Abstract:
Extensive research has been conducted on the utilization of shape memory alloys (SMA) with shape memory effect and engineered cementitious composites with strain-hardening and multi-seam cracking characteristics in the field of engineering. The study was conducted through 25 sets of central pull-out tests under monotonic and cyclic loading to investigate the bond-slip behavior between ribbed SMA bars and engineered cementitious composite (ECC). The findings indicated two primary failure modes: pull-out failure and pull-out-splitting failure. The ribbed SMA bars demonstrate superior bond performance with ECC compared to smooth SMA bars. Increasing the cover thickness and enhancing ECC strength significantly improve the ultimate bond strength. Specifically, expanding the cover thickness from 2 d to 4.5 d results in a 31% bond strength improvement, while upgrading the matrix strength from E30 to E50 achieves a 30% enhancement. Conversely, enlarging the bar diameter from 6 mm to 10 mm reduces the ultimate bond strength by 23%, and extending the anchorage length from 5 d to 10 d causes a 28% reduction. Under cyclic loading conditions, the bond strength exhibits a 12% enhancement and demonstrates notable recovery characteristics. Through systematic analysis of experimental data, a constitutive bond stress-slip model and anchorage length formula were established specifically for ribbed SMA bars embedded in ECC.