Abstract: A method of simultaneously manufacturing a plurality of concrete beams having upper and lower flange parts which are separated by a web part and which extend over a whole length of the beams. The method includes the steps of providing a first form part constituting a bottom part including a plurality of elongate mutually spaced recesses where the recesses have a shape corresponding to the outer portion of the upper flange part of the beams and providing a plurality of elongate intermediate members having a plurality of projections extending from opposing sides thereof which are placed on the bottom part between the recesses such that the lines of contact between the intermediate members and the bottom part are displaced from the bottoms of the recesses. In this manner, when the concrete is poured into the chamber formed by the intermediate members and the bottom part, flash is not formed on the outer portion of the upper flange part of the beams formed by the first form part.

Abstract: An arrangement for use when casting concrete floors, particularly in locales having pillars, floor drains or the like. The arrangement includes straight concrete beams and sections of ring-like concrete beams which are intended to be incorporated in the resultant floor. The ring sections are arranged to coact in order to completely encircle a free-standing pillar or the like, or to partially encircle a pillar located adjacent a wall. The sections are provided with a lower support flange intended to support the ends of the straight beams. The height of the straight beams is so selected in relation to the height of the ring-like beams that when the straight beams rest on the aforementioned support flange, the upper surfaces of both kinds of beams are located in a common plane, on a level with the resultant floor surface, in order to be able to serve as support paths for concrete smoothing devices. The application also relates to a method for manufacturing beams intended for use with the arrangement.

Abstract: A vacuum treatment unit for removing excess water from newly poured concrete. The unit comprises a vacuum pump connectable to at least two suction mats or the like via separate suction pipes. So that the pump will always obtain sufficient cooling, the suction pipes are readily disconnectably connected to the suction mats and said pipes are connected at their other ends to the vacuum pump via a settable valve device so constructed that at least one of the pipes is always connected to the suction side of the pump.

Abstract: This invention relates to apparatus for vacuum processing concrete for removing surplus water from the concrete by exposing the concrete to vacuum. According to the invention solid particles are prevented from being sucked away from the concrete by applying the vacuum to the concrete surface through a sheet perforated with a great number of holes. The holes are sized to substantially exceed the smallest particles to be prevented from being sucked away by filtering within the concrete.