关键词: 湿筛混凝土, 单轴拉伸, 数字图像相关, 声发射, 损伤识别

Abstract: To investigate the crack development behavior of wet-screened concrete under uniaxial tensile test at various loading rates (1×10^-6、5×10^-6、25×10^-6 s^-1), a combination of acoustic emission (AE) and digital image correlation (DIC) was utilized to monitor the wet-screened concrete specimens in real time. Displacement-load curves, acoustic emission signals and crack location under different loading rates were obtained. The findings revealed that in the axial tensile process, the cumulative energy within the specimen increased with increasing loading rate, and the damage index of the specimen developed linearly. Meanwhile, the fracture of the specimens was mostly due to the failure of the surface between coarse aggregate and cementitious material, accompanied by the destruction of coarse aggregate. The fracture location of the aggregate highly corresponded with the AE energy signal. As the loading rate increased, the proportion of the primary crack displacement to the axial displacement of the specimen increased significantly, indicating a considerable strain concentration within the specimen.

Key words: wet screened concrete, uniaxial tension, digital image correlation, acoustic emission, damage identification