Characteristics Evaluation of Acoustic Emission Behavior affected by Crack Angle and Distribution in Concrete Core Samples

Abstract

The mechanical properties of concrete are deteriorated by the development of cracks with a change in the stress-strain curve. In this study, concrete core samples were taken from in-service drainage facilities with developed cracks. The geometrical properties of cracks are evaluated by Acoustic Emission (AE) generation behavior based on compressive stress field. AE is quantitatively evaluated by SiGMA analysis, which evaluates the source location and its dynamic motion. The geometric properties of the cracks are visualized by X-ray CT and the crack angle relative to the loading direction is quantified. As a result, low frequency AE events are detected near vertical cracks. High frequency AE events are not detected same trend, which are located near horizontal cracks. It is presumed that this difference is due to the expansion of existing cracks and the propagation of cracks occurring depending on the crack angle. These results suggest that the crack propagation behavior under compressive stress changes depending on the crack angle.