The Impact Of Using Polymer Impregnated Porous Concrete In Structural .
International Journal of Current Engineering and TechnologyE-ISSN 2277 – 4106, P-ISSN 2347 – 5161Available at http://inpressco.com/category/ijcet 2017 INPRESSCO , All Rights ReservedResearch ArticleThe impact of using Polymer Impregnated Porous Concrete inStructural Engineering ApplicationsSameh Yehia* and Mona M. FawzyHigher Institute of Engineering, El-Shorouk Academy, Cairo, EgyptAccepted 18 March 2017, Available online 20 March 2017, Vol.7, No.2 (April 2017)AbstractThis paper presents a focused study on properties of porous concrete to widen its application to structuralengineering. Mechanical properties like compressive strength, indirect tensile strength, flexural strength and physicalproperties like density, permeability and porosity are studied. To determine those parameters, twenty-seven cubes,cylinders and prisms were tested. Also, three polymer impregnated porous concrete slabs were tested under purebending moment to study the efficiency of selected resin to integrate particle of concrete to achieve a new generationin using porous concrete in structural engineering. Three different cement content specimens of porous concrete wereconsidered, studied cement contents are 200 kg/m 3, 300 kg/m3 and 400 kg/m3. The results show that, increasing thecement content can increase the compressive strength, indirect tensile strength and flexural strength. Density ofporous concrete is less than conventional concrete by 21% but permeability factor recorded higher value comparedto conventional concrete by sixteen times. Increasing the cement content has no significant effect on either ultimateload or maximum deflection of polymer impregnated porous concrete slabs but the results recorded an achievementto use this concrete in structural engineering applications and give an easy way to cast special concrete like polymerconcrete without special tools.Keywords: Porous Polymer Concrete, Mix Design, Mechanical and Physical Properties, Structural Application ofPorous Concrete, Unreinforced Slab.1. Introduction1 Porousconcrete is a special type of advanced concrete,it is a high porosity concrete used for outdoor flatwork(public works) that allows water to pass through it. Itis a low water/cement ratio, low slump mix consistingof cement, narrowly graded coarse aggregate, little orno fine aggregate, water and admixtures. It is heldtogether by cementitious paste at the coarse aggregatecontact points since there is limited paste and fineaggregate to fill the voids between the coarseaggregate. The amount of water used in a mix is highlycritical. Too much water and the mix will segregate; toolittle water will lead to balling in the mixer and slowunloading times. The perfect and ideal amount of waterwill impart a wet metallic appearance or sheen.Squeezing and releasing a handful of the mix shouldresult in a mix that neither crumbles (too dry) nor loseits structure as paste flows away from the aggregates(too wet). Too little water can also hinder curing of theconcrete and could lead to premature raveling of thesurface. The actual mix proportions for porousconcrete varies depending on the application,mechanical properties required and materials used.Admixtures are often used to control the normal rapidsetting of porous concrete. They are used to increaseworkability, allow concrete to easily move out of themixer, and control the setting time so the mix may beplaced correctly. The following Table 1 provides somematerial ranges as well as more typical use to help mixdesigner. Nowadays, special concrete is highlyrecommended and can help us to cast new buildingswith new enhanced features, from that the aim ofresearch came.Table 1: Mix Proportions for Porous ConcreteProportionof MixesCementitiousMaterialCoarse lity*Corresponding author Sameh Yehia and Mona M. Fawzy areworking as Assistant ProfessorsVoid ContentProportionRange(W. R.Grace&Co.Conn, 2006)270 to 415kg/m31190 to1600 kg/m3TypicalProportions(W. R.Grace&Co.Conn, 2006)325 to 400kg/m31400 to 1550kg/m3224 to 388kg/m31431 to1670 kg/m30.20 to 0.450.27 to 0.300.27 to 0.38200 to 400ml/100kg100 to 900L/min/m2300ml/100kg500L/min/m2200 to 400ml/100kg200L/min/m215% to 35%20% to 30%13 to 30%ProportionRange(Axim,2006)634 International Journal of Current Engineering and Technology, Vol.7, No.2 (April 2017)
