To achieve saving of labor for construction and reduction of cost by decreasing the number of installed sleeves in directly placing a sleeve in a beam concrete to form a beam through hole for electric wiring.
This sleeve A directly placed in the beam concrete is formed by an outer cylinder part 1A and an inner cylinder part 2A which are mutually fitted to each other to freely slide in the axial direction, plate-like separators 1B, 2B for intercepting electromagnetic waves are provided in the interior of the outer cylinder part 1A and the interior of the inner cylinder part 2A, the separator 1B of the outer cylinder part 1A between both separators 1B, 2B is cantilevered on the outer end side of the outer cylinder part 1A, and a gap 3 permitting the cylinder wall of the inner cylinder part 2A to be inserted is formed between the separator 1B and the inner surface of the cylinder wall of the outer cylinder part 1A to construct an expansible concrete placing sleeve with the strong-weak current separator.
FUJINAGA YUTAKA
TOKUTANI NOBORU
SHIGEMORI KENICHI
YOSHIDA FUMITAKA
FUKUI MASAHIRO
IDE YOICHI
KUSAFUKA HIROYUKI
SANKO KIZAI KK
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