Metallic forming sleeve for openings in reinforced concrete floors, comprises welded plates with reinforcing rings and armour plating

摘要

The sleeve (1) is assembled from flat plates (3) and/or cylinder segment-shaped curved plates (4) each having a two-layer construction with a support layer (10) and wear-resistant cover layer containing a high proportion of hard material. Welds (2) are formed along the length edges of the plates to form a substantially cylinder-shaped hollow body. Tension rings spaced apart in the sleeve length direction are used to reinforce the inside of the sleeve. Rotary parts with half-shells are fitted inside the sleeve and an armour plating is provided around the outside of the sleeve, forming a truncated cone-shaped transition between the metal plates and the round cylinder face (5). The sleeve is drawn through the liquid concrete extruded onto a stationary steel web so slowly that the concrete sets before the end of the sleeve is reached. The concrete feed machine is moved at a constant speed along a rail to one side of the web. A spiral compactor, preferably with an alternating rotation direction, can be extended into the sleeve. A shaker located above the compactor is used to assist the compaction of the concrete.