Mechanical,Hygric, and Thermal Properties of Cement-Based Composite with Hybrid Fiber Reinforcement Subjected to High Temperatures

The tensile strength, bending strength, water vapor diffusion resistance factor, gas permeability, thermal conductivity, specific heat capacity, and linear thermal expansion coefficient of a cement-based composite with hybrid PVA-fiber reinforcement are determined as functions of thermal pre-treatment, the loading temperatures being 600 °C, 800 °C, and 1000 °C. The experimental results show that the most important changes in all studied parameters occur between the unloaded state and the loading temperature of 600 °C and then between 800 °C and 1000 °C. Although seemingly high, these changes are still small as compared to many other cement-based composites. The positive effect of using PVA fibers for the high-temperature behavior of the studied composite can be seen mainly in their ability to prevent thermal spalling which is a serious deterioration effect for cement-based composites.