The Effect of High Temperatures on the Mechanical Properties of Concrete with Different Strengths at Different Mixing Ratio

Abstract

This research work includes an experimental study of the mechanical properties , as compressive strength, tensile strength, modulus of elasticity, and stress – strain relation for ordinary concrete. Different mixes of different cement content and W/C ratio considered at different high temperature. Nine different concrete mixes for different cement content and W/C ratio are exposed to four steps of high temperature (20, 200, 400, 600)°C for a duration of one hour. The results show that heating the concrete samples reduces the mechanical properties of the samples in a different percent for different mixes. The affect of high temperatures to modulus of elasticity , splitting tensile strength and compressive strength for concrete are different and various. It has been found that the concrete mixes of low strengths (a few cement and high W/C ratio) maintains compressive strength more than concrete mixes which have high strength (rich cement and low W/C ratio) when exposed to high temperatures. This effects generally vary from mix to another in some or all properties. In general there are less effect at (200°C) degree, then the changes become more sensitive at higher temperature ( 400, 600)°C.