Effects of High Temperature on Mechanical Properties of Polyvinyl Alcohol Engineered Cementitious Composites (PVA-ECC)

摘要

The influence of elevated temperatures on the mechanical properties of polyvinyl alcohol engineered cementitious composites (PVA-ECCs) was investigated in this study. A comparison of the compressive strength, flexural strength, compressive strain capacity, and modulus of elasticity of specimens with/without PVA fiber (volume dosage of PVA fiber: 2%) was conducted. The microstructure of PVA-ECC exposed to different high temperatures was studied using scanning electron microscopy (SEM). Based on previous thermal analysis tests of PVA fibers, all specimens were subjected to 20, 100, 200, 300, and 400 °C for 6 h. The experimental results showed that the compressive strength, flexural strength, and modulus of elasticity decreased as the temperature increased, whereas the compressive strain capacity increased with temperature. PVA incorporation significantly increased the flexural strength initially but accelerated the rate of strength reduction at high temperatures. The investigation of the PVA-ECC microstructure provides a fundamental reason for the decrease in the macro-mechanical properties. These findings provide guidance for the engineering applications of PVA-ECC to resist high temperatures.