Experimental Research on Tensile Strength Reduction of Concrete Caused by Microwave Irradiation

Abstract

In order to understand the law on concrete degradation induced by microwave irradiation, the experimental research is conducted in which the following works are completed. At first, the different concrete specimens are exposed to microwave of various power levels for various time periods, and then some specimen irradiated by microwave are cooled in air, the other cooled by spraying water. After that, the tensile strengths of the heated and unheated specimens are measured with Brazilian test method. According to the test results, the reduction of tensile strength of plain concrete and steel-fiber reinforced concrete induced by microwave irradiation is analyzed, and the relations between the tensile strength reduction and the microwave exposure time and the effect of microwave power level on the residual tensile strength of concrete are obtained. The experimental research shows that the tensile strength reduction of concrete induced by microwave irradiation is dependent on the concrete component, microwave exposure time, microwave power level, and cooling method after irradiation. It is expected that the findings in the paper will become the basis of the future research of concrete and rock degradation induced by microwave irradiation, and will aim in searching the new method of breaking concrete and rock more efficiently.