The impact of using Polymer Impregnated Porous Concrete in Structural Engineering This paper covers some of the main properties anduses of traditional porous concrete and its ecofriendlyuse in structural applications. This concrete may bevery beneficial if it is utilized to its full extent instructural applications. The most important parameterstudied in this paper is changing the percentage ofcement content. This parameter plays the leading rolein the performance of any concrete mix. Compressivestrength, indirect tensile strength and flexural strengthare measured after seven days, fourteen and twentyeight days in addition to density. Permeability for castslab specimens were calculated by Darcy's Law andporosity experimentally calculated then slabsintegrated with resin to study the flexural behavior andits resistance in structural applications. Finally,comparisons were took place to study the relationshipbetween properties and different factors.Table 2: Concrete Mix Design ProportionsWater/CementRatio2. Objective1500kg/m3, respectively. (Viscocrete Admixture)was used as admixture to enhance fresh concreteperformance; the added dose is equal to 300 ml/100kgcement. Table (2) shows the proportions of concretemixes.Testing of porous concrete specimens were carriedout after curing for seven days, fourteen days andtwenty-eight days. Curing were took place aftertwenty-four hours with spraying mode and specimenswere covered with burlap. Cubes were tested forcompressive strength, cylinders for indirect tensilestrength and finally prisms for flexural strength. Testswere carried out according to (BS EN 5328).CoarseAggregate(kg/m3)As the void content increases, the water drainage ratethrough the concrete also increases and this option canbe use later to increase resin content in polymerimpregnated concrete. If more strength is needed, asmall amount of fine aggregate could be added to themix, but this will reduce the void content and itspermeability. Typical compressive strength rangesbetween 35 to 280 kg/cm2, and mostly compressivestrength 170 kg/cm2 is common. Slump is usually lessthan 20 mm. Chemical admixtures are used to affectthe water/cementitious ratio, influence workabilityand setting times and enhance mechanical propertiesand durability. Porous concrete has an interconnectedpore structure that freely allows the passage of waterto flow through also, it's not easy to manufacturepolymer concrete because it needs special labors andmachines. Pore porous concrete structure option willbe helping in installing resin to widen the applicationof porous concrete from public works (pavements) tostructural applications (reliable unreinforced concreteslab).MixesCodeSameh Yehia et alMix (A)Mix (B)Mix 2003.2. Manufacturing Procedures of SpecimensThin layer of oil was applied to cover slab woodenmold to easily fabricate porous concrete slab. Themixing process were took place as usual by usingconcrete mixer. Fresh concrete was mixed with waterplus admixtures then fresh concrete was poured inwooden molds by batching mode without compaction.Finally, specimens were leveled from top to get thesame level of concrete surface. As shown in Figure (1)the specimens were casted and ready for curing byspraying mode.3. Experimental Work Program3.1 IntroductionTwo phases were took place in this research. FirstPhase, three slabs were cast with 10 cm thickness, 50cm length and width, in additional to nine cubes15x15x15 cm, cylinders 15x30 cm and prisms10x10x50 cm for each trial mix. Second Phase, theresearch focused on studying the structural behavior ofpolymer impregnated porous concrete. Accordingly,resin was used to fill the voids partially in porousconcrete to increase capability of sustained load, whichwill help to reliability use of this concrete in structuralapplications.3.1.2 Details of Concrete SpecimensThe specimens of porous concrete were mixed withthree different cement content, 200, 300, and400kg/m3. The water cement ratio and coarseaggregate in all concrete mixes were 0.30 andFigure 1: Final Specimens3.3. Testing of Phase One SpecimenCubes were tested under axial compression, cylinderswere tested under indirect tension and finally prismswere tested under pure bending moment. Testingmachine of capacity 50 ton was used. Testing processwas carried out in accordance with (BS EN12390:2009).635 International Journal of Current Engineering and Technology, Vol.7, No.2 (April 2017)
