A simple method to evaluate the depth of concrete degradation by fire

Abstract

A method was developed to estimate the depth of concrete degradation caused by a fire using the rebound number measured with a compact Equotip hardness tester. The method was experimentally verified by measuring a core taken from a concrete specimen heated according to the RABT curve to confirm the distribution of the rebound number from the heating surface. The results were then compared with the distribution of the residual compressive strength estimated from the heated temperature of the concrete specimen and further measured with a core taken from the specimen. This confirmed that the distribution of the damage depth of concrete can be simply estimated by measuring the rebound number of test pieces obtained by cutting a core sample in half. The distribution of the damage depth coincides with the distribution of the measured compressive strength and the residual compressive strength estimated from the temperature data obtained in the fire resistance test.