FIRE PERFORMANCE OF HIGH STRENGTH CONCRETE: RESEARCH NEEDS. APPLIED TECHNOLOGY IN STRUCTURAL ENGINEERING

A compilation of fire test data which shows distinct behavioral differences between high-strength concrete (HSC) and normal strength concrete (NSC) at elevated temperature is presented. The differences are most pronounced in the temperature range of 20 °C to 400 °C. What is more important is the observed explosive spalling of HSC specimens during fire tests.. A comparison of test results with current code provisions on the effects of elevated temperatures on concrete strength shows that the CEN Eurocodes and the CEB provisions are unconservative. Aspects of analytical modeling for predicting the buildup of internal pressure during heating are discussed. The paper concludes with recommended research needs, identified at a workshop on fire performance of HSC, convened at NIST in February 1997.