Sameh Yehia et alThe impact of using Polymer Impregnated Porous Concrete in Structural Engineering Applications3.3.1 The permeability test for cast concrete slabspecimen (without resin)Permeability can be defined as the property thatgoverns the rate of flow of a fluid into a porous solid.The concrete slabs were tested after twenty-eight daysto obtain the following factors which are included inthe shown equation (1) (Darcy’s law) (Toy, 1924) tocalculate permeability factor of tested slab understeady state flow. The coefficient of permeability K isdetermined as:Dq/dt K (Δ H A)/(Lν)Figure 3: Pouring Polyester for Slab Specimen(1)WhereDq/dt: is the rate of fluid flow.Δ H: the pressure gradient.A: the surface area.L: the thickness of the solid.ν: the viscosity of the fluid.It is worth to be mentioned that, cylindrical tube withknown diameter (20cm) was used to fill it with waterand control effected area (A) and this process arenormally carried out for any test of permeability.Figure 4: Final Shape of Polymer Slab Specimen3.4. Preparing Polymer Impregnated Concrete SlabSpecimensIn this phase, cement mortar was used to cover thespecimen from four sides and bottom of slab to act as aclosed box; which helped to filling slab specimens withpartially resin (J-FIX Polyester Resin). The porosity(voids %) of porous concrete is measured by filling theslab specimens with fully water and water volume wasobserved to obtain porosity and to ensure a closed boxaction before pouring resin. The detected value isapproximately 30% of total volume of specimen. Thevolume of resin was stacked in all slab specimens andcovered by 75% of total volume of voids percentage.Figures (2) and (3) show the process of mortaring fromoutside and filling slab specimens with resin. Pouringprocess was carried out regularly with different layersto ensure great integrity between concrete ingredients.Finally, specimens were tested under two static loadsfor flexure behavior. Figure (4) represents the finalslab specimen before testing. Also, Figure (5) showsscheme to present ingredients of concrete.Figure 2: Slab Specimen MortaringFigure 5: Porous Concrete Scheme3.5. Testing of Polymer Impregnated Concrete SlabSpecimensThree polymer slab specimens were tested under effectof two static loads causing pure bending moment at themiddle of specimens as shown in Figure (6). Each slabhad different cement content. S-1 had cement contentequal to 200 Kg/m2, S-2 had cement content equal to300 Kg/m2 and S-3 had cement content equal to 400Kg/m2. Deflection was measured by LVDT device whichwas fixed at the middle of clear span. Cracks wereobserved and recorded to identify the failure type foreach specimen.Figure 6: Test Setup for Specimens636 International Journal of Current Engineering and Technology, Vol.7, No.2 (April 2017)
The impact of using Polymer Impregnated Porous Concrete in Structural Engineering ApplicationsTable 3: Density of Tested Concrete SpecimensConcrete TypeDensity (t/m3)Permeability(cm/sec)TraditionalConcrete2.256 x 10-11as ReferencePorous Concrete*1.789.6 x 10-10* Calculated as a average of tested smsFlexuralStrengthAs anAverageof 3 RepeatsCompressiveStrengthTesting TimeTest TypeCement Content 200 kg/m3Mix (A)Cement Content 300 kg/m3Mix (B)Cement Content 400 kg/m3Mix (C)Cubes200 kg/m37 Days14 Days28 Days7 Days14 Days28 Days7 Days14 Days28 Days7 Days14 Days28 Days7 Days14 Days28 Days7 Days14 Days28 Days7 Days14 Days28 Days7 Days14 Days28 Days7 Days14 Days28 Days37 kg/cm246 kg/cm259 kg/cm22 kg/cm23 kg/cm24 kg/cm23 kg/cm24 kg/cm25 kg/cm273 kg/cm297 kg/cm2120 kg/cm26 kg/cm28 kg/cm210 kg/cm27 kg/cm29 kg/cm212 kg/cm2140 kg/cm2165 kg/cm2205 kg/cm212 kg/cm215 kg/cm218 kg/cm213 kg/cm216 