Strength of Mortar and Concrete as Influenced by Rice Husk Ash: A Review

Transcription

1 World Applied Sciences Journl 19 (10): , 01 ISSN IDOSI Pulictions, 01 DOI: /idosi.wsj Strength of Mortr nd Concrete s Influenced y Rice Husk Ash: A Review M.R. Krim, M.F.M. Zin, M. Jmil, F.C. Li nd M.N. Islm 1 Universiti Kengsn Mlysi, Mlysi Regionl Technology Support Centre, Sik Kimi Sdn Bhd, Mlysi 3 Dhk University of Engineering nd Technology, Gzipur, Bngldesh Astrct: Due to the pozzolnic rectivity, rice husk sh (RHA) is used s supplementry cementing mteril in mortr nd concrete nd hs demonstrted significnt influence in improving the mechnicl nd durility properties of mortr nd concrete. It hs economicl nd technicl dvntges to use in concrete. In this pper, criticl review on the influences of RHA on the strength of mortr nd concrete re minly presented. In ddition, properties nd pozzolnic ctivity of RHA, dvntges nd disdvntges of supplementry use of RHA in mortr/concrete re mentioned here. Bsed on the ville documented literture, it cn e concluded tht RHA could e used s supplementry cementing mteril up to certin level of replcement (out 0-30% of inder) without scrificing strength of concrete. Proper consumption of these RHA contriutes in solving environmentl pollution nd production of cost-effective concrete; it cn lso ply vitl role for the production of sustinle concrete. Key words: Rice husk sh % Mortr % Concrete % Pozzolnic ctivity % Compressive strength % Tensile strength INTRODUCTION utiliztion of industril nd iogenic wstes s supplementry cementing mterils hs ecome n The use of industril nd iogenic wstes in concrete integrl prt of concrete construction. During recent s supplementry cementing mterils is the present vitl decdes, mny reserches hve een conducted for using issue to otin sustinle environmentl solution, the (i) different types of gro-wste shes such s rice sve energy nd nturl resources. Some of the commonly husk sh [1-6], gsse sh [7], plm oil fuel sh [8-11] (ii) used supplementry pozzolnic nd cementing mterils the industril y products ground grnulted lst re rice husk sh (RHA), silic fume, ground grnulted furnce slg nd fly shes s cement replcement lst furnce slg, fly sh nd sh from timer etc. mterils [1-0]. Their utiliztion not only improves These wstes cn e found s nturl mterils, properties nd durility of concrete, ut lso mkes it y-products or industril wstes; these mterils re lso cost effective nd environment-friendly [3-6; 1-8]. otined with requiring low cost, energy nd time. Nowdys, rice husk is generted from rice processing Unfortuntely, hving technicl enefits, most of those industries s mjor griculturl y-product in mny prts wstes re dumped into environment without ny of the world, especilly in developing countries. Aout commercil return. In consequence, environmentl 500 million tons of pddy is produced in the world pollutions re incresed dy y dy. However, RHA, n nnully. Rice husk is the outer covering of this pddy ville wste mteril in the developing countries, is [9]. The sh otined y urning this rice husk is known y-product mteril otined from the comustion of rice s RHA. As wste mteril, rice husk is produced in husk. It consists of non-crystlline silicon dioxide (SiO ) griculturl nd industril processes. After incinertion, with high specific surfce re nd high pozzolnic only out 0% weight of rice husk re trnsformed to rectivity. Thus, due to growing environmentl concern RHA [30]. Still now, there is no effective/useful nd the need to conserve energy nd resources, ppliction of RHA nd is usully dumped into wter Corresponding Author: M.R. Krim, Deprtment of Civil nd Structurl Engineering, Universiti Kengsn Mlysi (UKM), Selngor, Mlysi. Mo: , Fx:

2 strems or s lndfills cusing environmentl pollution of sving step ut lso hs technicl/engineering enefits. ir, wter nd soils. The use of this y-product is n Sustntil energy nd cost sving cn e mde y environmentl friendly method of disposl of lrge using this wste mteril s prtil replcement for the quntities of mteril. energy-intensive OPC. Therefore, sed on the pulished It is well known tht concrete hs gined populrity litertures this pper summries - different properties of in the construction industry due to its stisfctory RHA nd its effects on mortr nd concrete; strengths performnce in strength requirements, its esiness in development of mortr nd concrete contining RHA; construction nd etter durility in norml environment. pozzolnic ctivity of RHA; enefits of supplementry However, ordinry Portlnd cement (OPC) is most use of RHA in cement nd concrete - to encourge importnt ingredient for concrete construction of ny type reserchers, construction compnies s well s owner for of structures. Nowdys, 5 illion tons of concrete is the consumption of RHA s supplement of cement nd produced nnully nd cement production is expected to ingredient of concrete to chieve the gol of sustinle rise to nerly illion tons y yer 010. The production concrete. of 1 ton of cement contriutes to out 1 ton of CO into the tmosphere [31]; pproximtely 7% world s cron Rice Husk Ash nd its Properties: Rice husk, siclly dioxide (CO ) emission is ccountle for production n griculturl residue, is otined from rice processing of OPC [3]. The present crucil issue - the glol mills of the developing countries. Only smll mount of wrming - is cused for the production of greenhouse produced husk is used s fuel in rice mill nd electricity gses (CO ). During the cement production, in ddition to generting power plnt. After urning rice husk, the RHA CO emissions, excess fuel is required for the urning of is produced s y-product, out 0% of its