Effect of initial crack‐depth ratio on fracture characteristics of FRP‐strengthened concrete

Abstract

AbstractTo investigate the fracture characteristics of FRP (fiber‐reinforced polymer)‐strengthened concrete, three‐point bending tests were carried out on concrete specimens with different initial crack‐depth ratios. The effects of the different crack‐depth ratios on the fracture parameters were analyzed, and the correlation between the crack‐depth ratio and the fracture parameters was verified quantitatively. The test results reveal that there are three critical points in the damage process: the crack initiation point, first peak point, and ultimate bearing capacity point. With the increase of the initial crack‐depth ratio, the crack initiation load decreased, but the first peak load and ultimate load first increased and then decreased. The stress intensity factors of the three points also first increased and then decreased. Additionally, the damage variable decreased with the initial crack‐depth ratio increased. The increment of the critical crack‐depth ratio and the flexibility coefficient are related to the initial crack‐depth ratio.