kg/cm221 kg/cm2300 kg/m3400 kg/m3250Load (ton)200150100500051015202530DaysFigure 7: Relationship between Compressive Strengthand Concrete Age using Different Cement Content200 kg/m3Load (ton)Test results are summarized in Tables (3) and (4). It isclear from Table (3) that the density of traditionalconcrete is higher than porous concrete by 26% also,the permeability of porous concrete is higher thantraditional concrete by about sixteen times. Thepermeability and void percentage values arecompatible with equation of A Contribution from ACICommittee 236 (Bentz & Sumanasooriya, 2010).Table (4), shows the results for specimens (cubes,cylinders and prisms) after seven, fourteen and twentyeight days with different cement contents. Cubes,cylinders and prisms were tested to get compressivestrength, indirect tensile strength and flexure strength,respectively. Mix (B) and (C) give compressivestrength, indirect tensile strength and flexural strengthmore than Mix (A) by approximately 198% and 378%for compressive strength, 266% and 500% for indirecttensile strength, 233% and 416% for flexural strength,respectively so that, the results of the tests show thatincreasing the cement content enhances the propertiesof the porous concrete. The increasing in cementcontent by 50kg/m3 can enhance the properties ofporous concrete by approximately 288%, 383%, 324%for compressive strength, indirect tensile strength andflexural strength, respectively. It's observed thatindirect tensile strength and flexural strength areranged by (6% to 9%) and (8% to 10%) as apercentage of compressive strength value. Therecorded value for indirect tensile strength liketraditional concrete on the other hand the valuerelated to flexural strength is very low percentagecompared to traditional concrete (Yehia, 2015) thisdue to missing of fine aggregate (sand) which is fill thevoids between coarse aggregate and give concreteingredients more integrity.Figure (7) shows the effect of increasing the cementcontent on the compressive strength at differentconcrete age also figure (8) presents the relationshipbetween cement content and indirect tensile strengthat different concrete ages. Finally, Figure (9) showsdifferent flexural strengths that correspond to variouscement contents at different concrete age. All thosefigures confirm the above analysis and gives clearindication about different relationships of mechanicalproperties of tested specimens.Table 4: Experimental Results of Tested ConcreteSpecimensTypeof Mix4. Results and DiscussionsSpecimenSameh Yehia et al300 kg/m3400 kg/m320181614121086420051015202530DaysFigure 8: Relationship between Indirect TensileStrength and Concrete Age using Different CementContent637 International Journal of Current Engineering and Technology, Vol.7, No.2 (April 2017)
Sameh Yehia et alThe impact of using Polymer Impregnated Porous Concrete in Structural Engineering Applications200 kg/m3300 kg/m3indication for failure mode and can be classify asductile failure mode mixed with flexural failure due topropagation of middle bottom crack up to failure (Ali,T., & Yehia, S., 2016) as shown in Figure (11) which isshows the crack of bottom of slabs.400 kg/m325Load (ton)201510Table 5: Experimental Results of Tested SlabSpecimens530DaysFigure 9: Relationship between Flexural Strength andConcrete Age using Different Cement ContentTable (5) and Figure (10) represent the ultimate loadfor polymer impregnated slab specimens versusdeflection. Changing the cement content has nosignificant effect on either the ultimate load ordeflection so that, it's recommended to use less cementcontent to be more economic without any significantlose in ultimate load capacity. The ultimate load rangedfrom 6.48 to 7.40 tons, while the maximum deflectionwas around 5mm. All three slabs showed the samebehavior of load versus deflection, where an elasticbehavior control the relationship curve up to crackingload, then resin (polymer material) effect becameapparent and modulus of elasticity increased. Finally,propagation of cracks increased and when the ultimateload was reached the failure occur with large deflectionrecord.As shown in figure (10), first crack