originl OPC clinker t tempertures round 1400 C [33]. This CO weight [1]. The unurnt rice husk contins out 50% emission cn e reduced y improving the cellulose, 5-30% of lignin nd 15-0% of silic; urning mnufcturing/production process of OPC. The utiliztion the former two components leves ehind silic sh [41]. of supplementry cementing mterils - nturl pozzolns, When rice husk is urnt t tempertures lower thn 700 C, slg, fly sh, silic fume, metkolin etc. - in concrete it shows cellulr microstructure which is highly rective production is one of the solutions to reduce the cement [36, 4]. RHA is highly pozzolnic mteril; it contins content s well s CO [9]. non-crystlline silic nd high specific surfce re Recently, the interest for utiliztion of wste mterils tht re ccountle for its high pozzolnic rectivity. in cement or concrete hs een incresed significntly. The high silic content in the form of non-crystlline or Besides, during the 0th century, the development nd morphous silic of RHA is dependent on the urning use of lended cements incresed rpidly in the concrete tempertures; 95% silic could e produced fter heting construction. A rising trend towrds the use of wste t 700 C for 6 hours [3]. During the growth of rice, it mteril - RHA, Fly sh, silic fume, slg, plm oil fuel sh sucks up silic from the soil nd incorportes it into its - in concrete s supplementry cementitious mterils structure [43]. A high concentrtion of silic, generlly hve een oserved in the construction industry. more thn 80-85%, is contined in rice husk - the outer The griculturl y-product (wste), RHA, hs lredy covering of the grin of rice plnt [44]. As shown in een proved s pozzolnic mteril [6, 34-35]; more Tle 1, the prticle size of RHA rnges from 5 to 10 µm; ttention is now given to use this pozzolns in cement or the specific grvity rnges from.0 to.4; nd the specific concrete, since its contriution generlly improves surfce re vried from 0 to 50m /kg. When rice husk is the properties of the lended cement nd concrete [36]. urnt into sh it fulfills the physicl chrcteristics Thus, in recent decdes, RHA hs een used s OPC nd chemicl composition of minerl dmixtures. replcement mteril in concrete industries [37-40]. However, pozzolnic ctivity of RHA is influenced y: (i) The utiliztion of RHA in ternry lend (OPC, RHA nd silic content, (ii) silic crystlliztion phse nd (iii) size fly sh) produces etter mortr strengths t the low nd surfce re of sh prticles, in ddition, sh must replcement level of RHA. With the low replcement of up contin only smll mount of cron [45]. Even for to 0% of pozzoln, the mortr contining these pozzolns higher urning temperture with some crystlline silic, reduces porosity [36]. Solution of disposl prolem of rective RHA could e otined y fine grinding [46-47]. these wstes nd production of economic concrete In order to ensure the qulity of sh, suitle could e ssured y their proper consumption. incinertor/furnce s well s grinding method is required Hence, utiliztion of RHA in concrete is not only cement for urning nd grinding rice husk. The presence of 150

3 Tle 1: Chemicl nd physicl properties of RHA (Wt. %) Chemicl properties of RHA SiO Al O Fe O CO MgO SO N O K O LOI Reference [] [34] [35] [36] [41] [4] Chemicl properties of OPC [34] [35] [36] Physicl properties of RHA 3 Mteril specific grvity(gm/cm ) Men prticle size (µm) Bline Fineness Reference.30 ; (cm /gm); 5750(cm /gm) [] (m /kg) [34] (cm /gm) [36] [41] (m /kg) nitrogen sorption [4] Physicl properties of OPC (cm /gm) [] [10] (cm /gm) [7] (m /kg) [34], - RHA otined from electric power sttion nd rice mill respectively unurnt cron cn dversely ffect the rectivity. greter strength thn tht of control concrete s well s Besides, durtion nd type of incinertion re the RHA (with verge prticle size of 95 µm) lended importnt prmeter influencing the rectivity of RHA s concrete t level of 10% replcement of RHA [35]. pozzolns [48]. The highest improvement in compressive strength for Menwhile, typicl chemicl composition nd the ultr fine RHA mixed concrete ws otined similr to physicl properties of RHA re given in Tle 1. It is RHA (verge prticle size of 95 µm) -lended concrete for oserved from this tle tht RHA contins lrge mount RHA content of 10% t 90 dys. The compressive of silic, more thn 80%, which is n effective constituent strength t replcement of 0% RHA t 90 dys ecomes for pozzolnic ctivity. Most of the shes show lower pproximtely equivlent with control concrete t loss of ignition property. Specific grvity is lso lower the sme ge. These positive results of ultr fine thn OPC; fineness of RHA is much greter thn tht of RHA-lended concrete otined due to the rpid OPC which is importnt for production of denser nd consumption of C(OH) produced during hydrtion of durle concrete. The RHA with lower vlue of loss of Portlnd cement t erly ges re ssocited to the high ignition nd higher vlue of surfce re cn result the pozzolnic rectivity of ultr fine RHA. As result, the production of reltively higher strength pozzolns [48]. hydrtion of cement is ccelerted nd lrger volumes of rection products re produced. Besides, the prticle Fineness Effect of RHA on the Concrete Strength: Similr pcking density of the lended cement is improved y to other hydrulic cement, the rectivity of rice husk sh fine RHA prticles, directing to reduced volume of lrger cement extremely depends upon the specific surfce re pores in the cement pste [1]. At higher ges (90 dys), nd or prticle size. The hydrtion strts t the surfce of the RHA concrete hd higher compressive strength in cement prticle; the rte of hydrtion depends on the comprison with tht of concrete without RHA nd the fineness of cement nd for rpid strength development, highest vlues of compressive strengths were chieved in fineness is importnt fctor [49]; similrly fineness of concretes with 0% RHA. The long term compressive RHA is vlule property for strength of lended strength of the concretes with RHA is higher due to the concrete. The ultr fine RHA mixed concrete produces filler effect of the smller prticles in the mixture [4]. 1503

