| 摘要 |
<p>1,205,010. Casting concrete. TREMIX A.B. 1 Aug., 1969 [1 Aug., 1968; 10 Jan., 1969], No. 38757/69. Heading B5A. Apparatus for draining newly cast concrete by vacuum treatment includes a filter member 5, e.g. a metal or textile gauze, contacting the concrete surface and covered by a fluted flexible sheet 7, e.g. a rubber mat, with perforations 10 over which a porous strip 11 and ribbon 12 are placed; the latter has slots 13 to which a suction nozzle is manually and detachably applied. In a modification the strip 11 and ribbon 12 are replaced by a rubber ribbon with longitudinal flutes registering with the holes 10 and with longitudinal slots to which the suction nozzle is applied. In a further modification, a course mesh net is located between the gauze 5 and the upper flexible layer.</p> |
