| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensively and easily manufacturable block for a manhole having a superior corrosion resistant structure, the manhole using this block, and a manufacturing method of the block for the manhole. SOLUTION: This block for the manhole includes a base body part 11, a corrosion resistant part 12 and a plurality of projection parts 13. The base body part 11 is mainly composed of a concrete material, and has a through-hole. The corrosion resistant part 12 is mainly composed of a synthetic resin material, and has a through-hole 120, and its outer peripheral surface 121 is provided in close contact on an inner peripheral surface 112 of the through-hole of the base body part 11. The plurality of projection parts 13 are provided in a dotted shape on a contact surface between the base body part 11 and the corrosion resistant part 12. The block 10 for the manhole constitutes the manhole by combining a plurality. The plurality of blocks 10 for the manhole are stacked in the axial direction a1. COPYRIGHT: (C)2007,JPO&INPIT
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