The analysis of acoustic emission signals detected during the loading of cement-based materials

The article deals with the experimental investigation of changes in the internal structure of materials subjected to loading. The main aim of the experiments was to identify crack formation and their propagation within the elastic part of the stress-strain diagram and define its significance and influence on the overall failure behaviour of specimens under loading. The specimens' overall behaviour was monitored using the non-destructive testing method of acoustic emission (AE). Three different cement-based composites, which differed mainly in the maximum value of the expected static modulus of elasticity, were manufactured for the purpose of experiments. Based on the results, it can be stated that the increased number of micro-cracks in the specimens' internal structure is reflected in an increased number of AE events. The specimens with a lower value of the static modulus of elasticity showed higher AE activity during all the periods of loading being investigated. In addition, the AE energy released due to the formation of micro-cracks was the highest in specimens with a lower value of the modulus of elasticity.