Effect of varying water cement ratio on modulus of elasticity of high-performance fibre-reinforced concrete (HPFRC)

Abstract

This experimental study investigates the outcome of varying water-cement ratios on the modulus of elasticity of HPFRC and the optimization of the water-cement ratio. This study compared modulus of elasticity by using LVDT, UPV and stress–strain relation graph and developed modulus of elasticity equation for HPFRC. The water-cement ratio is taken as the variable. This was accomplished by observing the casting of HPFRC with partial substitution by metakaolin and fly ash. To test the mechanical properties of HPFRC and NC (Normal concrete) specimens with variable water-cement ratios, such as compressive strength and modulus of elasticity.Compared to normal strength concrete, HPFRC (High-Performance Fibre-Reinforced Concrete) shows compressive strength increment and decreases trends in deformations before failure. Hook ended Steel fibre having a length of 50 mm and 0.75 mm diameter used with 2%, 3%, and 4% by volume. The variation of water-cement ratio used as 0.2,0.25,0.3,0.35, and 0.4. The superplasticiser used was 1.5 percent for all mixes of HPFRC. The compressive strength and modulus elasticity of HPFRC were obtained higher values after 28 days for 2%, 3%, and 4% of fibre replacement with a w/c of 0.25 as 91.9, 94.8, 96.1 MPa and 40400, 42400, 43672 MPa, respectively. The dynamic modulus of elasticity and compressive strength of HPFRC had a significant relationship, with R2 = 0.8782. The findings of the HPRPC tests revealed a greater positive relationship between compressive strength and dynamic modulus of elasticity.