Spalling mechanism and fire resistance of high performance silica fume concrete with different moisture contents

摘要

Concretes of five strength grades were used to investigate the behavior of high performance silica fume concrete with different moisture contents subjected to the ISO standard fire. The results obtained from the 100 mm cube specimens revealed that moisture content and strength grade are the two main factors governing the explosive thermal spalling behavior of concrete. Moisture content has a dominant influence on the occurrence of spalling. The dependence of spalling on moisture content and strength grade confirmed the vapor pressure build-up mechanism of spalling. That no spalling occurred during the fire test of slabs HPC060 and HPC-110 is ocnsistent with the test results obtained with 100 mm cube specimens.