4 On the other hnd, efore urning, chemicl tretment of rice husk ws performed y Sls et l. [5] to improve the effectiveness of RHA. They concluded tht pretreted sh shows etter mechnicl nd durle properties of concrete thn tht of ordinry RHA (produced y conventionl incinertion) mixed concrete s well s OPC concrete. These eneficil results re otined due to high content of morphous silic in the chemiclly treted RHA. They lso suggested tht this pretreted RHA could e used s supplement of OPC for the production of high performnce concrete. Besides, Fig. 1: Prticle size distriution curves of OPC nd RHA Dkroury nd Gsser [5] used RHA to the OPC in the [34]. production of high strength, low permeility concrete; for use in ridges, mrine environments nd nucler Nonetheless, properties of light weight ggregte power sttion. RHA hs een used y Skr [39] s prtil produced from RHA re enhnced with incresing replcement (5, 10 nd 15%) of cement to produce hevy fineness of RHA [1]. A prticle size distriution is shown weight concrete. He investigted different mechnicl in Figure 1; smller prticle size is oserved in RHA thn properties - compressive, tensile, flexurl nd ond tht of OPC tht is importnt for strength chievement. strengths; nd modulus of elsticity- physicl, shielding nd durle properties of hevy weight concrete Supplementry Use of RHA in Concrete: The use of mde with RHA nd found good results thn tht of RHA in cement or concrete s supplementry cementing OPC concrete. RHA ws produced y new technique mteril hs een incresed recently. Supplementry use (Tored rector) with control comustion of Egyptin rice of RHA in cement or concrete is not new technique ut husk in reserch y Nehdi et l. [53]. They investigted it ws strted since erly 1970 [50]. RHA hs een used in the physicl, mechnicl nd durility properties concrete s high s 30% y weight of OPC without ny (resistnce to surfce scling, chloride penetrility) of dverse effect on compressive strength nd permeility concrete mde with this sh nd found etter result thn properties [34]. It ws used y 10-0% replcement of tht of reference concrete s well s concrete from OPC to produce high strength concrete s much s high silic fume. They lso compred their result with other strength of 70 MP [41]. Besides, the properly urnt nd study (in which RHA produced y Fluidized ed ground rice husk cn e used s pozzoln in cement technology in United Stte) nd found significntly production [34, 36]. The incorportion of pozzolns such greter performnce of concrete properties. Chindprsirt s RHA, plm oil fuel sh nd fly sh re very eneficil et l. [1] used RHA to produce light weight ggregte to the performnce of mortr in terms of chloride nd otined etter results in terms of expnsion nd resistnce. In ddition, porosity nd chloride induced soluility nd disintegrtion. Besides ordinry concrete, corrosion resistnce of mortr re significntly improved RHA ws included in self-consolidting high performnce with the use of RHA [36]. Blck RHA ws used to concrete; test results show tht compressive strength, investigte the sulfte resistnce of concrete s Portlnd ultrsonic pulse velocity nd electricl resistivity cement Type 1 replcement t the levels of 0%, 10%, 30% incresed wheres the wter sorption nd totl porosity nd 50% y weight of inder. The study confirms tht decresed with lower w/ rtio nd higher RHA content ground lck RHA cn e pplied s pozzolnic mteril [6]. to concrete nd lso improves resistnce to sodium In contrst, RHA sed snd-cement lock ws sulfte ttck []. However, Bsh et l. [51] ws used prepred in reserch y Lertstitthnkorn et l. [5] to RHA to investigte the stiliztion property of soil nd investigte the het gining property of uilding; test they found tht RHA reduces the plsticity, decreses results show tht it performed etter thn tht of ordinry mximum dry density nd increses optimum moisture cly rick. Bsed on the literture, RHA hs een used content of soil; properties of soil improves t 15-0% in concrete s supplement of cement for out 40 yers. replcement of RHA. The use of RHA in the ternry lend All of these reserchers found etter performnce of with OPC nd fly sh performs significnt improvement concrete in terms of strength, chemicl nd durility of strength t low replcement level t the lter ge [36]. properties. Therefore, supplementry use of this wste 1504

5 Tle : Compressive strength of RHA mixed cement mortr Compressive strength (MP) t dys: RHA:OPC W/B rtio Reference 00: [34] 05: : : : : : : : [35] 05: ; ; ; : ; ; ; : ; ; ; : ; ; ; 4.8 RHA pssing #00 sieve; RHA pssing #35 sieve mteril up to certin limit is now one of the solutions of W/C rtios, high vlue of compressive strength of for fulfilling the present demnd of cement, production of mortrs ws investigted y Dkroury nd Gsser [5] economic concrete nd disposl of rice husk. It could e y using 30% RHA s replcement of prt of cement; noted tht most of the reserch performed sed on the this percent could e considered optimum. Besides, singulr replcement of OPC y RHA. Thus, ternry lend mximum mortr strength ws otined y 10 percent of RHA with slg, fly sh, plm oil fuel sh or the nturl RHA replcement y Givi et l. [35]. Srswthy nd Song pozzolns cn e further