A probabilistic method of testing for the assessment of deterioration and explosive spalling of high strength concrete beams in flexure at high temperature

摘要

In the fire community there are a number of misconceptions, which have been inherited from previous work as far back as the early 1900. These have arisen from deterministic experiments by respectable research workers, which have been dogmatically followed over the years. So we have inherited a number of misconceptions as standard fire tests to simulate an actual fire. Vague terms such as spalling has been frequently been used which does not differentiate between violent failure termed explosive spalling and breaking of surface concrete. These two distinct phenomena are the result of quite different effects. Since a number of factors influence these type of failures under elevated temperature a non-deterministic series of tests on different types of high strength concrete have been carried out at City University, London. A number of factors known to affect explosive spalling have been selected at three different levels and the results have been examined statistically to assess the significance of the individual and interacting factors. The paper describes the approach and some of the results.