Experimental Study on Post-peak Cyclic Characteristics of Self-compacting Concrete Combined with AE and DIC Techniques

As a kind of concrete material, the self-compacting concrete (SCC) is usually subjected to external cyclic load after cracking. In this paper, three-point bending tests were carried out for SCC specimens with different notch-to-depth ratios. The whole loading process was monitored by acoustic emission (AE) technology and digital image correlation (DIC) method. The post-peak cyclic characteristics of SCC were analyzed, and the effects of notch-to-depth ratios on mechanical performance of SCC were explored. The change rules of acoustic emission energy, b-value and Ib-value were obtained by processing the collected acoustic emission signal data. Besides, the development law of internal damage for SCC specimens was elaborated and the active cracks were classified according to the ratio of RA value to AF. In addition, the strain field diagrams of specimens with notch-to-depth ratio were displayed and analyzed, and the propagation laws of effective crack length and crack tip opening displacement (CTOD) of SCC concrete with different notch-to-depth ratios were obtained based on DIC technology.