Effect of Chloride and Corrosion of Reinforcing Steel on Thermal Behavior of Concrete and Its Modeling

Abstract

Chloride induced corrosion of reinforcing steel is a significant problem. Non-destructive technique to inspect the corrosion of reinforcing steel is required. Thermograph is one of the Non-Destructive Testing methods which may be useful for detecting corroded bar in reinforced concrete. This study aims to investigate the thermal behavior of concrete influenced by chloride and corrosion of reinforcing steel at different corrosion levels. The results of thermal behavior of chloride and corrosion product contaminated concrete are useful for determining the detectability of corrosion by thermograph. Different mix proportions of concrete and also level of corrosion were studied. The results of temperature profiles obtained from experimental work proved that when there is presence of dense rust confined at the interfacial zone between concrete and steel, thermal behavior of concrete around steel bar changed. The results revealed that when applying heat source on the top surface of the specimen, there was a slight change of temperature on top of corroded bar while there was more signification change of temperature below the corroded bar. This is because the dense rust with low porosity is a better heat conductor when compared to concrete, transferring the heat faster to the part below the rusted bar.