| 摘要 |
PROBLEM TO BE SOLVED: To provide a waterproof sheet used in tunnel and other construction work that facilitates determination on whether repair is needed on a damaged portion and a scale of the repair work, thereby enhancing work efficiency, by improving accuracy of detection of surface area and depth of the damaged portion occurring in the waterproof sheet.SOLUTION: A waterproof sheet includes a non-permeable sheet of a long belt-like form having at least three color-coded thermoplastic resin layers laminated and integrated, namely, a surface layer, a safety layer, and a critical layer, in that order. The non-permeable sheet has a combination of black and white specified for the surface layer and the critical layer, and a cold color specified for the safety layer located therebetween. A long permeable sheet of an almost the same belt-like form as the critical layer of the non-permeable sheet is placed on the critical layer surface, and the two sheets are bonded entirely or partially except for edge parts along the two long sides of the two sheets.SELECTED DRAWING: Figure 1 |
