Investigation on single fiber pullout and interfacial debonding mechanisms with acoustic emission techniques

: Fiber pullout behaviour is of great significance in post-crack performance of steel fiber reinforced concrete. Firstly, in order to understand the debonding behaviour of the fiber/matrix interface during the pullout process, single fiber pullout tests are carried out in this study. Both hooked-end fibers and straight fibers with the same embedded length of 30mm are considered. Load versus relative displacement curves of different fiber type are studied. Secondly, to investigate the debonding behaviour along the interfacial zone, acoustic sensors are also applied. Based on the acoustic signal detected by the sensors attached on the concrete specimen, debonding mechanism is identified with parameter based AE signal analysis. Moreover, frequency and energy spectrum with regard to fracture behaviour of interfacial zone are further analyzed.