EP2755806A1

EP2755806A1 - Method and device for producing a concrete component, and concrete component produced according to the method

Info

Publication number: EP2755806A1
Application number: EP12756071.2A
Authority: EP
Inventors: Asko FROMM
Original assignee: Universitaet Kassel
Current assignee: Universitaet Kassel
Priority date: 2011-09-14
Filing date: 2012-07-04
Publication date: 2014-07-23
Anticipated expiration: 2032-07-04
Also published as: EP2755806B1; US9676119B2; ES2649395T3; US20140284830A1; DE102011113163A1; PL2755806T3; WO2013037338A1

Abstract

The subject matter of the invention is a method for producing a concrete component (1), wherein a plurality of layers of a dry mixture consisting of at least one silicate former and one hydraulic binder are deposited one atop another on a base (7), wherein after applying each layer the respective layer is mixed with water, wherein the contour of the area that is mixed with water correlates with the desired shape of the concrete component (1) at the level of the respective layer to be applied.

Description

METHOD AND DEVICE FOR PREPARING A CONCRETE COMPONENT, AND A METHOD OF PROCESSING

CONCRETE COMPONENT MANUFACTURED

The invention relates to a method and a device for producing a concrete component on the one hand and on the other hand, a concrete component produced by the method.

Concrete components are known in a variety of shapes and sizes. In the past, concrete was mainly used only in the construction of buildings, in particular buildings or bridges. Over time, however, the scope of concrete has certainly expanded. It is already known to produce machine beds from concrete. Such machine beds, for example, are no longer produced from a conventional concrete, as found in the construction industry, in particular in the past, but from special concrete, and in particular UHPC concrete mixtures. Such ultra-high-strength concretes are characterized, inter alia, by the fact that the components produced hereby have substantially smaller dimensions while achieving the same strength values as conventional concretes. This opens up the possibility of such concretes, as already stated not only to use for the construction of buildings, but for components that are highly complex in structure. Now it is known that concrete is poured into molds for shaping. However, such forms have the disadvantage that, depending on the complexity of the component to be cast, the molds become enormously expensive. This is because, much as in plastic injection molding, it is then necessary to provide molds with slides. The production of special molds for corresponding components requires, however, that due to the considerable mold costs with the known form, a considerable number of parts is made, since otherwise such a form is not amortized.

The object underlying the invention is therefore to provide a method for the production of concrete components, and in particular of structured concrete components with recesses and undercuts, which is inexpensive, and therefore also allows the production of small batches cost-covering, and beyond the production of concrete components higher Accuracy allows.

To achieve the object, the invention proposes that several layers of a dry mixture of at least one silicate former and a hydraulic binder are deposited on top of each other, wherein after application of each layer, this respective layer is mixed with water, wherein the contour of the surface, which is mixed with water, correlated with the desired shape of the concrete component in the amount of each layer applied. From this it becomes clear that the principle is that in the

inventive method is a so-called 3D printing. That is, the desired shape of the concrete component is in their

Digitized dimensions entered a corresponding printer, which then makes the creation of the corresponding component in layers, by first the dry mixture is applied in layers, and then the wetting of the individual layers is done with water. Furthermore, it is provided in this connection that the individual layers are applied to one another at specific time intervals, wherein the time interval depends on the progress of the setting process of the respective lower layer. From this it is clear that the prerequisite for the application of a further layer is that the lower layer has at least partially set. This is often the case even when the lower layer is wetted with water in the designated places. That is, the next mixture layer is applied with water immediately after the wetting of the previous layer. A certain setting is therefore

ensure that when applying the further layer, the lower layer remains in its contour and not due to the

Dead weight of the layer or layers above it deviates from the predetermined contour, that is prevents the lower layer is running. On the other hand, it must be ensured that the layers still have a moisture that allows a material connection between the individual layers, so that a homogeneous component is formed. Specifically, it has been found that if the layer has a thickness of 0.05 to 5 mm, and preferably 0.1 mm, a relatively short time is needed for the setting process after spraying with water, so that after completion of the spraying process immediately at the other end of the layer, the next layer can be applied. Ie. It is a substantially continuous production possible.

