Abstract
Urban telecom tunnels in Japan measure approximately 600 km and many of them arealready twenty through thirty years old. Selection of the optimum material for repairing cracks and water leakages is one of the most crucial points. For the purpose of selecting the optimum concrete structure repair material, this study has clarified the advantages and disadvantages of the currently employed water leakage repair materials, and has found out that a new modified polyurea resin provides an excellent material for ensuring conformance to cracks and others. Thus, detailed test evaluation was conducted, and, based on the results of this evaluation, the material is being utilized at the worksite of actual urban tunnels forthe past few years, with the result that the validity of this material has been verified.
