Influence of ultrasonic triggering parameters on recovery performance of microcapsule-mediated self-healing cement mortar

Abstract

This study investigated the recovery performance of cement mortar incorporating UF/E microcapsules subjected to ultrasonic irradiations at different frequencies and powers. Results showed that ultrasonic trigger mode was superior to mechanical trigger mode in both strength and durability repair efficiency. At fixed frequency and time, there was a threshold value of ultrasonic power density towards the strength and durability repair efficiency. An appropriate increase in ultrasonic frequency can also effectively promote repair efficiencies. Pore structure analysis showed that ultrasonic wave has a competing effect (healing and damaging) on self-healing mortars. With increasing the ultrasonic power density, the damaging effect gradually became more significant, which was the essential reason for having a threshold value of ultrasonic power density.