METHOD FOR FORMING THROUGH-HOLE

• Main Authors: ASAI HIROSHI, SHINOZAKI HIROO, SANKA TAKASHI, ARIKAWA NAOKI
• Format: Patent
• Language: English
• Published: 05.12.2013
• Subjects: PERFORMING OPERATIONS; SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS, SLAG, OR MIXTURESCONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER; TRANSPORTING; WORKING CEMENT, CLAY, OR STONE

PROBLEM TO BE SOLVED: To provide a method for forming a through-hole, by which the long through-hole can be easily formed in a concrete member.SOLUTION: A method for forming a through-hole includes steps of: inserting a bar-like or cylindrical shape retaining member 13 having an outside diameter smaller than an inside diameter of a flexibly-deformable cylindrical member 12 into the cylindrical member 12; putting the shape retaining member-inserted cylindrical member over supporting bars 3 arranged at predetermined intervals; disposing the cylindrical member put thus at a predetermined position in a form 1; introducing compressed air into the resulting cylindrical member; casting concrete into the form while keeping an air-introduced state so that the shape retaining member is contacted with a lower part of an inner peripheral surface of the cylindrical member by means of buoyancy acting on the cylindrical member from the unhardened concrete and the cylindrical member is held along the shape retaining member; releasing the compressed air in the cylindrical member after the concrete is hardened; making a pressure inside the cylindrical member negative to peel off the cylindrical member from the concrete; pulling out the shape retaining member; and pulling the cylindrical member out of the hardened concrete member together with the shape retaining member or together with a pull-out core material which is inserted after the shape retaining member is pulled out.