Investigation of Thermal Damage and Structural Weakness in Concrete

Abstract

This study investigates the impact of high temperatures on the structural and physico-chemical properties of concrete, emphasizing the degradation of material strength under fire exposure. Through a review of reference data, it was confirmed that elevated temperatures significantly reduce concrete strength, potentially leading to structural failure. The rebound hammer method, a mechanical non-destructive testing technique, was selected for on-site evaluation due to its accessibility, speed, and ability to provide immediate preliminary results. Field measurements conducted at fire-affected sites allowed for the identification of temperature zones and heat flow directions based on variations in concrete strength. Comparative analysis between intact and damaged areas enabled the identification of critically affected zones and the estimation of structural degradation. The study demonstrates that using the Schmidt hammer, with proper calibration and error consideration, provides reliable data for determining the origin of the fire and for making informed decisions on structural repair or reinforcement.