EP0258734A2 - Layered building panel and method of manufacturing it - Google Patents

Abstract

The building panel (10) consists of at least one edge layer (12) and/or intermediate layer (22) which preferably consists of binder, a reinforcement (20) inserted into this edge layer (12) and/or intermediate layer (22), and at least one main layer (14) which consists of a binder/aggregate and reinforcing material mixture. By forming a homogenous transition layer from the edge/intermediate layer to the main layer, a gradually proceeding transition of the component composition of the individual building panel layers is ensured in order thus to provide a multi-layered panel which is stable per se and possesses, in particular increased elastomechanical properties. <IMAGE>

Description

The present invention relates to a building board in a layered structure with good elastomechanical and fire protection properties, preferably for use as a double or multiple floor in the furnishing of computer rooms, and a method for its production.

The trend towards lightweight construction in the construction industry is being followed by better technical and economic utilization of materials, particularly in composite construction. Their main advantage is that different, otherwise uncoupled material properties can be combined in one component. Appropriate selection of the individual components enables the most favorable properties to be developed for particular areas of use. If, for example, the load-bearing capacity and the fire resistance are taken into account, a combined favorable material property can be achieved by a combination of known purg plasterboards with glass fibers in the form of a mat. Such a combination is carried out in an already known process in that, in the wet process, glass fibers as mats or fabrics are inserted in amounts of up to 10% by mass in Purgips panels, with the poor elastomechanical properties of the Purgipsplatte can be improved by the combination with the glass fibers.

The technical development also went on to multi-layer panels, in which each layer takes on a part of the overall function to be performed by the panel. Technologically, there are three distinct ways of producing such panels:
- Combinations in which the layers are connected to each other by glue;
- Combinations in which the layers are held together by constructive connecting links;
- Combinations in which the layers stick together through the building material's own adhesive forces.

Adhesive connections have disadvantages due to the age-related embrittlement and the requirement for the joint fit, which can have an effect especially on load-bearing components. In the second method, individual prefabricated layers are subsequently screwed together or connected in some other way. In practice, mechanical post-assembly is currently preferred.

From DD-PS 47099 it is known to use the swelling forces acting in the course of hydration in glass fiber reinforced gypsum plaster layers for connection to other materials. The principle is based on the fact that the metal pass is angled in a dovetail shape frame liquid to plastically applied gypsum cover layers form a firm bond with them due to their swelling. Metal and glass fiber reinforced gypsum then interact statically, with the metal frame also taking over the edge protection. If you press support cores, such as honeycomb or lattice structures, so deeply into the binder mixture of the cover layer that plaster can flow around them in the contact zone, a connection is also obtained between these two. In general, a support layer in a binder suspension, which is in the flowable state, is therefore pressed in to the extent that the cured state produces an adhesive strength between the two layers in the hardened state. According to this method, it is also known to apply a layer of gypsum milk and glass fiber to a shaping sheet and then to press a particle board into the still flowable layer of gypsum glass fiber. To improve the adhesion between the plaster and particle board layer, the particle board surface is roughened with coarse sandpaper or grooved to improve the adhesion between the plasterboard layer and the main particle board layer.

Despite this improvement measure, the bond between the gypsum layer and the particle board layer is insufficient, so that the multilayer board tends to lose its adhesion at the interface between the particle board and the gypsum layer. Particularly when a gypsum-glass fiber layer is used as an intermediate layer between two chipboards, there is a risk that the chipboard layers may be due to the low adhesive properties of the gypsum layer no longer adhere to one another under heavy elastomechanical stress.

It is therefore the task of further developing the generic multilayer board in such a way that there is a secure bond between the individual layers and thus a building board with improved combined material properties, in particular improved elastomechanical properties, is made available.

This object is achieved according to the invention by the subject matter of main claim 1.

The building board according to the invention has either an edge layer or an intermediate layer or a combination of edge and intermediate layers made of a binder, which are relatively thin compared to one or more main layers, which are composed of a mixture of binder and additives or reinforcing materials . Reinforcements are introduced in the edge and / or intermediate layers, which are arranged in a preferred embodiment in an area close to the edge and in another preferred embodiment directly in the edge area of the binder edge layer. The basic idea of the invention is that in order to achieve the best possible connection between the individual layers of the building board in the layer structure, the formation of an interface between the individual layers is suppressed in order to form a homogeneous transition layer between the individual boundary, main and intermediate layers.

