The study on the bonding properties of shape memory alloy fiber and cement mortar

Studying the interfacial bonding properties between fiber and cement mortar is of paramount importance to elucidate the mechanism of fiber‐reinforced concrete. In this study, the pull‐out test of shape memory alloy (SMA) fiber and cement mortar under a monotonic load is carried out. The effect of different factors on the mechanical properties of bond‐slip is investigated. The ultimate bond strength prediction model, the critical embedding length formula, and the bond‐slip model have been proposed for SMA fibers and cement mortar. The experimental findings indicate that the bond strength increases as the strength of the cement mortar matrix increases, the embedding length of the fiber decreases, and the complexity of the end shape increases. Of these, the variation in the shape of the end of the fiber has the most significant effect. The ultimate bond strength for the wavy fiber is 476.92% higher than that of the straight fiber pull‐out specimen. Through the critical embedding length formula, the critical embedding length of ordinary straight SMA fiber is 77.2 mm. The multi‐factor constitutive model of bond‐slip built is capable of more accurately simulating the entire process of stress and failure.