MANUFACTURING METHOD OF PRECAST CONCRETE MEMBER AND PRECAST CONCRETE MEMBER

PROBLEM TO BE SOLVED: To provide a technic capable of easily forming irregularities in a through hole of a PCa member without a sheath tube.SOLUTION: The process of manufacturing method of the present invention is; a single pipe 400 is covered with a vinyl hose 402 (A), a rubber string 404 is spirally wound around the circumference (B), so that a jig 600 for construction of PCa member is made (C). The manufactured jig 600 is fixed at a position where the through hole is to be formed in the formwork and concrete is cast. After obtaining the predetermined strength, the jig 600 is removed in the order of the single pipe 400, the vinyl hose 402, and the rubber string 404. The trace obtained by removing the jig 600 is a through hole with state in which a spiral concave extending on the inner surface for the main reinforcement is formed. As a result, it is possible to form through holes for main reinforcements in the PCa member without sheath tubes, and to provide easily irregularities on the inner surfaces of the through holes.SELECTED DRAWING: Figure 5 【課題】ＰＣａ部材にシース管レスで容易に貫通孔内に凹凸を設けることができる技術を提供する。【解決手段】単管パイプ４００にビニールホース４０２を被せ（Ａ）、周囲にゴムひも４０４を螺旋状に巻き付け（Ｂ）、ＰＣａ部材施工用の治具６００とする（Ｃ）。製作した治具６００を型枠内の貫通孔を形成する予定の位置に固定し、コンクリートを打設する。所定の強度を発現後、単管パイプ４００、ビニールホース４０２、ゴムひも４０４の順に治具６００を除去する。治具６００を除去した跡は主筋の貫通孔となり、その：内面には螺旋状に延びた凹部が形成された状態となる。これにより、ＰＣａ部材にシース管レスで主筋貫通孔を形成し、かつ、貫通孔の内面に容易に凹凸を設けることができる。【選択図】図５