studied. Besides, during the [55] lso concluded tht t 5% optimum RHA cement mnufcturing process, the incorportion of RHA replcement level etter performnce of concrete in cement cn e investigted. properties could e oserved. In ddition, Sfiuddin et l. [6] suggested tht 15% replcement could e the optimum Compressive Strength of RHA Blended Mortr nd limit. Mhmud et l. [56] lso reported tht 15% cement Concrete: Compressive strength is the most vlule replcement y RHA is n optiml level for chieving property of concrete, lthough in mny prcticl cses mximum strength. other chrcteristics, such s durility, impermeility The compressive strengths of RHA lended nd volume stility, my in fct e more importnt [49]. concrete specimens, s otined from different It is well known tht the clcium silicte hydrte (C-S-H) litertures, re presented in Tle 3. It cn e seen from gel is the min source of strength of cement. After the Tle 3 tht the compressive strength increses ddition of RHA to the fresh cement, it chemiclly rects with RHA up to 0% nd then t 30% RHA, the to the CH to produce dditionl C-S-H gel which compressive strength of lended concrete ttins contriutes to improve microscopic property of cement equivlent strength to tht of OPC concrete [5]. The production of more C-S-H gel in concrete with specimens. The vlue of compressive strength RHA my improve the concrete properties due to the decreses thn tht of OPC concrete eyond 35% RHA rection mong RHA nd clcium hydroxide in hydrting mixture [34] Similr results - the compressive strength of cement [54]. However, incorportion of RHA s prtil concrete contining up to 30% RHA ws higher thn tht replcement of cement improves the compressive of control concrete t 7, 14, 8 nd 90 dys - were strength of concrete for the optimum replcement level oserved y Zhng nd Mlhotr [47]. Therefore, 30% (10% to 30%) of OPC y RHA. In ll of those reserches, replcement of RHA ppers to e the optiml limit for the replcement levels of RHA re considered s RHA lended concrete. On the other hnd, the 90 dys percentge y weight of the totl inder mteril. compressive strength of concrete mde with RHA up to The mortr strength s influenced y the RHA 40% ws higher thn the corresponding concrete mixtures replcement for cement is shown in Tle. Gnesn without RHA [9]. The excellent pozzolnic ctivity nd et l. [34] found tht mortr contining 0% of RHA greter compressive strength of RHA lended concrete showed greter compressive strength thn tht of OPC re due to the morphous silic nd the fine prticle size cement mortr s mentioned in this Tle. For ll content of RHA [34]. 1505

6 Tle 3: Compressive strength of RHA mixed concrete Compressive Strength (MP) t dys RHA:OPC W/B rtio References 0: [34] 05: : : : : : : : [35] 10: : : : [36] 0: (10FA: 10RHA): : : [39] 05: : : : : [41] 10: : : : [4] 10: : : [57] 0: : : : : [58] 1.5: : :

7 Tle 4: Split tensile strength (MP) t 8 dys Tensile Strengths (MP) t 8 dys s otined from references: [39] [41] [4] [55] [60] RHA:OPC Strength W/B rtio Strength W/B rtio Strength W/B rtio Strength W/B rtio Strength W/B rtio 00: : : c d,e ; : RHA pssing #00 sieve; RHA pssing #35 sieve; c, d, e- Averge prticle size of RHA is 31.3, 18.3 nd 11.5 µm respectively For the 10% RHA replcement, Zhng et l. [40] otined greter strength thn control OPC t ll ges. They oserved higher compressive strength nd reduced permeility in RHA lended concrete; this could e occurred, perhps, due to the reduced porosity, reduced clcium hydroxide content nd reduced width of the interfcil zone etween the pste nd the ggregte. The RHA concrete chieved higher compressive strength t 91 dys in comprison to tht of the concrete without RHA s investigted y Rodriguez et l. [46]. Isi et l. [58] investigted tht compressive strength of concrete Fig. : Compressive strength development for M nd U with RHA increses due to etter pozzolnic nd filler series t 10% level of cement replcement y RHA (physicl) effect. This conclusion ws lso greed y De in comprison to control smple t the first 90 Sensle [4] from his study. dys. M series: RHA-lended concrete with At 10% replcement of RHA with fine nd ultr fine verge prticle size of 95 µm. U series: ultr fine prticle, the greter compressive strength were found from RHA-lended concrete [35]. investigtion of Givi et l. [35] tht hs een shown in Figure. They concluded - the rpid consuming of A reserch work ws performed y Hee nd Fyydh C(OH) which is formed during hydrtion of Portlnd [60] to investigte the effects of concrete incorporting cement t erly ges - is the reson for these fvorle 0% RHA s prtil replcement of cement t three results of ultr fine RHA-lended concrete. As different prticle sizes. They found tht the tensile consequence, the hydrtion of cement is ccelerted nd strength of concrete increses systemticlly with lrger volumes of rection products re formed, they lso incresing RHA replcement. The results of tensile nd mentioned. In fct, sed on the literture, generlly RHA flexurl strength re shown in Tle 4. The utiliztion of lended cement exhiits similr or higher compressive RHA lso shows significnt improvement in flexurl strength s compred to OPC for prticulr level of RHA strength [4] nd split tensile strength [39]. The results of replcement (out 0-30%). It is concluded tht RHA cn splitting tensile strength nd less ir permeility re fford positive effect for erly compressive strength oserved y De Sensle [4], which cn e cused for chievement of concrete. On the other hnd, the residul RHA nd the filler effect of the smller prticles compressive strength of RHA (produced with controlled in the mixture. However, the corser RHA prticle mixture incinertion) lended concrete shows etter performnce shows smller increment in tensile nd flexurl strength s t the longer ge. reported y Hee nd Fyydh [60]. The greter flexurl strength nd the higher compressive strength ws Tensile Strength of RHA Concrete: Tensile strength of oserved y Zhng et l. [40] in the RHA lended concrete is essentil to evlute the lod t which the concrete for the finer RHA mixture due to the incresed concrete structure my crck; its knowledge is useful in pozzolnic rection nd the pcking ility of the RHA the design of pvement sls nd irfield runwy [59]. fine prticles. Splitting tensile strength of RHA lended 1507

