Acoustic emission characteristics and damage model of cement mortar under uniaxial compression

Abstract Cement mortar is a widely used construction material; its mechanical behaviour is affected by the proportion of its contents and external loads. Its health condition and damage evolution can be obtained by acoustic emission (AE) monitoring. In this study, uniaxial compression and AE synchronisation tests under different loading rates for cement mortar with different cement sand ratios are carried out. Considering that the specimen still has a certain bearing capacity after failure, the concept of critical damage was introduced to modify the statistical damage evolution equation, and the damage evolution equation was fitted by using AE energy data. Finally, a statistical damage constitutive model of cement mortar considering the compaction effect of cracks was developed, and the fitted results of the models were compared to experimental data. Results showed that the critical damage value of cement mortar is approximately 0.9, and the damage constitutive model under uniaxial compression can accurately describe the relationship between strength and deformation of cement mortar with different cement sand ratios and loading rates.