1, pp +21B+22 *- 0iley /A, ]/i5 $etails and /aterial >ehavior of "olystyrene Aggregate %oncrete[, /aga7ine of %oncrete 0esearch, ?ol 1, No *.., *FF*, pp C2B F+ ** (abaa, > and 0 ( 0avindrarajah, *FF2 &ngineering properties of lightweight concrete containing crushed e5panded polystyrene waste !nG /aterials research society, fall meeting, symposium //, advances in materials for cementitious compos, >oston, U(A
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