Mechanical behaviour and acoustic emission characteristics of basalt fibre mortar rubble under uniaxial cyclic compression

•The incorporation of BF increased the compressive strength by 9.3%-14.2%.•The effect of BF on the fracture pattern of mortar rubble was discussed.•The Felicity effect was observed in the BF mortar rubble.•Based on damage mechanics theory, a intrinsic damage model of BF mortar rubble was developed. To investigate the effect of basalt fibre (BF) content on the mechanical behaviour and damage characteristics of mortar rubble under cyclic loading, uniaxial compression tests and cyclic loading and unloading tests were carried out on specimens fabricated with different BF volume fractions. Based on damage mechanics theory, a damage ontology model of BF mortar rubble was developed. The damage of BF mortar rubble under cyclic loading was identified and analysed using acoustic emission (AE) techniques, and parameters such as the Felicity ratio (FR), ratio of the RA (rise time/amplitude) and the average frequency (RA/AF), response ratio, b-value and peak frequency were used to characterise the failure mechanism of BF mortar rubble. The results of this study revealed that the incorporation of BF increased the compressive strength by 9.3%-14.2%. The response ratios of the initial cycles were 91.2, 53.4 and 24.4 when the BF content was 0.2%, 0.3% and 0.4% respectively. The incorporation of BF helps to delay the onset of critical damage values. The peak frequency signals are concentrated in the region of 50 kHz and 160 kHz. the 50 kHz frequency represents the appearance of fractures in the matrix and the 160 kHz frequency signal represents the occurrence of brittle fractures in the aggregate. The FR trend was a good predictor of damage to the mortar rubble. The damage mode of the mortar rubble changed from tensile fracturing to composite fracturing due to the addition of BF. The performance optimisation concept of mortar rubble proposed in this study provides a reference for the optimal design of BF mortar rubble and thus has a strong application value.