Characterization of bending performance of reinforced cementitious composites beams with hybrid fibers after exposure to high temperatures

The bending performance of reinforced beam containing steel fiber, polyvinyl alcohol (PVA) fiber, and calcium carbonate whisker after high temperature was studied. With the introduction of steel-PVA-whisker hybrid fibers, the thermal bursting and cracking of the reinforced beams were alleviated significantly. The peak load of reinforced beam was significantly increased with the introduction of 1.5 vol% steel fiber and 0.5 vol% PVA fiber. While the introduction of whisker led to decreased peak load and shear failure pattern of the beams, due to the decomposition of whisker at high temperature. The microscopic mechanism of action of fiber and whisker is discussed. A prediction model for the shear bearing capacity of reinforced beams with hybrid fibers after high temperature was proposed, considering the action of multiscale fibers and high temperature.