Non-destructive methods to evaluate the self-healing behavior of engineered cementitious composites (ECC)

Research on the self-healing ability of engineered cementitious composites (ECC) with excellent strain tensile and multi-cracking capacity is a hot topic. In the paper, both non-destructive methods and destructive method are employed to trace the self-healing process of ECC in wet-dry cycles, which are ultrasonic measurement, sorptivity test and electrochemical test and direct tensile test, respectively. The ultrasonic speed, sorptivity coefficient and electrochemical impedance spectroscopy (EIS) show that the first five wet-dry cycles have obvious effect on self-healing of ECC. Moreover, EIS has a good agreement with the results of ultrasonic speed, sorptivity coefficient. Additionally, the self-healed cracks are filled with the abundant white substances along the crack, which are calcium carbonate and calcium hydroxide. In the predictable future, the non-destructive methods, especially EIS, could be used to monitor the working status of ECC in harsh environments and prolong the service life in civil engineering. (C) 2019 Published by Elsevier Ltd.