| 摘要 |
PROBLEM TO BE SOLVED: To enable cleansing processing of placed concrete in an initial stage of hardening of the same. SOLUTION: There is provided a water leading apparatus having an expandable water conduit 22, a hydraulic jack 24, and a raw water conveying portion 26. The water conduit 22 is a double pipe consisting of an inner pipe 22a and an outer pipe 22b, and both the edges thereof are opened. The raw water conveying portion 26 has a casing 26a, a filter layer 26b, and an impervious sheet 26c which is hot-water soluble. The casing 26a is of a box shape, and has an open end thereof, which is arranged so as to face an excavated wall surface on the side of natural ground A. The casing is provided with a permeable plate which defines a passage space above the bottom thereof. The filter layer 26b is housed in the easing 26a in a manner being mounted on the permeable plate. Connected to the passage space are ends of three, i.e., first to third feed pipes 26f, 26g, 26h in a manner communicating with the passage space. The three pipes feed cleansing fluid into the passage space, after dissolution of the impervious sheet 26c.
|
