Residual compressive and bond strengths of limestone aggregate concrete subjected to elevated temperatures

Concrete is exposed to elevated temperatures when subjected to accidental fires in buildings, or when is close to furnaces and reactors, as encountered in some industrial applications. Research studies indicate that a serious reduction in concrete strength may result in such cases, and that the type of aggregate used is an important parameter. In thus study, the influence of high temperatures (100–600°C) on the residual compressive and bond strengths of concrete made from limestone aggregates is experimentally investigated. The main test parameters involved were the maximum temperature, the time of exposure at the maximum temperature, the method of cooling, the age of concrete at the testing date, and the cement content. The results showed that exposure of limestone aggregate concrete to such temperatures may result in a noticeable reduction in its strength, especially in the range 400–600°C.