Investigation of New Repair Countermeasure Methods Using Crack Self-healing Technologies for Water Leakage Prevention on Subway Tunnels

Abstract

In this research, the application of repair methods of water leakage cracks using self-healing technologies for subway tunnels is presented from the Tokyo Metro (Subway) system. From the previous researches, effects of quick setting agents and water-stop agents with self-healing agents were investigated under various crack repair methods such as surface treatment repair method, injection method and V-cut repair method. The results showed that the proposed water leak repair methods using self-healing repair materials were effective under the subway tunnel conditions. Furthermore, experiments of new patching mortars including self-healing agents were conducted for performance estimations in the laboratory and field application. In order to apply these new repair materials in subway tunnels, water leakage cracks with Maximum 1.5 mm width from wall or ceiling of subway tunnels were selected. And then, new two repair construction method using quick setting agents and patching mortars were conducted. From these results, it was also confirmed that the sealing effects of water leakage through the penetrating cracks from these tests could be improved by inorganic repair materials with self-healing capability. Especially, these patching mortars were fully satisfied with the Tokyo metro’s repair materials standard code such as early and long term strength, the higher resistance of mass transfers compare to existing repair materials. Therefore, it is considered that the utilization of self-healing agents has a high potential for one of new repairing methods of cracked concrete under the water leakage for subway tunnels. The long term durability will be monitored continuously and studied.