According to a preferred embodiment, the reinforcement consists of a fiber insert, which in turn can be composed of woven or non-woven glass fiber material.

A conventional inorganic binder, preferably gypsum, or a mixture of binders can serve as the binder of the boundary, intermediate and main layer and a porous inorganic or organic material is added to the main layer as an additive or reinforcement material, which is used to absorb, store and release the Mixing water, which is required to set the binder, is suitable and can also have a reinforcing effect. Water-soaked particles consisting of wood shavings, paper chips, wood or waste paper fibers, wood fiber granules, bark particles or similar organic materials are particularly suitable for this purpose. Particularly good building material properties are achieved with a main layer made from a wood chip binder mixture. Gas aggregate, expanded clay or expanded mica particles, preferably vermiculite, foam or rock glass, preferably perlite, or synthetic resin foam flakes, which can also contain the mixing water required for rehydration and shaping, are also possible as additives or reinforcement materials. Dihydrate grains of about 1 to 5 mm grain size can also be added as crystallization nuclei.

In order to increase the strength properties, according to a preferred embodiment, a binder mixture of sulfate, lime-donating and puzzolani is used as the binder of the surface, intermediate and / or main layer substances, as it is described in DE-OS-3 230 406, used. This binder mixture consists of 50 to 90% by mass calcium sulfate, 3 to 25% by mass lime-donating substances and 5 to 35% by mass highly active alumosilicate, pozzolanic substances rich in aluminum. The strength properties improved by the choice of the binder are due in particular to the fact that the pozzolan component has substantial proportions of active alumina, as is the case with tuffs, many lignite powders, some slag in a smelter, etc. In addition to calcium sulfate dihydrate, another reaction product is formed with the participation of calcium sulfate hemihydrate, namely tricalcium aluminate trisulfate hydrate (ettringite), which makes a decisive contribution to increasing the strength. The entire hardening process of the binder mixture is determined by this reaction. Since the ettringite binds a lot of water of hydration (30 ... 32 moles of H₂O per mole of ettringite), the course of the reaction is generally associated with an increase in volume. This increase in volume correlates with the quantity of the ettringite formed as a function of time. However, the formation of the ettringite in the hardening products can lead to a considerable decrease in strength or even destruction of the structure instead of an increase in strength. An increase in strength is achieved precisely when conditions were present in which ettringite can only arise during the solution phase. According to a further preferred embodiment of the solution, this is achieved in that the binder composition is considered to harden in a stable manner and is therefore suitable if, after a hardening time of 7 days for a prismatic test specimen, a maximum permissible Length change of 0.5% is not exceeded. If this technical rule is not observed, a decrease in strength in the building board can be expected. With constant gypsum supply, the formation of ettringite through the solution phase is related both to calcium hydroxide concentration development and to the increase in volume. In order to increase the certainty that the ettringite formation is limited to the solution phase, the proportion of the pozzolan component can be increased compared to that of the lime component.

However, the teaching according to the invention is not only limited to the use of sulfate binders, but also applies to other inorganic binders, for example cement.

The optimal ratio can be determined by the volume change behavior of reference samples according to the preferred embodiment described above.

In a process for the production of the building board according to the invention in a layered structure, the free-flowing aggregate or reinforcement / binder mixture, the majority of the powdery binder particles already adhering to the moist surfaces of the larger aggregate or reinforcement particles and taking over water, on a base area sprinkled, the reinforcement placed on this layer and the powdered binder layer dusted. The aggregate or reinforcement material of the main layer contains the mixing water required to set all of the existing binder. Then by shaking, wiping, rolling or applying a small Surface pressure ensures that the packing density between aggregate or reinforcement and binder particles is increased so that the mixing water necessary for setting the binder emerges from the aggregate or reinforcement via further contact points between aggregate or reinforcement and binder. is released to the surrounding binder and creates a coherent plaster matrix. The amount of water is sufficient to supply the binding agent of the bordering or intermediate layer with the hydrate water necessary for hardening. By increasing the packing density, supported by the water transport, the boundary layer area between the edge and / or intermediate layers and the main layer, which is essential for achieving the desired composite properties, is formed.

Further advantageous process variants result from the further subclaims. All processes for the production of the plate according to the invention must be carried out using a semi-dry process.

