PLATE CONNECTION STRUCTURE FOR SANDWICH FLOOR SLAB, FORMATION OF SANDWICH FLOOR SLAB, BOLT AND WASHER SET, AND BOLT AND NUT SET

摘要

PROBLEM TO BE SOLVED: To repair a concrete floor slab for an existing bridge to form a sandwich floor slab. SOLUTION: A first bolt 6 having a large diameter screw (right-hand thread) 19 and a small diameter screw (left-hand thread) and a connecting nut 10 having a left-hand thread 45 at one end side and a right-hand thread 46 at the other end side are prepared. A lock nut 9 is screwed on the large diameter screw 19 and the first bolt 6 is fitted to a lower plate 3. The left-hand thread 45 of the connecting nut 10 is screwed on the small diameter screw 20 and further, the second bolt inserted in the bolt hole of the upper plate is screwed on the right-hand thread 46 and the second bolt 7 is turned to corotate together with the connecting nut 10 to move it up. Then, concrete is placed in a through hole 4.