in slab (S-1)occurred at load 2.09 tons and propagation increasedto load 3.10 tons then failure occurred at load 6.48 tonswith shallow cracks in middle bottom of slab. Cracks insecond slab (S-2) occurred at loads 2.20 tons and 3.00tons, respectively. Meanwhile, failure occurred at 6.80tons with deep cracks in middle bottom of slab. Threedifferent cracks occurred at third slab (S-3), the first atload 2.50 ton, second at load 3.60 tons then at load 4.90tons. Failure approximately occurred at load 7.40 tonsin middle bottom of slab which is the maximum valueof all three slabs. Cracks in (S-3) are more wide thanothers, this is due to lately state of deboning ofconcrete ingredients due to large cement content(strong cement paste) which happen suddenly infailure stage. The test of specimens can prove that,polymer filler material (resin) provide specimens morecapability of sustained load. The percentage ratiobetween ultimate loads to failure loads is 33% as anaverage value of tested specimens also, displacementductility factor recorded a value of 257% as an averageof tested specimens, this calculated values give anDisplacementDuctilityFactor (%)25Pcr/Pult (%)20Deflection(Ultimate)(mm)15Ultimate Load"Pult" (ton)10Cracking Load"Pcr" S-32.507.405.3634%209%S-1Load (ton)0Specimen0S-2S-3Deflection (mm)Figure 10: Relationship between Ultimate Load andDeflection for different Slab Specimens(a)638 International Journal of Current Engineering and Technology, Vol.7, No.2 (April 2017)
Sameh Yehia et alThe impact of using Polymer Impregnated Porous Concrete in Structural Engineering Applicationsimpregnated polymer concrete recorded 26, 27,30kg/cm2 for cement content 200, 300, 400kg/m3,respectively. The results show that, polymer concretetranscend in all cases of change of cement content inconcrete, and this proved by the increasing of loadcapacity with 1160%, 508%, 319% for studied cementcontents in comparison to virgin porous concrete.The use of porous impregnated polymer concrete isa new boom to improve the mechanical properties ofthe concrete, the obtained results confirmed that, usingthis polymer concrete will have a wide field in futureresearch, especially given that the use of concretewithout steel reinforcement bars has become thebiggest concern now.The new generation of reinforcing bars has becomeused fiber reinforced polymer bars. The materialswhich are used in polymer impregnated concrete aresubstantially identical with fiber reinforced polymerbars which lead to increase the bond between thesebars and the concrete ingredients to get a strong highquality concrete with very high mechanical propertiesin comparison to any other type of modern concretes.The following Figure (12) shows the variation ofnormal stress for different specimens and its seem tosay that, by increasing cement content the normalstress increase but according to mix design limitationsthe cement content can't increase more than 500kg/m3so that, the using of polymer (resin) is a good choice toimprove without increasing of cement content. Also byincreasing cement content the rate of improvementdecrease so that, the optimum value with unique costand high performance recorded at cement content200kg/cm2(b)Porous Impregnated Polymer ConcreteNormal Stress (kg/cm2)Porous ConcreteCement Content (kg/m3)Figure 12: Normal Stress Variations(c)Figure 11: Crack pattern for different Slab Specimens5. Theoretical Analysis for Tested SpecimensThe maximum normal stresses were calculated basedon obtained results in (Section 4.1.). This analysis wascarried out to study the internal effect of polymer(resin) on the concrete behavior to measure thecapability of its resistance to bending moment. It isworth mentioning that, normal stress of porous(Ali, T., & Yehia, S., 2016) and (Yehia, S. ,2015),there are one of them having a pilot specimen withsteel reinforcement area of 6.78 cm2 (6Y12/m') and theother, studied a virgin traditional concrete specimenwithout steel reinforcement bars, both of them testedunder pure bending moment and arising under theinfluence of the same processing of the studiedconditions in this research. Common ingredients ofconcrete proportions are used with cement content of350 kg/m3 in these papers. The specified cementcontent is limited to the same interval of studiedcement content in this research. By studying of theprevious results, normal stress values are 108 kg/cm2(with steel rebar's) and 34 kg/cm2 (without rebar's).These values are more than virgin porous concretevalues by 655% and 206%, respectively. On the other639 International Journal of Current Engineering and Technology, Vol.7, No.2 (April 2017)
