Experimental investigation on flexural and compressive toughness of mortar and concrete with hybrid toughening materials

Abstract

In this work, the effects of hybrid toughening materials on the flexural and compressive toughness of cement-based materials were studied experimentally. In specific, mortar and concrete specimens incorporating multiple toughening materials, including PVA fibers, rubber particles, and polymer latex powders, were designed and manufactured. The flexural load–deflection response and compressive load–displacement behavior of these prepared mortar and concrete specimens were tested, and then were analyzed with special attention to the influences of hybrid toughening materials on the flexural toughness index and compressive energy absorption index. In addition, the mechanism of toughness enhancement was discussed. The results show that, compared with the addition of PVA fibers only, the hybrid of multiple toughening materials could considerably improve the flexural toughness of mortar and concrete, while it had an insignificant effect on the compressive energy absorption index of mortar and concrete. After incorporating hybrid toughening materials, the toughening effects on the flexural toughness of concrete specimens were better than those of the corresponding mortar specimens. As detected from scanning electron microscopy images, the incorporation of hybrid toughening materials could promote the formation of network structures with a good capacity for crack resistance. This resulted in multiple ways for energy dissipation, and consequently enhanced the flexural toughness of cementitious materials.