| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve productivity of a half PC board with a piping hole at a plant, attain high efficiency in construction work by saving labor such as stuffing the piping hole with material at a construction site, and bending-install piping passing through a piping hole without any trouble. SOLUTION: This piping hole forming member is constituted of a tubular body 13 having a minimum internal diameter part 12 at the lower end part, whose internal diameter increases in a flaring manner towards the upper part. The internal diameter of the minimum internal diameter part 12 is set to such a size as to generate no clearance substantially in a space to the outer periphery of piping. This is integrated with a half PC board to form a piping hole, and its removable is not required after manufacture of the half PC board, therefore no clearance occurs between the minimum internal diameter part 12 and the piping. As a result, concrete can be laid without the piping hole being stuffed with material. The upper end has the maximum internal diameter, thus it is possible to bend the piping inside the member 11 for bending-installation of the piping without any trouble.</p> |