Sameh Yehia et alThe impact of using Polymer Impregnated Porous Concrete in Structural Engineering Applicationshand, the results obtained from this study inforced concrete capacity when usingpolymer impregnated porous concrete.Conclusions and RecommendationsThis paper seeks to expand the application of ering. Density of traditional concrete is higherthan porous concrete by 26% but permeability factorof porous concrete (as usual) is higher than traditionalconcrete by sixteen times. Although larger cementcontent (400kg/m3) achieved compressive strength of205kg/cm2 after twenty-eight days, this value is notgood deal in comparison to traditional concrete whichcan achieve approximately compressive strength of350kg/cm2 for the same cement content it’s need to doa unique idea to overcome low capacity of compressivestrength and this appear next below. Compressivestrength, indirect tensile strength and flexural strengthwere increased by increasing of cement content. Theincrease in cement content by 50kg/m3 can enhancethe properties of porous concrete by approximately288%, 383%, 324% for compressive strength, indirecttensile strength and flexural strength, respectively. It'sobserved that indirect tensile strength is compatiblewith the same percentage of compressive strengthvalue as traditional concrete but flexure strength is outof range compared to traditional concrete. Polymerimpregnated porous concrete is a suitable solution forfacing low compressive strength problem. Theexperimental results show that increasing the cementcontent can't improve the behavior of polymerimpregnated porous concrete slab but it can affect thefailure mode due to changing in displacement ductilityfactor because it’s gives a bond between ingredientsand delay the cracking mode to appear in early state.The ultimate load versus deflection of slabs was notchanged with different cement contents so that, itsrecommended to use less cement content (200kg/m3)to be more economic without any significant decreasein capability of sustain load. For the same cementcontent, the capacity of polymer impregnated porousconcrete increased by 188% of common unreinforcedconcrete and achieved 60% of virgin traditionalreinforced concrete.ReferencesAli, T., & Yehia, S. (2016). Study on Strengthening of RC Slabswith Different Innovative Techniques. Open Journal of .4236/ojce.2016. 64044Axim, I. G. (2006). Practical Application of Previous Concrete.In Rick Blackburn (Ed.) (pp. 1–20). NRMCA Conference.Bentz, D. P., & Sumanasooriya, M. S. (2010). Predicting thePermeability of Pervious Concrete Advances incharacterization of pore structure and transportproperties, (May), 35–40.BS: 5328, British Standard for Concrete Mix Design.BS: 12390, British Standard for Testing Hardened Concrete.J-FIX Polyester Resin, available at: fToy, H. C. (1924). the Permeability of Concrete. ICE .1680/isenp.1924.15131Viscocrete Admixture, www.sika.com, available ecfdbb368da6b294a8447d4e63/ViscoCrete.pdfW. R. Grace&Co.-Conn. (2006). Pervious Concrete MixProportioning, 0–1.Yehia, S. (2015). Behavior of Fibrous Light Weight Concretein Comparison to Traditional Fibrous Concrete.International Journal of Innovative Science, Engineering &Technology, 2(5), 113–119.640 International Journal of Current Engineering and Technology, Vol.7, No.2 (April 2017)
polymer impregnated porous concrete. Accordingly, resin was used to fill the voids partially in porous concrete to increase capability of sustained load, which will help to reliability use of this concrete in structural applications. 3.1.2 Details of Concrete Specimens The specimens of porous concrete were mixed with
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