ON THE REDUCTION OF STRENGTH OF CONCRETE AND SUPERSONIC INSPECTION DUE TO TRIAXIAL COMPRESSIVE LOADING HISTORY

The damage of concrete cube was experimentally studied. The compressive strength, splitting tensile strength and ultrasonic velocity were measured before and after loading history, respectively. Based on the continuum damage mechanics theory, the reduction of compressive strength and splitting tensile strength denote the damage of concrete. The relationship between the damage and the descent of ultrasonic velocity due to triaxial compressive loading history was investigated. According to the fitting of experimental data, the evolution equation of damage was obtained. The damage is found to be in linear dependence relationship with the descent of ultrasonic velocity. It is concluded that, being an important nondestructive detection method, supersonic inspection is convenient and applicable to estimation of damage of concrete during loading history in engineering practice.