Effect of crystalline admixture and superabsorbent polymer on the self-healing and mechanical properties of basalt fibre mortars

Abstract

ABSTRACT This study investigated the effects of a crystalline admixture (CA) and superabsorbent polymer (SAP) on the self-healing and mechanical properties of basalt fibre mortars. Uniaxial compression experiments were conducted on basalt fibre mortar specimens to investigate the effects of the two admixtures and different admixture ratios on the strength repair ability of basalt fibre mortar at different maintenance ages after pre-cracking, and microscopic observations of cracks and their healing products were conducted using optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy to verify the experimental results. The results showed that CA has a noticeable advantage in the self-healing of microcracks by producing a dense material through chemical reactions, whereas SAP can effectively fill wider cracks and reduce their width through physical expansion. Compared with CA, SAP had a greater effect on the compressive strength of the basalt fibre mortars. The simultaneous dosing of CA and SAP in appropriate amounts can effectively combine the advantages of CA and SAP to optimise the self-healing effect of basalt fibre mortars, generating self-healing fillers based on calcium silicate and calcium carbonate in the cracks and enhancing the repair strength of basalt fibre mortars with a self-healing rate of 103%.