Effects of fibre hybridization on multiple cracking potential of cement-based composites under flexural loading

The effects of individual and combined additions of polypropylene (PP) and polyvinyl-alcohol (PVA) fibres (PP/PVA fibre ratios: 3/0%, 2/1%, 1.5/1.5%, 1/2% and 0/3%) on the flexural behaviour of cement-based composites have been investigated. For this purpose, matrices at different strength grades have been used. The binder composition of high strength matrix (MI) was solely cement and 50% of cement was replaced with fly ash to prepare a comparatively low strength matrix (Mil). Thirty prismatic samples are subjected to four-point flexural loading after 28 days of standard curing. The load mid-span deflection curves have been plotted and simultaneously cracking patterns of composites have been photographed at definite deflection values. First cracking and flexural strength, deflection and relative toughness values have been determined for all samples