Abstract: The invention relates to a building panel constructed in layers, including main layer with a mixture of binder and reinforcing additive, and at least one further layer which can be a facing and/or intermediate layer, the further layer including a reinforcement and a binder. The formation of a homogeneous transitional layer betwee the main layer and the further layer insures that the composition of the components of the individual layers changes gradually so as to provide a stable multilayer panel which was improved elastomechanical properties.

Abstract: A process for manufacturing a multilayer building panel in which one layer s a main layer comprising a binder and a reinforcing additive, and another layer contains a binder and a reinforcement such as a mat includes depositing the various layers such that one layer is deposited with an excess of water for hardening, and another with a deficiency, so that the water is caused to migrate between layers and creates a transition layer providing a gradual and continuous transition in composition between the layers.

Abstract: The present invention is directed to a process for the manufacture of plasterboard optionally strengthened with reinforcing materials by mixing gypsum capable of rehydration with water and optionally reinforcing materials and subsequently pressing the resulting mixture, characterized in that polyisocyanates are added to the mixture used for producing the plasterboard and/or are applied to the surface of the finished plasterboard. The invention is also directed to the optionally reinforced plasterboard.

Abstract: The invention provides an installation and method for the continuous production of materials using exothermically hardening binders, such as gypsum or cement, comprising a mixing and feeding station and a calibrating unit or press and also a control system for operating the installation.

Abstract: This invention provides a process of producing a building product, particularly a gypsum slab having preferably a density of below 800 kg/m.sup.3, with gypsum and mixing water. The quantity of mixing water required for rehydration and molding is at least substantially completely introduced into the gypsum by means of water saturated porous particles added in a distributed form. The process comprises the steps of intimately mixing water saturated particles with pulverous gypsum to form a fluid mixture; converting said fluid mixture at least almost completely without the application of pressure to the shape of a gypsum building product; permitting mixing water of the water saturated particles to be absorbed by the pulverous gypsum, and permitting the resulting mixture to set and harden.