Effect of pre-debonding on crack bridging behavior of fiber-reinforced cementitious composite

Among the large variety of methods that have been applied to overcome the problems encountered in cementitious materials fiber reinforcement is gaining large attraction owing to the high tensile resistance exhibited by the fibers. For effective analysis of the post-cracking behavior of the fiber-reinforced materials, numerous researchers have studied analytical methods to predict the behavior of such composite materials based on the behavior of a single fiber. However, these methods failed to consider the change of the fiber interface occurring during the cracking process. Accordingly, this study proposes a fiber-bridging model that can consider the pre-debonding effect created in the cracking process. Analytical examples are presented to explore the effect of pre-debonding on the pull-out behavior of a single fiber and the bridging relation of the crack plane. Moreover, the behavioral difference is analyzed with respect to the type of fiber. The results reveal the dependence of the pre-debonding effect on the pull-out state, the stress of the fiber and, particularly, the influence of the eventual overstepping of the tensile strength during the increase stage of the stress.