Acoustics Emission Characteristics of Damage of Recycled Aggregate Concrete Under Cyclic Loading

In earthquake-prone areas, concrete structures are often subjected to cyclic loads. In order to study the compression damage characteristics of recycled aggregate concrete under cyclic loading and unloading, uniaxial compression tests were carried out on concrete specimens with diffe-rent replacement rates of recycled coarse aggregate. Based on acoustics emission(AE) technology, dynamic analysis was made on the damage characteristics of recycled aggregate concrete during the whole process. The results show that:Kaiser effect exists in the acoustic emission ring count of recycled aggregate concrete under cyclic loading, which not only reflects the damage degree of materials, but also reveals the damage mechanism of recycled concrete with different replacement rate, with the increase of stress level, Felicity ratio decrease, Felicity ratio < 1 as a sign of serious damage of concrete; the fractal analysis of each cyclic AE ringing diagram shows that the fractal dimension of recycled concrete AE ringing increases with the increase of the number of cycles under cyclic loading, which proves the feasibility of applying AE in damage prediction. Based on the study of cumulative AE events by using the response ratio theory, it is concluded that AE response ratio Y decreases with the increase of the stress level of the specimen under regenerated concrete loading and unloading, and when the response ratio Y decreases to about 1, it can be regarded as a precursor to the failure of regenerated concrete, providing a reference for engineering damage prediction and safety assessment. © 2021, Materials Review Magazine. All right reserved.