8 form. As result of this chrcteristic, RHA is n extremely rective pozzolnic mteril nd it is suitle to use in lime-pozzoln mixes nd Portlnd cement s supplement. According to Dkroury et l. [5], the rectivity of RHA ssocited to lime depends on the following two fctors: (i) the non-crystlline silic content nd (ii) its specific surfce. RHA with fine prticle when used s cement replcement mteril cn ccelerte the erly hydrtion of triclcium silicte (C3S). The high specific surfce re of the RHA is the min cuse to produce this phenomenon [63]. They lso stted tht pozzolnic ctivity of RHA - produced y hydrochloric Fig. 3: Splitting tensile strength of RHA lended cid pretretment of rice husk - is enhnced s compre to concretes [34] tht of RHA without tretment (ordinry RHA). While the smll prticles of pozzolns re less rective thn Portlnd concretes ws investigted y Gnesn et l. [34]; these cements [65], they generte lrge numer of nucletion test results re presented in Figure 3. It is seen from this cites for the precipittion of the hydrtion products y Figure tht tensile strength of RHA lended concrete dispersing in cement pstes. grdully increses up to 0% replcement of RHA. Accordingly, more homogenous nd denser pste is produced y this mechnism for the distriution of the Pozzolnic Activity of RHA: According to the definition finer pores s well s due to the pozzolnic rections of The Americn Society of Testing nd Mterils mong the morphous silic of the minerl ddition nd (ASTM), pozzoln is siliceous or lumino-siliceous the CH [58]. There is no pozzolns (mong slg, silic mteril tht itself hs little or no cementitious property fume, fly sh) except RHA, tht hs the ility to ut in finely divided form nd in the presence of moisture contriute strength of OPC concrete t the erly ge. it will chemiclly rect with lkli nd lkline erth Mlhotr [66] concluded tht the strength development of hydroxides t ordinry tempertures to form RHA concrete is similr to fly sh/slg concrete ut with compounds tht possess cementitious properties [61]. higher pozzolnic ctivity it helps the pozzolnic The improvement of rte of pozzolnic rection nd rections occur t erly ges rther thn lter s is the hrdening of pozzoln-lime mortrs cn e done y cse with other replcement cementing mterils. From restoring to different mens: grinding firing pozzolns, reserch work, Meht [67] reported tht the finer prticles compcting mixes nd dding some chemicls [6]. of RHA speed up the rections nd form smller CH The most importnt contriution of RHA is the pozzolnic crystls. Berry et l. [68] reveled tht high volume of ctivity tht cn e formed due to morphous phse RHA not completely rected fill up the voids nd enhnce sustnce. Clcium hydroxide C(OH) nd clcium density of the pste. The pozzolnic rection cn e silicte hydrtes C-S-H re the mjor hydrtion nd stisfctorily descried y the Jnder diffusion eqution rection products for RHA pste. The incorportion of tht is sed on Fick's prolic lw of diffusion [69]. RHA in concrete reduces its porosity nd the mount of The Jnder eqution for three- dimensionl diffusion in C(OH) in the interfcil zone; the width of interfcil 1/3 sphere cn e stted s: F (G) = [1- (1 G) ] = (kt/r ) zone etween ggregte nd the cement pste is lso 1/3 = Kt. Where F (G) represents the eqution [1- (1 G) ] ; reduced s compred to OPC pste [40]. Approximtely G = frction of the sphere tht hs rected; r = initil 85% to 95% y weight of morphous silic cn e rdius of the strting sphere; k = prolic rte constnt originted y the production of rice husk sh [3]. nd K= constnt proportionl to k, which indictes the Yu et l. [54] studied the rection etween RHA nd rection. C(OH) solution nd they suggested tht in the presence of wter, kind of fine C-S-H gel is formed fter their Advntges of Supplementry Use of RHA: RHA hs rection. This result is in greement with the findings of een used s good pozzolnic nd supplementry Feng et l. [63]. However, Lin et l. [64] reported tht mteril in concrete s investigted in different litertures. morphous silic found in some pozzolnic mterils Besides tht, it prticiptes to produce denser nd rects with lime more egerly thn those of crystlline durle concrete with prticulr level (out 0-30%) of 1508

