Abstract
In this study, new repair methods based on crack self-healing technologies were suggested in order to prevent water leakage in underground civil infrastructure such as tunnels. First, shotcrete with self-healing capability was examined in comparison with normal shotcrete without self-healing capability. The results of water pass test after cracking show that cracked shotcrete concrete mixtures incorporating self-healing agents exhibit much higher self-healing behavior than in cracked normal shotcrete concrete mixtures. For new repair materials with self-healing capability based on crack injection method, various repair materials were observed. Cracks with an initial width of 0.2mm in the case of some mix proportions were almost healed after water passing tests. Finally, the effects of various hydration phases on the self-healing mechanism were analyzed using TG-DTA, Digital Microscopy and SEM（EDS）. From these concepts, some particular mix-proportions for new repair method with self-healing capability were suggested.