By using the semi-dry process according to the invention for the production of multi-layer boards shown here, the high costs for sealing the molding systems, which occur when using wet technologies, in that part of the excess water escapes from the mixture of substances during component production and contaminates the machines, is saved. A portion of the water used in wet technology is also included many gypsum particles are contaminated wastewater. For the drying of the multi-layer panels produced in wet technology, it is also important that a relatively large amount of free water remaining in the panel has to be removed from the gypsum components, and therefore again high costs have to be incurred, since it is usually here is a thermal drying. The expelled water then leaves a correspondingly large pore space in the hardening product, as a result of which the material density is reduced and the mechanical material properties deteriorate. In the multi-layer building board according to the invention, the use of semi-dry technology takes advantage of the fact that the water retention capacity of porous aggregate - for example expanded clay, perlite, shredded paper and wood chips - is less than the water absorption capacity of the capillary-porous binder of the main, intermediate and outer layers. From the exploitation of this phenomenon according to the invention, it can be seen that the use of the semi-dry process with a water excess which is reduced by 50 to 70% compared to the wet process allows the supply of sufficient amount of water for hydration. A new principle has thus been found on which the inventive production of multi-layer boards with at least one main layer based, for example, on a wood chip-gypsum mixture is based: The wet wood chips act as water deposits, from which the associated gypsum binder removes the setting water required for hydration. The chip-gypsum mixture, which is only earth-moist, is mechanically sprinkled on a base and compacted. Since the bending strength of a gypsum-bonded particle board - apart from the additional reinforcement - with the Correlating density, a higher compression is synonymous with a higher bending strength. In the hardened slab, the chips also act as reinforcement of the gypsum matrix and combine in a boundary layer area between the main layer and the adjacent boundary or intermediate layers with the gypsum of these boundary or intermediate layers, supported particularly intensively by the water transfer.

The corresponding processes can be carried out either batchwise or continuously for the production of the mat-reinforced or fiber-reinforced materials. Suitable methods of depositing the individual layers of the so-called material fleece formation can be both mechanical and pneumatic methods.

The formation of the transition layer, which represents a gradual, continuous transition from the composition of the main layer to the composition of the surface and / or intermediate layer, this transition according to the composition to be referred to as a homogeneous transition, leads to a kind of interlocking of the aggregate or reinforcement material Main layer with the binder of the outer or intermediate layer. As soon as layers are sprinkled onto layers that have already been deposited, aggregates or reinforcement materials penetrate into the binder layer at the interface, which may be supported by the subsequent application of slight surface pressure or by shaking. In addition, a washout effect of reinforcement particles can occur in the lower layers of the main layer Released water from the upper layer areas of the main layer support the formation of the transition layer.

Because several of the methods listed in the subclaims can be combined with one another, physical parameters such as bending strength, modulus of elasticity, bulk density and the like can be set depending on the number and layer thickness of the outer, main and intermediate layers.

The subject matter of the invention advantageously improves the fire protection and elastomechanical properties of inorganically bound materials. Furthermore, through the formation of the surface layer, improvements in the surface quality, such as, for example, minimizing the surface roughness and minimizing the porosity, can be achieved, which lead, for example, to the splash water resistance of the inorganically bound building material panel.

Further details, features and advantages result from the following description of exemplary embodiments shown in the drawings.

• Figur 1 einen schematischen Schnitt durch eine erfindungsgemäße zweischichtige Bauplatte, wobei die Bewehrung in einer randnahen Lage liegt,
• Figur 2 einen schematischen Schnitt durch eine erfindungsgemäße zweischichtige Bauplatte, wobei die Bewehrung in unmittelbarer Randlage angeordnet ist,
• Figur 3 einen schematischen Schnitt durch eine erfindungsgemäße dreischichtige Bauplatte, bei der die Bewehrung in einer Zwischenschicht eingebracht ist,
• Figur 4 eine siebenschichtige erfindungsgemäße Bauplatte und die
• Figuren 5 bis 15 schematische Darstellungen unterschied­licher Fasereinlagen, die als Bewehrungen dienen.

Show it:

• FIG. 1 shows a schematic section through a two-layer building board according to the invention, the reinforcement being in a position close to the edge,
• FIG. 2 shows a schematic section through a two-layer building board according to the invention, the reinforcement being arranged in the immediate edge position,
• FIG. 3 shows a schematic section through a three-layer building board according to the invention, in which the reinforcement is introduced in an intermediate layer,
• Figure 4 is a seven-layer building board according to the invention and the
• Figures 5 to 15 are schematic representations of different fiber inserts, which serve as reinforcements.