9 replcement. Bsed on the discussions presented in this C Among the pozzolns (slg, silic fume, fly sh) RHA pper, vrious dvntges of RHA - improved strength, hs the ility to contriute to gin erly strength reduced mteril costs due to cement sving, durility [73]. properties, environmentl enefits to the disposl of RHA wste - hve een oserved to use in cement or concrete. Disdvntges of Using RHA: Effective consumption of The incorportion of RHA in concrete hs the following RHA in cement or concrete hs gret importnce essentil enefits: regrding strength, durility nd cost effectiveness of concrete up to certin replcement percent. Hving the C Improves compressive strength [6, 35, 55], more enefits using RHA in cement or concrete, it shows flexurl strengths [, 40, 41] nd split tensile few disdvntges tht re mentioned elow: strength [39, 4, 60]. C RHA mixed concrete shows etter ond strength s C Suitle incinertor/furnce s well s grinding compred to OPC concrete [39, 55]. method is required for urning nd grinding rice husk C Permeility of concrete decreses [55, 40, 46], in order to otin good qulity sh. chloride diffusion nd chloride permetion reduces C Strength of concrete is reduced for lrger (eyond [34, 53]. 30%) replcement [34, 36]. C RHA mkes role to incresed resistnce to chemicl C There is little trnsporttion prolem. ttck [3]. C Unurnt RHA is not suitle for concrete C Shows etter durility of concrete []. production. C Improves resistnce to sulfte ttck [, 3, 39]. C Reduces the mount of cement for mking concrete Concluding Remrks: There re huge mounts of RHA up to 0% y weight [35]. produced s y-product from the rice processing mills, C Improves the corrosion resistnce nd strength of minly in developing countries, which re disposed to concrete s compred to tht of OPC concrete environment without ny return price. Therefter, disposl [36, 55]. cost is incresed in order to trnsport this sh; lso C Reduces effects of lkli-silic rectivity [37]. lrge lnd re ecomes useless nd the fertility of lnd is C Reduces shrinkge due to prticle pcking, mking reduced. So the prolem cn e solved or minimized y concrete denser [60]. properly utilizing the RHA through the production of C Enhnces workility of concrete [, 60]. cement or concrete s well s production of silic. C Reduces het grow through the wlls of uildings Becuse, RHA contins lrge mount of silic nd lso [5]. exhiits excellent pozzolnic property. In fct, C Reduces mount of super plsticizer [38]. incorportion of RHA either in cement or in concrete not C Decreses ir permeility due to the filler nd only fulfills the demnd of cement ut lso mkes role in pozzolnic effect [4]. production of durle concrete. The strength C Binry mixture of RHA shows etter performnces development of concrete produced with prticulr level thn fly sh [58]. of RHA replcement is the sme or higher s compred to C Electricl resistivity [70] nd ultrsonic pulse velocity OPC concrete. For out 0-30% replcement of RHA, no of concrete increse [6]. significnt reduction in strength of concrete is oserved. C Reduces the plsticity of soil [51]. Furthermore, vlule cement nd energy sving C Compressive strength is directly relted to the considertion could e performed y proper utiliztion of concrete porosity [49], RHA reduces porosity of RHA in the production of cement or concrete tht cn e concrete [36, 40, 71]. eneficil for the present demnd of concrete industry. C Increses compressive strength nd decreses RHA sed snd-cement lock cn significntly lechility [5]. reduce room temperture; hence ir conditioner opertion C Reduces mteril cost nd emission of CO due to time is reduced, resulting electricl energy svings [5]. less cement utiliztion [55]. The present essentil issues - disposl solution, C Improves consistency of OPC- RHA lended pste environmentl mngement s well s sustinle with incresing RHA percent [7]. concrete production - could e ttined y effective C RHA could e used s n lterntive source for high consumption of RHA in cement or concrete. The ddition surfce re silic [3]. of RHA to the cement or concrete is ecologicl, economic 1509

10 nd energy sving step for uilding clen nd sfe 7. Chusilp, N., C. Jturpitkkul nd K. Kittikomol, gloe for the future genertion. Furthermore, most of the 009. Effects of LOI of Ground Bgsse Ash on the cited reserch rticle re reported sed on the study of Compressive Strength nd Sulfte Resistnce of inry lend (RHA nd OPC) s supplement (mximum Mortrs. Construction nd Building Mterils, 40%) of OPC; thus, ternry lend of RHA with slg, fly 3(1): sh, plm oil fuel sh or ny other nturl pozzolns cn 8. Bsri, H.B., M.A. Mnnn nd M.F.M. Zin, further e investigted; esides, more thn 50% nd even Concrete Using Wste Oil Plm Shells s Aggregte. 100% replcement of these wste mterils y OPC long Cement nd Concrete Reserch, 9(4): with mechnicl or chemicl ctivtion process cn lso 9. St, V., C. Jturpitkkul nd R. Chiynunt, 010. e studied. Compressive Strength nd Het Evolution of ACKNOWLEDGEMENTS Concretes Contining Plm Oil Fuel Ash. Journl of Mterils in Civil Engineering, (10): Initilly, the uthors wish to thnk to Almighty Allh 10. Tngchirpt, W., C. Jturpitkkul nd for strting this reserch. The uthors would like to P. Chindprsirt, 009. Use of Plm Oil Fuel Ash s express specil thnks to Universiti Kengsn Supplementry Cementitious Mteril For Producing Mlysi; Ministry of Science, Technology nd High-Strength Concrete. Construction nd Building Innovtion; Fundmentl Reserch Grnt Scheme (FRGS); Mterils, 3(7): nd Deprtment of Civil nd Structurl Engineering for 11. Ty, Journlh. nd K.Y. Show, Use of Ash providing the funds of the reserch. The first uthor Derived From Oil-Plm Wste Incinertion s expresses honest grtefulness to Dhk University of Cement Replcement Mteril. Resources, Engineering nd Technology (DUET), Gzipur, Conservtion nd Recycling, 13: Bngldesh for providing him leve for the reserch. 