EXPERIMENTAL STUDY OF ENGINEERED CEMENTITIOUSCOMPOSITE MATERIAL FOR STRUCTURAL APPLICATIONAuthors:A. Tambusay, P. Suprobo, Faimun, A. A. AmiruddinProceedings of the 2ndMakassar International Conference on Civil Engineering(MICCE 2015) Makassar, Indonesia, August 1112, 2015 Civil Engineering DepartmentFaculty of Civil Engineering and PlanningSEPULUH NOPEMBER INSTITUTE OF TECHNOLOGYSurabayaOUTLINESIntroductionResearch ObjectiveMaterialsExperimental ProceduresResults and DiscussionConclusionINTRODUCTIONConcrete with high compressive strength have been commonly used for potential civilengineering application.Consideringthebrittlenessof concrete, thedevelopment of highperformancefiber-reinforced cementitious composites (HPFRCC) with high tensile ductility was carried out.EngineeredCementitiousComposite(ECC)isanewtypeof HPFRCCwithmoderatevolume fraction of fibers up to 2%.ECC addresses high tensile ductility with strain hardening behavior, thus the ultimatestrain of more than 2% through multiple micro-cracking can be achieved.ECC is also made using micromechanical concept, thus tight crack widths occurs in ECCless than 80 m.ECC has high fracture toughness and isotropic properties.ECC material can be used on structural member to prevent bond-splitting failure.3/13RESEARCH OBJECTIVEInvestigating the behavior of ECC under direct tensile tests by using local materialsCompressivestrengthof ECCmaterial werepresentedinthispaperinordertovalidatetheproposedmixtureproportionforconcrete grade M45.Polyvinyl alcohol fibers (PVA) of 2% were employed in this studyas the reinforcing material for cementitious composites.4/13MATERIALSStandard Mixture Design for ECC MaterialCement, Fly Ash, Silica Sand, Water, Chemical Admixture (HRWR), Randomly PVA FibersNon-Standard Mixture Design for ECC MaterialCement, Fly Ash, Lumajang Sand, Water, Chemical Admixture (HRWR), Randomly PVA FibersDetail of Materials: Cement: Ordinary Portland Cement (OPC) Type I Fly Ash : Fly Ash Class F with Lime Content 15.24% HRWR : Concrete Additive from SIKA PVA Fibers : Produced by Nycon Corporation Sands : Average and Maximum Grain Size of 100 m and 200 m, respectively Diameter LengthYoungs modulusTensile strength Specific gravity38 micron 8.0 mm 40 GPa 1600 MPa 1.30Table 1 Mechanical and geometrical properties of PVA fiber5/13EXPERIMENTAL PROCEDURESMixture ProportionTwo appropriate cement based ECC mix proportion:1. ECC-S : ECC matrices employing Silica Sand2. ECC-L : ECC matrices employing Lumajang SandTable 2 Standard of mixture proportion for ECCECC (M45)FA/C 1.2W/CMa0.26S/C 0.8Cement (C), kg/m3570Fly Ash (FA), kg/m3684Sand (S), kg/m3455Water (W), kg/m3331Fiber (PVA), kg/m326HRWR, kg/m34.9CM: Cementitious Materials (cement + fly ash)6/13EXPERIMENTAL PROCEDURESCasting, Curing, and Testing of SpecimensCastingCompressive Test : 50 100-mm cylinderDirect Tensile Test: cross section dog-bone 25 25-mmCuringAfter24hoursof casting, all thespecimensweredemouldedandmoisturecured in plastic bag with a controlled temperature of 25 CTesting of SpecimensThe specimens were tested in uniaxial tension using MTS machine with 5 kNcapacity under displacement control at a rate of 0.01 mm/s.7/13EXPERIMENTAL PROCEDURESCross section dog-bone25 x 25-mmFig. 5 Setup of uniaxial tensile test8/13RESULTS AND DISCUSSIONDensity and Compressive StrengthDay Mix IDDensity (kg/m3)Compressive Strength (MPa)7ECC-S 2062.65 34.09ECC-L 2088.11 34.7728ECC-S 2088.11 48.70ECC-L 2139.04 49.67Table 3 Density and compressive strength of each mix9/13RESULTS AND DISCUSSIONUniaxial Tensile Performance0.01.02.03.04.05.00.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0Stress (MPa)Strain (%)Day 7Day 280.01.02.03.04.05.00.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0Stress (MPa)Strain (%)Day 7Day 28Specimen Type Tensile Strain (%) Tensile Strength (MPa)ECC-S after 7 days moist curing 3.56 3.71ECC-S after 28 days moist curing 3.44 5.11ECC-L after 7 days moist curing 3.34 3.35ECC-L after 28 days moist curing 3.31 4.67Table 4 Tensile properties of ECC (M45) at different agesFig. 6 Tensile behavior of ECC-SFig. 7 Tensile behavior of ECC-L10/13RESULTS AND DISCUSSIONTypical Cracks of ECC Dog-BoneFig. 8 The comparison of direct tensile performance between ECC-S and ECC-L0.01.02.03.04.05.00.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0Stress (MPa)Strain (%)ECC-SECC-L Initial Multiple Micro-Cracking Failure Mode11/13CONCLUSIONBased on the experimental results reported in this paper, the following conclusion are drawn:1. The compression strength at 28-day of ECC-S and ECC-L meet the standard of compressionstrength of mixture proportion for ECC (M45).2. The density for an ECC is slightly lower than conventional concrete due to the lack of coarseaggregate3. The tensile strength capacity of both ECC-S and ECC-L can achieve 10% of its compressivestrength.4. Thetensilestrainof ECC-SandECC-Lexhibitsthestrainhardeningbehaviorupto3.56%where it remains acceptable for an ECC. Thus, it is acceptable to be used in the structuralapplication.5. The multiple micro-cracking occurs on the ECC dog-bone specimens under direct tensile test.6. From the compression test and direct tensile test, it can be confirmed that ECC-S has lowercompressive strength than ECC-L. However, in term of direct tensile performance, ECC-S hashigher tension strength than ECC-L.12/13THANK YOUHave a Nice Day and Enjoy MakassarCivil Engineering DepartmentFaculty of Civil Engineering and PlanningSEPULUH NOPEMBER INSTITUTE OF TECHNOLOGYSurabayaProceedings of the 2ndMakassar International Conference on Civil Engineering(MICCE 2015) Makassar, Indonesia, August 1112, 2015