Experimental investigation on pullout strength of hybrid reinforcement of fibre in rubberized cementitious composites

Optimization using the response surface methodology (RSM) for the pull-out strength utilizing partial replacement of crumb rubber with the sand along with the incorporation of hybrid fibers such as PVA (Polyvinyl alcohol) and tirewire in engineered cementitious composites (ECC). The crumb rubber in ECC produced the lower pullout strength however ensured the homogeneous dispersion of fibers. Hybrid fibre combination of did not affect the pull-out strength either positively or negatively. The relation between compressive strength and pull-out strength have been worked out through regression analysis with R² value of 0.879. RSM aided in optimizing the ingredients in the ECC to achieve better performance of the ECC material. RSM optimized results using ANOVA (Analysis of variance) was experimentally verified and it was found that less than 5% of the difference in the results with the desirability of 1.