| 摘要 |
PROBLEM TO BE SOLVED: To make a synthetic resin tube endurable under the internal pressure of filled grout, while having proper flexibility, by providing a soft part and a hard part in the synthetic resin tube which holds a cable for tension internally and is filled with the grout inside. SOLUTION: A soft part 11 and a hard part 12 are provided in a transparent synthetic resin tube 3 for protecting a cable which holds the cable for tension internally and is filled with grout inside. The soft part 11 is constituted of polyvinyl chloride resin containing a plasticizer of 20-40 pts., or 25-35 pts. desirably, to 100 pts. of base resin. Since the whole of the tube is transparent, the situation of filling of the grout can be recognized visually with ease from outside, according to this constitution. Therefore a filling operation can be monitored and impairment of the durability of the cable due to early corrosion thereof can be prevented. |
