PERMANENT FORMWORK VOID FORMER FOR REINFORCED CONCRETE VOIDED SLABS

摘要

A permanent formwork void former for reinforced concrete voided slabs. The aim of the present invention is to provide slabs with a predetermined strength and to increase the strength of slabs across a wide range of manufacturable sizes by increasing the accuracy with which void formers arranged in a set manner in a reinforced concrete voided slab retain a set optimal shape. The invention relates to building and can be used as a permanent formwork void former in the manufacture of reinforced concrete voided slabs. The permanent formwork void former comprises a hollow body provided with a means for securing same in a spatial position and including conical supporting feet arranged on its outside surface and at least one box-like member in the shape of a truncated pyramid, which is open at the large base end and has channels at the corners formed by the mating of the lateral sides and also has stiffening ribs for reinforcing the top side, said void former being characterized in that the supporting feet are provided with fastening elements in the form of roughness or ribbing on their outside surface or in the form of an anchoring fastener, and the spatial position fixing means is in the form of cylindrical depressions in the outer surface of the upper side of the box-like member with projections for connecting adjacent elements of the permanent formwork to one another with the aid of connection couplings made in form of semi-circular chute at ends, in the form of a chute with U-shaped or triangular cross-section in a middle area and having grooves and holes for connection with appropriate ledges arranged in box part recesses, wherein the interface zone of the box-like member upper side and lateral sides is made bevelled at angle ranging from 20 to 60, and the interface zone height is not less than 1 cm, and the upper side of the box-like member outer surface has roughness in the form of strips, grooves or dots, which height and width does not exceed 10 mm, arranged so that there are gaps, corresponding to stiffness ribs arranged on the inner surface of the box-like member upper side.