The two-layer plate 10 according to the invention shown in FIG. 1 consists of an edge layer 12 and a main layer 14 that are comparatively thin with the total thickness. The edge layer 12 in turn is preferably composed of binder particles 16 in a bonded form, which are shown only occasionally in the present FIG. A surface-sealed glass fiber mat 20 is embedded as reinforcement in the binder layer in such a way that a thin layer consisting only of binder is still present between it and the surface. This location is referred to as a location close to the edge. The boundary layer 12 is adjoined by the main layer 14, which is composed of binder particles 16 and aggregate or reinforcement materials 18, which in turn are shown only in isolated cases. Between the main layer 14 and the edge layer 12, an intermediate layer 24 is formed which, with regard to its composition, is a homogeneous transition layer from the binder / aggregate or Reinforcing material mixture to the, apart from the surface-sealed glass fiber mat, represents only the boundary layer consisting of binder.

Figure 2 shows a section through a two-layer building board according to the invention, similar to the example shown in Figure 1. Here only the reinforcing fiber layer is provided in the immediate edge position, which is necessary, for example, when minimizing the thickness of the edge layer.

In the embodiment shown in FIG. 3, two main layers 14 consisting of the binder / aggregate or reinforcement mixture and an intermediate layer 22 of binder with an inserted glass fiber mat are shown as reinforcement 20.

FIG. 4 shows a combination of the exemplary embodiments shown above, in which a multilayer building board is shown in schematic section, which has two edge layers, two intermediate layers and three main layers. The homogeneous transition region 24 forms at all transitions between the boundary, intermediate and main layers.

FIGS. 5 to 15 show embodiments of the reinforcement introduced into the edge or intermediate layer. 5 shows a knotted synthetic fiber fabric, the stitches having a side dimension of approximately 40 mm, FIG. 6 shows an interwoven surface-sealed glass fiber rug, in which one side is 8 mm long and the other 9 mm long, FIG. 7 shows a knotted synthetic fiber woven fabric in which one side length approx 8 is a surface-sealed glass fiber rug, in which one side length is approx. 10 and the other is 11 mm long, FIG. 9 is a similar glass fiber rug, with a fiber diameter that is comparatively thicker than that in FIG. 8, and FIG. 10 is a synthetic fiber fabric, one side length FIG. 11 is a synthetic fiber fabric, in which one side length is approximately 7 mm and the other is approximately 6 mm, FIG. 12 is a similar synthetic fiber fabric, with a thicker fiber diameter, compared to the one shown in FIG. 11 13 a glass fiber mat with the side lengths 6 mm x 5 mm, FIG. 14 a glass fiber mat with a side length of approx. 2 mm and finally FIG. 15 a glass fiber fleece with randomly arranged glass fibers. In addition to these reinforcement materials listed as examples, other glass fiber products, synthetic fibers, organic fibers and mineral fiber materials are also generally suitable.

The construction board according to the invention is to be explained further on the basis of a few examples in which gypsum is used as binder and wood chips as aggregate or reinforcement:

₀ = 1200 kg/m³, und das Hydratwasser-/Bindemittelverhältnis beträgt w =0,16.In the examples described below, gypsum chipboard is produced as multi-layer panels in a panel format of 660 mm x 560 mm x 38 mm. The aggregate / binder ratio x is x = 0.25, the dry density of the gypsum chipboard body reaches a value of

₀ = 1200 kg / m³, and the hydrate / binder ratio is w = 0.16.

It is of fundamental importance for the problem-free execution of this semi-dry process to provide a homogeneously loosened material fleece from a mixture of aggregates and binders, which must not have any agglomerates and is free-flowing. This is achieved by first adding or soaking the additive or the reinforcing material with the sufficient amount of water and then mixing it in a suitable mixing apparatus with the binder in accordance with the desired ratio. In the present examples, satisfactory results were obtained using a Lödige batch mixer with a ploughshare and cutter head. The next most important process component is the spreading technique for the sprinkling of the additive / binder mixture. A double roller spreading station showed good properties in this regard.

example 1

In a discontinuous process, the wood chip binder mixture prepared as above is sprinkled into a formwork box by means of a double roller spreading station and a prepared fiberglass mat is placed thereon. Then gypsum binder is dusted onto the mat through a sieve and wood chip binder material is sprinkled in again. Finally, a slight surface pressure is exerted on the slab, so that a transition layer with a homogeneous transition of the slab component distribution results, among other things due to the flushing out effect of the water distributing to set the gypsum, which even leads to the chips passing through the reinforcement mat protrude and lead to an additional anchoring of this mat in the transition layer between the edge and the main layer. This effect is more pronounced the larger the mesh size of the mesh reinforcement.