With the method according to the invention concrete components can be produced, which were previously not or only with considerable difficulty and at considerable cost to produce. In particular, with the Process concrete components produced, the undercuts have or also show recesses which extend in several directions in space.

The invention also relates to a device for the production

5 of a concrete component, which consists of several superimposed

Layers of a dry mixture and at least one

Silicate and a hydraulic binder is constructed, wherein the topmost layer is mixed with water. From 3D printing technology is known to produce three-dimensional objects (DE 10 2008 059 i o 600 A1). As printing material find such based on epoxy resin and polyamide use. When using epoxy resin and polyamide, in principle, there are no restrictions on the use of the heads for discharging the corresponding material. Epoxy resin and polyamide are in liquid or pasty state by nozzles

15 can be sprayed, which are so fine that a contour-sharp contouring of the component is possible. However, the subject matter of the invention is not the production of components made of such epoxy resins or polyamides but rather the production of complex, structured components made of concrete. For the production of concrete at least one silicate former is used,

20 and a hydraulic binder, in particular Portland cement. The mixture of a silicate-forming agent and, for example, a sand and also a cement is not suitable for the production of a contour-sharp structured without the use of molds

Concrete component. As a result, now that the last layer or even the

25 top layer of the dry mixture of silicate and

hydraulic binder is wetted with water, it is now possible to provide over the contour-sharp wetting of the layer with water and a corresponding contour sharp component. In this respect, it is provided for the device for producing the concrete component that the

30 device comprises two discharge heads, which are arranged in each case movable in at least one spatial direction on a frame, wherein the one Discharge head discharging the dry mixture of at least one silicate and a hydraulic binder and the other

Discharge head is used to discharge from the water. Here, the discharge head for the dry mixture in at least one spatial direction is movable.

5 In particular for the discharge head for the water is an at least

two-dimensional mobility preferably provided a three-dimensional mobility of the head, since as already stated by the discharge head for the water, which is designed in particular as a spray head, finally the contouring of the individual layers and thus i o also the contouring of the layered concrete component

should be done. That is, the spray head is formed in the manner of a print head.

According to a further feature of the invention it is provided that the

15 discharge head is designed as a discharge chute, wherein the discharge chute has a slot-like discharge opening. In this respect, the following results

Procedure for the production of a contoured concrete component with undercuts and / or cavities. First, the discharge head designed as a discharge channel with a uniform speed over a

20 Move the document. Through the slit-like opening of the discharge chute, the dry mixture of hydraulic binder and silicate former is removed as a layer on the substrate. Immediately afterwards, the layer is sprayed with water. Sprinkle the layer with water through the appropriately as a spray head or printhead

25 trained discharge takes place according to the contour of the

desired components. This means that by applying several layers one above the other on the surface, a e.g. cuboid body arises. Both for the discharge of the dry mixture and for the Wasse raustrag, the discharge heads are advantageous also vertically

30 movable. Alternatively conceivable, however, is also the pad on which the cuboid is built to lower accordingly. In the cuboid is the desired structural component. Since the wetting with water only took place in the areas that ultimately form the structured concrete component, the remaining areas are not included

5 moistened with water. This means that there was no bonding to the concrete there. When the actual component is removed from the cuboid, a powder or granular residue remains on the mixture which has not set, solely due to the fact that certain surfaces of the layers have not come into contact with water. Cavities in the structured concrete component must be blown out or sucked out in order to expose the cavities, with undercuts the mixture trickles off.

It has already been stated elsewhere that the layered

15 construction of such a structured concrete component can essentially only be done in such a way that the respective last layer after the

Sprinkle with water as long as no further layer is applied until this layer has set to a certain extent. At low

Layer densities, this is relatively fast, so that a

20 continuous application and wetting is possible. Would the

layered build-up too fast, d. H. without that

Wait for the setting of the individual layers, then would

Eventually the whole body will diverge at a certain load of the lower layers.

25

The invention also relates to a concrete component which has been produced by the method described above. Such a concrete component is characterized by one or more recesses z. B. tubular cavities, wherein in the one or more recesses a

30 liquid or pasty curable composition can be introduced. The crowd can be made of plastic or made of liquid metal.

