Abstract: With the composite plates for raised floors which are supported at their four corners and consist of a shell with open top and manufactured of tension-resistant material as well as a filling of pressure-resistant material, for instance anhydrite, when the plate is under stress there is a higher deflection at the plate border than in the middle of the plate, which is undesirable. In order to substantially equalize the bearing strength of composite plates of the above structural design in the border and the middle of the plate and to assure such plates against rupture at the border, a reinforcement which is practically plate-high is provided on the side wall of the shell, which is connected with the bottom plate of the shell. In addition or alternatively thereto the density and strength of the filling in the border area of the composite plate could also be increased at least twofold as compared with the rest of the area extending toward the middle of the plate.

Abstract: A shallow pan, preferably of tin-coated sheet steel, serves for the production of a self-supporting composite plate, wherein the pan forms the outside wrapper for a filler with high compression resistance, e.g., anhydrite. The pan contains a plurality of punches which provide anchoring with the filler material. To increase the bearing strength of the composite plate, the pan bottom is made up of four intersecting, shallow, bulged-out zones. These zones engage in the middle on a smooth, plate-like elevation and extend each in turn from deep areas along the intersecting symmetry axes of the pan toward the highest areas at each pan corner. The density of the punches in the pan bottom preferably increases from the inside toward the outside.

Abstract: A self-supporting composite plate for double floors, ceilings or the like, with a pan-shaped outside wrapper member and a hardenable mineral filler, e.g., anhydrite, which can be introduced in liquid state into the pan-shaped wrapper member, and in which are embedded lightweight construction materials. The construction materials are substantially spherical bodies that are retained in a predetermined distribution essentially in the area of the statically neutral zone of the composite plate by a latticed holder that is provided within the wrapper member.