WATER CUT-OFF STRUCTURE AT END OF SHEATHPIPE AND COMPOSITION FOR FORMING WATER CUT-OFF PART USED THEREFOR

PURPOSE:To prevent water permeability any hence enhance the lifetime of a cable by installing a water cut-off part to both ends of a sheath pipe which internally mounts a tension cable which constitutes a grand anchor and filing up a composition having cold resistance and shape follow up properties made of thermal plastic elastmer and natural resin or the like thereinto. CONSTITUTION:A water cut-off part 8 is installed to the tip 106 of a corrugated pipe 1 which internally mounts a tension cable 2 while a water cut-off part is also installed to the rear end 107. The water cut-off parts 8 at the front and the rear are filled up with a composition comprising styrene group elastmer or ionomer's thermal plastic elastomer 15 to 30wt.% natural resin 20 to 40wt.%, petroleum resin 20 to 40wt.%, adhesive resin 5 to 10wt.% and wax 5 to 10wt.%. They are protected from breakage induced by expansion, contraction and impact or the like. This construction makes it possible to prevent the permeation of water through the ends and enhance the durability of cables.