Strength and stiffness of concrete under heating and cooling treatments

Understanding the properties of concrete under high temperature is essential to enhance the fire resistance of reinforced concrete structures (RCS) and to provide accurate information for fire design of RCS. During and after a fire, different parts of a concrete structure experience different heating and cooling scenarios. Hence the remaining stiffness and strength properties in the concrete structure need to be assessed before a decision can be made as to whether the structure can be repaired or must be rebuilt. The purpose of this study is to investigate the strength and stiffness performance of concrete subjected to various temperature scenarios with the aid of residual compressive strength testing. In addition, the temperature distribution in the concrete cylinders, color changes, and cracks are investigated.