Fire Behavior of High-Performance Concrete Made with Silica Fume at Various Moisture Contents

Behavior of high-performance silica fume concrete with various moisture contents in the International Standards Organization (ISO) standard fire was investigated. Spalling test results from 100-mm cube specimens revealed that moisture content and strength are the two main factors governing explosive thermal spalling of concrete. Moisture content has a dominant influence on spalling. The dependence of spalling on moisture content and strength confirmed the vapor pressure mechanism of spalling. Spatial distribution of rebound hammer test results on postfire concrete slabs correlated with the temperature field within the slabs. Conventional methods do not properly describe the residual mechanical properties of concrete subjected to fire. A new method is needed that considers the chemical and physical changes inside concrete caused by elevated temperature.