Evolution of pore structure of microcapsule self-healing concrete during ultrasonic triggering

To investigate the microstructure of self-healing concrete before and after ultrasonic triggering, mercury intrusion porosimetry (MIP) test and industrial CT technology were applied to analyze the pore structure of self-healing concrete. The results show that ultrasonic triggering, on one hand, can improve the triggering of microcapsules, reducing less harmful pores, harmful pores and extremely harmful pores. On the other hand, excessive ultrasonic triggering will slightly damage the microstructure of self-healing concrete. The total porosities of self-healing concrete with 6 % microcapsules after ultrasonic and mechanical triggering were 8.6 % and 15.9 %, respectively. The simulation results of porosity are consistent with the MIP results (8.7 % and 15.6 %, respectively). The gray values of microcapsules and the cement matrix are 55 and 126, respectively. Finally, based on the CT reconstruction simulation, the substrate fluid velocity after ultrasonic triggering is lower than that triggered by mechanics.