Fracture features of calcium carbonate whisker-based composites under freezing and thawing cycles using semi-circular bend test

Calcium carbonate whiskers (CW) showed good cracking resistance at the microscale. In this research, four different CW volume fractions (1.0%, 1.5%, 2.0%, and 3.0%) were added into cement mortar. The purpose was to further investigate the fracture behavior by using a semi-circular bend test (SCB) of SCB-CW after different freezing and thawing cycles (0 cycles, 25 cycles, 50 cycles, 75 cycles, and 100 cycles). In addition, three analytical models of SCB-PM and SCB-CW were established to predict the stress-strain response after different freezing and thawing cycles. The experimental results showed that the lowest mass increment, electric flux, highest residual flexural strength, fracture toughness, and fracture energy after different freezing and thawing cycles were observed in SCB-CW3.0. It was observed from the experimental results that only model II completely satisfied its basic requirements and its parameter c was closely correlated with the number of freeze-thaw cycles and the CW volume fraction. Highlights Calcium carbonate whisker is added to enhance the fracture behavior of mortar. The different freezing and thawing cycles are considered. The results are obtained using semi-circular bend test and analytical models are established. The highest fracture parameters are observed in SCB-CW3.0 under different freezing and thawing cycles. The model II is suggested for predicting the experimental response of composites.