1. Aziz, M.A.E., S.A.E. Aleem, M. Heikl nd H.E. Didmony, 005. Hydrtion nd Durility of REFERENCES Sulphte-Resisting nd Slg Cement Blends in Cron s Lke Wter. Cement nd Concrete Reserch, 1. Bui, D.D., J. Hu nd P. Stroeven, 005. Prticle Size 35(8): Effect on the Strength of Rice Husk Ash Blended 13. Agrwl, S.K. nd G. Deepli, 006. Utiliztion of Gp-Grded Portlnd Cement Concrete. Cement nd Industril Wstes nd Unprocessed Micro-Fillers for Concrete Composites, 7(3): Mking Cost Effective Mortrs. Construction nd. Chtveer, B. nd P. Lertwttnruk, 009. Evlution Building Mterils, 0(10): of Sulfte Resistnce of Cement Mortrs Contining 14. Brnett, S. Journl, M.N. Soutsos, S.G. Millrd nd Blck Rice Husk Ash. Journl of Environtl Journlh Bungey, 006. Strength Development of Mngement, 90(3): Mortrs Contining Ground Grnulted Blst Furnce 3. Chindprsirt, P., P. Knchnd, Slg: Effect of Curing Temperture nd Determintion A. Sthonsowphk nd H.T. Co, 007. Sulfte of Apprent Activtion Energies. Cement nd Resistnce of Blended Cements Contining Fly Ash Concrete Reserch, 36(3): nd Rice Husk Ash. Construction nd Building 15. Binici, H., T. Huseyin nd M.K. Mehmet, 007. Mterils, 1(6): The Effect of Fineness on the Properties of the 4. Chindprsirt, P., S. Rukzon nd V. Sirivivtnnon, Blended Cements Incorporting Ground 008. Resistnce to Chloride Penetrtion of Blended Grnulted Blst Furnce Slg nd Ground Portlnd Cement Mortr Contining Plm Oil Fuel Bsltic Pumice. Construction nd Building Ash, Rice Hush Ash nd Fly Ash. Construction nd Mterils, 1(5): Building Mterils, (5): Bouzou, N., A. Bilodeu, V. Sivsundrm, 5. Dkroury, A.E. nd M.S. Gsser, 008. Rice Husk Ash B. Fournier nd D.M. Golden, 004. Development of (RHA) s Cement Admixture for Immoiliztion of Ternry Blends High Performnce Cement. ACI Liquid Rdioctive Wste t Different Tempertures. Mterils Journls, 101(03): Journl of Nucler Mterils, 381(3): Bouzou N.B. Fournier, V.M. Mlhotr nd 6. Sfiuddin, M., J. West nd K.A. Soudki, 010. D.M. Golden, 00. Mechnicl Properties nd Hrdened Properties of Self-Consolidting High Durility of Concrete Mde With High Volume Fly Performnce Concrete Including Rice Husk Ash. Ash Blended Cement Produced in Cement Plnt. Cement Concrete nd Composites, 3(9): ACI Mterils Journl, 99(57):

11 18. Bouzou, N., M.H. Zhng nd V.M. Mlhotr, 9. Bhnumthids, N. nd P.K. Meht, 004. Concrete 001. Mechnicl Properties nd Durility of Concrete Mde With High-Volume Fly Ash Blended Cements Using Corse Fly Ash. Cement nd Concrete Reserch, 31(3): Cheerrot, R. nd C. Jturpitkkul, 004. A study of Disposed Fly Ash From Lndfill To Replce Portlnd Mixtures Mde With Ternry Blended Cements Contining Fly Ash nd Rice Husk Ash. In the Proceedings of the 004 Seventh CANMET Interntionl Conference, pp: Anwr, M., T. Miygw nd M. Gweesh, 000. Using Rice Husk Ash s Cement Replcement Cement. Wste Mngement, 4(7): Mteril in Concrete. Wste Mngement, 0. Kittikomol, K., C. Jturpitkkul, S. Songpiriykij nd S. Chututim, 001. A study of Ground Corse Fly Ashes with Different Finenesses from Vrious Sources s Pozzolnic Mterils. Cement nd Concrete Composites, 3(4-5): (1): Bilodeu, A. nd V.M. Molhotr, 000. High Volume Fly Ash System: Concrete Solution for Sustinle Development. ACI Mterils Journl, 97(1): Chindprsirt, P., C. Jturpitkkul nd 3. Meht, P.K., Concrete Technology for U. Rttnsk, 009. Influence of Fineness of Rice Sustinle Development. Concrete Interntionl, Husk Ash nd Additives on the Properties of 1(11): Lightweight Aggregte. Fuel, 88(1): Nehdi, M., 001. Ternry nd Qurternry Cements. Coutinho, J., 003. The Comined Benefits of CPF for Sustinle Development. Concrete Interntionl, nd RHA in Improving the Durility of Concrete 3(4): Structures. Cement nd Concrete Composites, 34. Gnesn, K., K. Rjgopl nd K. Thngvel, (1): Rice Husk Ash Blended Cement: Assessment of 3. Dell, V.P., I. Kuhn nd D. Hotz, 00. Rice Husk Optiml Level of Replcement for Strength nd Ash s n Alternte Source for Active Silic Permeility Properties of Concrete. Construction Production. Mterils Letter, 57(4): nd Building Mterils, (8): Jturpitkkul, C., K. Kittikomol, W. Tngchirpt 35. Givi, N.A., S.A. Rshid, F.N.A. Aziz nd nd T. Seting, 007. Evlution of the Sulfte S.M.A. Mohd, 010. Assessment of the Effects of Resistnce of Concrete Contining Plm Oil Fuel Rice Husk Ash Prticle Size on Strength, Wter Ash. Construction nd Building Mterils, Permeility nd Workility of Binry Blended 1(7): Concrete. Construction nd Building Mterils, 5. Lertstitthnkorn, C., S. Atthjriykul nd 4(11): S. Soponronnrit, 009. Techno-economicl 36. Chindprsirt, P. nd S. Rukzon, 008. Strength, Evlution of Rice Husk Ash (RHA) Bsed Porosity nd Corrosion Resistnce of Ternry Blend Snd-Cement Block for Reducing Solr Conduction Portlnd Cement, Rice Husk Ash nd Fly Ash Het Gin to Building. Construction nd Building Mterils, 3(1): Mortr. Construction nd Building Mterils, 6. Rukzon, S. nd P. Chindprsirt, 009. Strength nd (8): Chloride Resistnce of Blended Portlnd Cement 37. Nicole, P.H., P.J.M. Monteiro nd H. Crsek, Mortr Contining Plm Oil Fuel Ash nd Fly Ash Effect of Silic Fume nd Rice Husk Ash Interntionl Journl of Minerls, Metllurgy nd on Alkli-Silic Rection. Mterils Journl, Mterils, 16(4): (4): Rukzon, S. nd P. Chindprsirt, 009. An 38. St, V., C. Jturpitkkul nd K. Kittikomol, 007. Experimentl Investigtion of the Crontion of Influence of Pozzoln from Vrious By-product Blended Portlnd Cement Plm Oil Fuel Ash Mortr in n Indoor Environment. Indoor nd Built Environment, 18(4): Mterils on Mechnicl Properties of High-Strength Concrete. Construction nd Building Mterils, 1(7): Tngchirpt W.T. Seting, C. Jturpitkkul, 39. Skr, K., 006. Effects of Silic Fume nd Rice K. Kittikomol nd A. Siripnichgorn, 007. Use of Wste Ash from Plm Oil Industry in Concrete. Wste Mngement, 7(1): Husk Ash on the Properties of Hevy Weight Concrete. Journl of Mterils in Civil Engineering, 18(3):

