Influences of Latex on Tensile Behavior of PVA Fiber-reinforced Cementitious Composites

The tensile properties of latex-modified cementitious composites reinforced by PVA fiber are reported in this paper. Direct tensile tests were performed to investigate the effect of latex on tensile strength (sigma), strain (epsilon) and fracture energy of the composites. The results indicate that latex incorporation diminishes the tensile strength with a maximal strain of 0.57% but contributes to the enhancement of fracture energy. Under standard curing conditions (RH>90%, 20 degrees C +/- 1 degrees), sigma and epsilon of specimens after 14days curing reach half value of 28days curing ones. Multiple-cracking was observed when the ratio of solid polymer to cement (P/C) is about 0 1. PVA fibers were pulled out more easily at the presence of polymer film formed by latex, which can be the third way to adjust the interfacial bonding between PVA fiber and matrix.