Acoustic Emission Characteristics and Dynamic Damage Constitutive Relation of Shale-Ceramsite Concrete Subjected to Loading Tests

Abstract

To reveal the damage evolution mechanism and dynamic mechanical performances of lightweight shale ceramsite concrete (LWSCC), the damage evolution process and dynamic impact characteristics of LWSCC were studied by acoustic emission monitoring and split hopkinson pressure bar (SHPB) testing. Results show that in the quasi-static unconfined compression test, the ringing count and energy value are closely related to the strain, and 60% strain is the transition point of the crack growth rate. The growth curve of acoustic emission events lags the stress growth. The inflection point appears at 65% strain of the stress-strain curve, and that in turn appears at 72% strain of the acoustic emission event-strain curve. With the increase of the strain rate, the stress peak, incident wave energy, absorbed energy, and specific energy absorption values all increase, and the strain-rate effect is obvious. Based on the monitoring data of acoustic emission, the damage evolution equation of LWSCC was established under uniaxial compressive testing, and the dynamic damage constitutive relation was constructed of LWSCC under high-strain-rate impact testing. The conclusions obtained in this study provide a theoretical basis for the design of antishock structures.