Experimental Study of the Working Stress State of Concrete Frame Structures through Ultrasonic Testing

Abstract

This paper studies the impact of different locations including frame columns, frame beams and nodes to ultrasonic velocity through performing ultrasonic testing of single-layer and single-span reinforced concrete frame structures; and analyzes the change rule of stress state of test pieces and ultrasonic velocity under different stress processes. This paper also establishes the baseline stress test curve of the concrete frame structures based on test data. The study shows that the change of velocity of tensile zone of the simple bending sections of the frame beams is larger than that of the compressive zone when the structures reach ultimate stress; the drop of ultrasonic velocity of locations in shear-bending sections is relatively smaller. As for frame columns, the velocity change of locations that are near the nodes is the largest; and for the frame, nodes have the most obvious impact to the ultrasonic velocity and the drop of ultrasonic velocity is the largest.