Mechanical properties and damage evolution behavior of coal–fired slag concrete under uniaxial compression based on acoustic emission monitoring technology

摘要

Slag waste can be effectively used to produce coal–fired slag concrete (CSC), which has economic and environmental benefits. However, CSC used in engineering construction will eventually be subjected to damage. The purpose of this study is to investigate the mechanical characteristics and damage evolution behaviour of CSC specimens under a uniaxial compressive load using acoustic emission (AE) monitoring technology. Through uniaxial compression testing and AE monitoring, the stress–strain curve and AE characteristics of CSC specimens are obtained. Subsequently, a damage evolution model of the CSC specimens under a uniaxial compression load is constructed, and the damage evolution characteristics of the concrete are analysed. The results indicate that an increase in the ratio of the coal–fired slag mass to the cement mass results in a gradual reduction in the compressive strength of the CSC. Moreover, the maximum value of the cumulative energy count and cumulative ringing count of the AEs gradually increases while the damage degree gradually decreases. The damage evolution process for CSC can be divided into three stages: the initial damage formation stage, accelerated damage growth stage, and damage failure stage. The damage model, based on the AE cumulative ringing count, reasonably reflects the damage evolution process of the CSC specimens. The results of this study provide a reference for theoretical research and the engineering application of CSC.