Study on mechanical properties and damage evolution of mortar reinforced by mixing basalt, carbon and polyester fibres in pairs

Fibre-reinforced mortar (FRM) has attracted much attention owing to its excellent mechanical properties. To further explore the influence of blended fibres on the mechanical properties and damage evolution of internal cracks in FRM, the effects of blended additions of basalt fibre, carbon fibre (CF) and polyester fibre (PETF) on the mechanical properties and microstructure of mortar were investigated. The results showed that the addition of 0.75% CF and 0.25% PETF had the best effect on enhancing the compressive strength, flexural strength and splitting tensile strength of the mortar, with increases of, respectively, 44.5%, 53.6% and 70.9% compared with mortar without fibres. Correlation analysis of rise time/amplitude (RA) and average frequency showed that the synergistic effects of blended fibres made the expansion path of cracks in mortar more complex. The RA percentage in the mortar with 0.75% CF and 0.25% PETF was the highest, increasing by 19.9% compared with the mortar without fibres.