Flexural toughness of strain hardening cement-based composites

Durability of cement-based composites such as normal mortar or concrete is usually limited due to low tensile strength,poor toughness and hence low resistance with respect to crack formation. The effect of inclusion of polyvinyl alcohol (PVA) fibers in Engineered Cement-based Composites (ECC) which are more recently called strain hardening cement-based composites (SHCC) has been studied. Flexural strength under four-point bending has been determined on samples made of fine mortar containing 0, 0.75, and 1.5 Vol. % of PVA fibers. The flexural toughness index according to ASTM method and the coefficient of the flexural toughness based on JCI method have been evaluated. It can be concluded that the maximum load bearing capacity and the maximum deflection of cement-based composites under four-point bending increase with increasing PVA fiber content. This observation can be explained by pronounced strain hardening of the fiber reinforced material. Comparison with numerical simulation confirms the obtained results.