The aggregate or reinforcement material of the main layer was soaked with water that the hydrated water requirement of the gypsum binder layer was also covered, resulting in an overall water / binder ratio of w = 0.35.

In this example, the gypsum binder was mixed with additives in a ratio of x z = 0.00025 (add-b based on gypsum binder), as are common in gypsum technology.

Example 2

A wetted glass fiber mat is placed on the bottom of the formwork. A thin layer of gypsum binder is dusted onto this through a sieve and the wood chip binder mixture of the main layer prepared as above is sprinkled in as a loose material fleece by means of a double roller spreading station. As a result of the existing need for hydrated water, the binder layer extracts the remaining water from the mat reinforcement, the surface water and the wood chip binder fleece the remaining amount of water required for binding, whereby the desired transition layer and the interlocking thus achieved is achieved by the reinforcing wood chips. By applying a slight surface pressure, the deposited nonwoven is inter-compacted and interposed on it a non-woven reinforcement mat is placed on which gypsum binder is dusted. Finally, the plate is finally compacted by applying a surface pressure. The water / binder ratio is again w = 0.35. Since the water, based on the water necessary for the hydration of the binder in the main layer, is added in a slight excess, which is a necessary measure against the development of dust during machine scattering of the additive / binder mixture from a process point of view, the disadvantage that can be associated with This procedural advantage is accompanied by the fact that an excess of water is present in the wood chip binder mixture, can be compensated for by the fact that the excess water serves to bind the binder of the surface layer.

Example 3

A glass fiber mat is placed on the bottom of the formwork, onto which a previously mixed mixture of gypsum binder, water and additive is applied in a flowable consistency and is evenly drawn off to minimize the amount used. A water-binder ratio of w = 0.7 is maintained for this stillage and a ratio of additives of xz = 0.00025 is selected. The wood chip binder mixture is sprinkled loosely on this layer, which contains a water / binder ratio of w = 0.2 and thus hardly any excess water is mixed into the wood chip binder fleece. As a result, the formation of pore space during drying, which could weaken the gypsum matrix, avoided. With this method, water reserves are available in the outer layers, which are released into the main layer, the desired transition layer being formed in turn with this water transfer.

If the final compression pressure is increased in the preceding examples, then plates of higher density can be produced without problems. The increase in the final compression pressure is not to be seen in connection with the transition from the water present in the reinforcement materials to the binder, but is aimed exclusively at a reduction in the free pore space, which leads to an increase in strength. For example, a plate made according to Example 1 with a dry density of 1550 kg / m³ has a bending strength of 18 N / mm².

Claims (14)

