Modelling of the pre and post-cracking response of the PVA fibre reinforced concrete subjected to direct tension

Abstract

The strain-hardening response is always associated with high performance fibre reinforced composites in which coarse aggregates are completely eliminated. However, the use of higher binder content, cost and relatively low modulus of elasticity limit their structural application. In this study, the response of conventional high performance fibre reinforced concrete (HPFRC) with coarse aggregates containing polyvinyl alcohol (PVA) fibres under direct tension has been observed. The models were proposed and validated through experimental investigation. Total three mixes of concrete having same binder content with macro size polyvinyl alcohol (PVA) fibres were investigated. Metakaolin and silica fume were used as 10% cement replacing material in two of the mixes to minimise the cement content and to optimise the bond strength of the fibres with lower binder content. Single fibre pull-out test was also performed to observe and develop the relation of the post-cracking response of the fibres and matrix. It was found that concrete in the presence of PVA fibres attained strain-hardening response with a drop in the load up to 50% of the peak load and the strain capacity of about 2% under direct tension. The post-cracking relation based on single fibre pull-out test closely matches the results of direct tension test.