| 摘要 |
PURPOSE:To raise the efficiency of removing work of on-site concrete pile by a method in which the head of on-site concrete pile is broken as was expected without affecting the concrete portion to be left behind as a structure by combining a tube filled with a moderate breaking agent with a crack inhibitor. CONSTITUTION:A crack inhibitor 6 having a mesh more than 1.2 times the maximum grain size of coarse aggregate used in concrete is set below the face 5 of concrete to be cut off in an iron bar cage consisting of main and belt-like iron bars, and a tube 8 filled with a moderat breaking agent is set horizontally at a place where the center of the tube 8 is matched with the concrete face 5. Also, one end of the tube 8 is opened on the outside of the concrete pile and a covering material 11 wise lower end coninides with the concrete face 5 to be cut off is provided on the whole surface of the iron bars of the concrete portion to be removed. Afterwards, concrete is placed and hardened, and the moderate breaking agent is packed into the tube 8 and expanded to break the concrete face 5. By this, the crack inhibitor 6 can prevent the development of cracks in the vertical and crosswise directions of the concrete structure 1 due to its adhesion to the concrete. |
