ABSTRACT:The thermal properties of cement-based materials have gained more attention not only for the thermal analysis but also for the application of Non-Destructive Tests for building, bridge and other structures. Presence of chloride ions in pore structure was also found to affect thermal properties of concrete. This paper aims to study effects of chloride content on thermal properties of concrete. Specimens were submerged in sodium chloride solution for different period of time. Then, they were subjected to the heating test. It was found out that temperature of specimens with presence of chloride ions in pore solution increased faster compared to specimens without chloride contaminations. As the amount of chloride content in pore structure increased, concrete temperature also rose faster. The results obtained from this study can be used to accurately estimate thermal properties of concrete so that thermal analysis and application of Non-Destructive Tests such as Infrared Thermography can be effectively implemented.

Chloride induced corrosion of reinforcing steel is a significant problem. 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. The results of this thermal behavior are useful for determining the detectability of corrosion by thermograph. Different mix proportions of concrete and level of corrosion were studied. The results of temperature profiles obtained from experimental work proved that when there is presence of dense rust confined between concrete and steel, thermal behavior of concrete around steel bar changed. When applying heat source on 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 it. This is because dense rust with low porosity is a better heat conductor when compared to concrete. The temperature history obtained from simulation and experiment are in a good agreement. Numerical simulation provides quite good results in the area closing to the concrete top surface (depth 0.5cm and 1.5cm) and the accuracy of the estimated temperature is within 2%-5% of the experimental results.