| 摘要 |
PURPOSE:To improve the breaking workability of a concrete structure by a method in which a calcium ion adsorping means is inserted into the part to be broken and then pulled out of concrete after the concrete is set, and then the concrete is broken. CONSTITUTION:Plural calcium adsorption bars 6 as calcium ion adsorping means are inserted into the part 5 to be broken, placed as an extrabanking of concrete 3 above a designed head 4 in an excavated pit 2 drilled underground for constructing an underground structure. The lower ends of the bars 6 are supported at places slightly higher than the head 4, and after the concrete is set, the bars 6 are pulled out. Since, by this, the calcium part is diluted and non-concreting part is formed in the part 5, the power required for the breaking work can be saved. |
