Development of response surface models for self-compacting hybrid fibre reinforced rubberized cementitious composite

Abstract

Despite the excellent beneficial mechanical properties and durability behaviour of cementitious composite, the modulus of elasticity is low due to the absence of coarse aggregate and this has hindered in the lone application in structures. The addition of steel fibres in the form of Tirewire along with the PVA (polyvinyl alcohol) as hybrid fibre in cementitious composite, with proper volume of high and low modulus fibers is expected to improve tensile stresses, modulus of elasticity and meanwhile balancing the strain capacity. The partial replacing the fine aggregate with the crumb rubber is to ensure the dispersion of fibres and to limit the fracture toughness of the matrix to improve the performance. The mix designs have been developed using response surface methodology (RSM). The fresh properties for self-compacting were studied and detected that Tirewire diminishes the workability and was conserved through PVA fibre, crumb rubber and superplasticizer. The various hardened properties such as, direct tensile strength, flexural strength and modulus of elasticity was optimized by developing the model equations through analysis of variance (ANOVA). The results revealed that the Tirewire fibre has enhanced the tensile strength, flexural strength and modulus of elasticity. The optimization mixtures were obtained based on the RSM results and are experimentally validated with the less than 5% of error.