1. Building board in layers with at least one edge and / or intermediate layer, which consists of hydrated binder and a reinforcement, which is incorporated in this edge and / or intermediate layer and at least one main layer, which preferably consists of a hydrated binder / aggregate -respectively. Reinforcement mix exists,
characterized by
that between the edge (12) and / or intermediate layers (22), which are composed of a mixture of binder and reinforcement material (16) which changes to the solid state, and the mixture of binder / (16) aggregate or reinforcement material ( 18) existing main layers (14) a boundary layer area (24) is formed, which represents a homogeneous transition area with respect to the layer composition. 2. building board in layer structure according to claim 1,
characterized by
that the reinforcement (20) in the binder edge layer (12) is arranged in an area close to the edge. 3. building board in the layer structure according to claim 1,
characterized by
that the reinforcement (20) is arranged directly in the edge region of the binder edge layer (12). 4. building board in layer structure according to one of claims 1 to 3,
characterized by
that the reinforcement (20) consists of a fiber insert, preferably of woven or non-woven glass fiber material. 5. building board in layer structure according to one of claims 1 to 4,
characterized by
that the binder (16) of the boundary, intermediate and main layer is an inorganic binder, preferably gypsum, and the aggregate or reinforcement material (18) of the main layer is made of a porous inorganic or organic material which is used to absorb, store and release water is suitable and performs a reinforcing function, preferably wood shavings, shredded paper, wood fibers, wood fiber granules or bark particles. 6. building board in layer structure according to claim 5,
characterized by
that the binder (16) of the outer, intermediate and main layer is a binder mixture of sulfatic, lime-donating and pozzolanic substances, it consisting of 50 to 90% by mass of calcium sulfate, 3 up to 25% by mass of lime-donating substances and 5 to 35% by mass of active aluminosilicate, aluminum-rich pozzolana substances. 7. building board in layer structure according to claim 6,
characterized by
that the mixing ratio of calcium sulfate, lime-donating substances and active aluminosilicate, aluminate-rich pozzolanic substances is set in such a way that the formation of ettringite is limited to the solution phase, whereby for a predetermination of the suitable binder mixtures these are considered to be space-hardening if, after a hardening time of 7 days, a maximum permissible length change of a prismatic test specimen of 0.5% is not exceeded and a convergent course of the length change time curve can then be determined. 8. A method for producing a building board in the layer structure according to claim 1, 2, 4, 5, 6 and / or 7,
characterized by
that discontinuously or continuously the aggregate or reinforcement material (18) / binder mixture (16), preferably in a ratio x = 0.05 to 0.5, is deposited on a plate or a conveyor belt by trickle scattering, the aggregate or reinforcement material is soaked with water that a water / binder ratio w = 0.16 to 0.6 results, the reinforcement (20) is placed on this layer, the powdered binder layer (16) is applied is dusted and then by shaking, wiping, rolling or applying a surface pressure below about 1.5 N / mm² the packing density between aggregate or reinforcement (18) and binder particles (16) is increased so that the contact points between aggregates or reinforcement and binder is preferably caused by capillary line that the water from the aggregate or reinforcement (18) passes to the binder (16) of the main layer (14) and the binder (16) of the peripheral layer (12), thereby the boundary layer region is formed and a continuous gypsum matrix is formed by hydration of the binder. 9. A method for producing a building board in the layer structure according to claim 1, 3, 4, 5, 6 and / or 7,
characterized by
that the binder (16) is applied discontinuously or continuously to a plate or a conveyor belt by trickle scattering, the reinforcement (20) is embedded in the dry binder, then the binder (16) / aggregate or reinforcement mixture (18) is sprinkled on , wherein the aggregate or reinforcing material (18) contains the amount of water necessary for setting the binder of the main layer and the peripheral layer, preferably in a water / binder ratio of 0.3 = w = 0.6, and by subsequent shaking, wiping , Rolling or a low surface pressure below about 1.5 N / mm² the packing density between the aggregate or reinforcement material (18) and binder particles (16) is increased so that the contact points between aggregate or reinforcement material and binder is preferably caused by capillary line that the water emerges from the reinforcement material and passes to the binder, whereby the Boundary layer area is formed. 10. A method for producing a building board in the layer structure according to claim 9,
characterized by
that the amount of water introduced via the aggregate or reinforcement material (18) is less than the amount of water required to set the binder (16) of the main layer (14) and the peripheral layer (12) and that that in particular for setting the binder (16) Edge layer (12) necessary amount of water is introduced in that the reinforcement introduced into the dry binder (16) is wetted with at least the amount of water which together with the amount of water contained in the aggregate or reinforcement material (18) is sufficient to set the to cause existing binder (16). 11. A method for producing a building board in the layer structure according to claim 1, 3, 5, 6 and / or 7,
characterized by
that a suspension of binder and water in liquid to pulpy consistency is deposited discontinuously or continuously on a plate or a conveyor belt, reinforcement (20) is applied to the binder suspension and pressed into it, the binder (16) / aggregate or reinforcement mixture (18) is sprinkled on, the aggregate or reinforcement material (18) being bound by as much less water for setting the binder (16) as excess water in the binder suspension and by shaking, wiping, rolling or one Surface pressure below 1.5 N / mm² the water emerges from the aggregates or reinforcement materials (18) and the binder suspension and from the binder passes through, which forms the boundary layer area. 12. A method for producing a building board in a layered structure according to claim 11,
characterized by
that the reinforcement (20) is first placed on the plate or the conveyor belt and then the liquid to pasty binder suspension is applied uniformly to it. 13. A method for producing a building board in a layered structure according to one or more of claims 8 to 12,
characterized by
that two or more of these methods are combined with one another to produce more than two-layer plates (10). 14. A method for producing a building board in a layered structure according to one or more of claims 8 to 13,
characterized by
that the water adjusting means, e.g. B. retarder or accelerator, admixed, the ratio of which to the main binder component (10) is measured with 0.01 to 1.0%.

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