12 40. Zhng, M.H., R. Lstr nd V.M. Mlhotr, Bsh, E.A., R. Hshim, H.B. Mhmud nd Rice Husk Ash Pste nd Concrete: Some Aspects of Hydrtion nd The Microstructure of the Interfcil Zone Between the Aggregte nd Pste. Cement nd A.S. Muntohr, 005. Stiliztion of Residul Soil With Rice Husk Ash nd Cement. Construction nd Building Mterils, 19(6): Concrete Reserch, 6(6): Sls, A., S. Delvsto, R.M. Gutierrez nd 41. Ismil, M.S. nd A.M. Wliuddin, Effect of Rice D. Lnge, 009. Comprison of Two Processes for Husk Ash on High Strength Concrete. Construction Treting Rice Husk Ash for Use in High nd Building Mterils, 10(7): Performnce Concrete. Cement nd Concrete 4. De Sensle, G.R., 006. Strength development of Reserch, 39(9): Concrete with Rice-Husk Ash. Cement nd Concrete 53. Nehdi, M., J. Duquette nd A. El Dmtty, 003. Composites, 8(): Performnce of Rice Husk Ash Produced Using 43. Smith, R.G. nd G.A. Kmwnj, The Use of New Technology s Minerl Admixture in Rice Husk For Mking A Cementitious Mteril, Concrete. Cement nd Concrete Reserch, Proceedings of Joint Symposium on the Use of 33(8): Vegetle Plnts nd their Fiers s Building 54. Yu, Q., K. Swym, S. Sugit, M. Shoy nd Mteril, Bghdd. In: N.A. Givi, S.A. Rshid, Y. Isojim, The Rection Between Rice Husk F.N.A. Aziz, S.M.A. Mohd, 010. Contriution of Rice Husk Ash to the Properties of Mortr nd Ash nd C(OH) Solution nd the Nture of its Concrete: A Review. Journl of Americn Sciences, Product. Cement nd Concrete Reserch, 9(1): (3): Srswthy, V. nd H. Song, 007. Corrosion 44. Siddique, F., 008. Wste Mterils nd By-products Performnce of Rice Husk Ash Blended in Concrete. Springer Press. In: Givi, N.A., Concrete. Construction nd Building Mterils, S.A. Rshid, F.N.A. Aziz nd S.M.A. Mohd, 010. Contriution of Rice Husk Ash to the Properties of Mortr nd Concrete: A Review. Journl of Americn Sciences, 6(3): Zin, M.F.M., M.N. Islm, F. Mhmud nd M. Jmil, 010. Production of Rice Husk Ash for Use in Concrete s Supplementry Cementitious Mteril. Construction nd Building Mterils, 5(): Rodrigues, C.S., K. Ghvmi nd P. Stroeven, (8): Mhmud, H.B., N.B.A.A. Hmid nd B.S. Chi, High Strength Rice Husk Ash- Preliminry rd Investigtion. In the Proceedings of the Asi Pcific Conferences on Structurl Engineering nd Construction, pp: Gstldini, A.L.G., G.C. Isi, N.S. Gomes nd J.E.K. Sper, 007. Chloride Penetrtion nd Crontion in Concrete with Rice Husk Ash nd Porosity nd Wter Permeility of Rice Husk Chemicl Activtors. Cement nd Concrete Ash-Blended Cement Composites Reinforced Composites, 9(3): with Bmoo Pulp. Journl of Mterils Sciences, 58. Isi, G.C., A.L.G. Gstldini nd R. Mores, (1): Physicl nd Pozzolnic Action of Minerl Additions 47. Zhng, M.H. nd V.M. Mlhotr, Highperformnce Concrete Incorporting Rice Husk Ash on the Mechnicl Strength of High-Performnce Concrete. Cement nd Concrete Composites, s Supplementry Cementing Mteril. ACI 5(1): Mterils Journl, 93(6): Gmhir, M.L., Concrete Technology, Tt 48. Nir, D.G., K.S. Jgdish nd F. Alex, 006. Rective McGrw-Hill Pulishing Compny, New Delhi, Pozzolns from Rice Husk Ash: An Alterntive to pp: Cement for Rurl Housing. Cement nd Concrete 60. Hee, G.A. nd M.M. Fyydh, 009. Rice Husk Reserch, 36(6): Ash Concrete: the Effect of RHA Averge Prticle 49. Neville, A.M., Properties of Concrete, Longmn, Singpore. Size on Mechnicl Properties nd Drying 50. Meht, P.K., Rice Husk Ash- Unique Shrinkge. Austrlin Journl Bsic nd Applied Supplementry Cementing Mteril. In: Nehdi, M., Sciences, 3(3): J. Duquette nd A. El Dmtty, 003. Performnce of 61. ASTM, Americn Society for Testing nd Rice Husk Ash Produced Using New Technology s Minerl Admixture in Concrete. Cement nd Concrete Reserch, 33(8): Mterils Stndrd Specifiction for Fly Ash nd Other Pozzolns for Use with Lime, ASTM C593-95, West Conshohocken, PA. 151

13 6. Msszz, F., 00. Properties nd Applictions of 69. Crer, J. nd M.F. Rojs, 001. Mechnism of Nturl Pozzolns. In: Bensted, J., P. Brnes, 00. Hydrtion of the Metkolin-Lime-Wter System. Structure nd Performnce of Cement. Second Cement nd Concrete Reserch, 31(): Edition, pp: Gstldini, A.L.G., G.C. Isi, T.F. Hoppe, F. Missu 63. Feng, Q., H. Ymmichi, M. Shoy nd S. Sugit, nd A.P. Sciloto, 009. Influence of the Use of Rice 004. Study on the Pozzolnic Properties of Rice Husk Ash on The Electricl Resistivity of Husk Ash y Hydrochloric Acid Pretretment. Concrete: A Technicl nd Economic Fesiility Cement nd Concrete Reserch, 34(3): Study. Construction nd Building Mterils, 64. Lin, R.B., S.M. Shih nd C.F. Liu, 003. (11): Chrcteristics nd Reltivities of C(OH) /Silic 71. Chindprsirt, P. nd S. Rukzon, 009. Pore Structure Fume Sorents for Lowtemperture Flue Gs Chnges of Blended Cement Pstes Contining Fly Desulfuriztion. Chemicl Engineering Sciences, Ash, Rice Husk Ash nd Plm Oil Fuel Ash Cused 58(16): y Crontion. Journl Mterils Civil Engineering, 65. Meht, P.K. nd P.C. Aitcin, Principles 1(11): Underlying Production of High-Performnce 7. Singh, N.B., V.D. Singh, R. Srit nd C. Shivni, Concrete. Journl of Cement Concrete nd 00. Effect of Lignosulfonte, Clcium Chloride nd Aggregtes, 1(): Their Mixture on the Hydrtion of RHA-lended 66. Mlhotr, V.M., Fly Ash, Slg, Silic Fume nd Portlnd Cement. Cement nd Concrete Reserch, Rice Husk Ash in Concrete: A Review. Concrete 3(3): Interntionl, 15(4): Meht, P.K. nd K.J. Follird, Rice Husk Ash- 67. Meht, P.K., Studies on the Mechnisms y A Unique Supplementry Cementing Mteril: Which Condensed Silic Fume Improves the Durility Aspects. ACI Mterils Journl, 154(SP): Properties of Concrete: Durility Aspect. In In: Singh, N.B., V.D. Singh, R. Srit, Proceedings of Interntionl Workshop on C. Shivni, 00. Effect of Lignosulfonte, Clcium Condensed Silic Fume in Concrete, Ottw, pp: Chloride nd Their Mixture on the Hydrtion of 68. Berry, E., R.T. Hemmings, M. Zhng, B.J. Cornelius RHA-lended Portlnd Cement. Cement nd Concrete nd D.M. Golden, Hydrtion in High-Volume Reserch, 3(3): Fly Ash Concrete Binders. ACI Mterils Journl, 91(4):