Although it is known that concrete components are able to withstand a high degree of pressure forces, they can not withstand tensile forces or withstand only a small amount. To be able to transfer tensile forces with a concrete component is therefore always the use of

Reinforcements required. The best known here are the so-called structural steels, which increase the friction in the concrete component on their

Have top circumferential ribs. Especially in strong

Contoured and structured concrete components, as they are the subject of the present invention, the introduction of reinforcements is hardly or not possible. As a result, however, that such structured components can be produced, it is also possible to provide in the concrete component in the production recesses whose geometry optimally adapts to the force flow of attacking forces that can not be taken or not to a significant extent of the concrete itself. After completion of the concrete component, the recesses are poured out with a liquid or pasty hardenable mass, as already mentioned. Such plastics or metals, in the corresponding recesses in the

Cast concrete component can serve insofar as reinforcement. It immediately becomes clear that at one after the

According to the invention manufactured component not only compressive forces are transferable, but also tensile forces, if it is assumed that the recesses in the concrete component of the inclusion of materials are used, which are able to transmit tensile forces, like this

For example, in the corresponding plastics and metals is the case. This results in a composite component whose carrying capacity can be greater than that of the individual component. After a special feature is in this context

provided that the mass in the cured state on the

Recess protrudes so as to serve directly the connection with, for example, another concrete component.

With reference to the drawings, the invention will be explained in more detail below by way of example.

Fig. 1 shows schematically a Betonbauteii the invention

Art;

Fig. 2 shows a view from above of the concrete part of FIG. 1;

Fig. 2 a shows an embodiment of the cavity in a view of the

Concrete part according to the line IIa / IIa of Fig. 1;

Fig. 3 shows a device for producing a concrete component in a schematic representation;

Fig. 4 shows a side view of Fig. 3;

As shown in FIG. 1, the concrete component is designated 1. The concrete component 1 shows three superimposed recesses 2, which serve to receive a reinforcement. The one recess is intended to extend in three spatial directions in order to make it clear which possibilities the method according to the invention opens up.

From Fig. 2 and Fig. 2a, the structure in the region of the upper and middle recess 2, which extends obliquely in the concrete component. Visible, the individual layers 5 of the concrete component in the region of the recess 2 are formed in a stepwise outward running manner then, after reaching the lateral apex of the approximately circular recess to converge upward again. The production of the recess 2 is carried out in detail by the fact that, as already stated, the individual layers of the dry mixture are deposited on each other. The layers are wetted with water only where the layer is to set to form the concrete component. In this respect, layers of dry mixture are also located in the cavity to be formed, wherein the layers are supported above the horizontal vertex of a substantially circular recess on the underlying layers which have not been sprayed with water. The dry, not hardened mixture contained in the recess trickles out on receiving the concrete part of the pad from the recess or it we blown out. The device according to FIG. 3 is characterized by one in three

Spatial directions movable discharge head 10, which is designed as a discharge channel and which is arranged on a cross member 21. The traverse 21 is held by two supports 22 which are displaceable on rails 23 in the direction of the arrow 25. The traverse 21 is held vertically movable by the supports 22 (arrow 35). The traverse 21 forms with the rails 23 and the supports 22, the frame 20. At the discharge head 10 is designed as a spray head further discharge head 27, which serves for the discharge of water. The discharge tray 27 movably arranged by the traverse in the direction of the arrow 30 and the discharge head 27 attached to the discharge chute and designed as a spray head are thus movable in three spatial directions.

Trained as a discharge chute 10 has on the bottom of a slot-like discharge opening 1 1 for the mixture of hydraulic Binders and silicate formers z. Sand on. The spray head is used for contour-sharp spraying of water.

The procedure for producing a structured concrete part is as follows: First, a layer of the mixture of hydraulic binder and silicate is applied to the substrate 7 through the discharge head 10 designed as a discharge channel. The layer is in plan view z. B. rectangular. Then the layer becomes

sprayed with water according to the desired contour. After the layer has set or at least partially set so that it is stiff, in turn, a layer of the dry mixture is applied in a rectangular shape to this first layer. Then this layer is sprayed with water according to the desired contour of this layer. The whole process is continued in layers until the body is finished as a concrete part. Then the concrete part is lifted off the base. The unbound mixture dissolves from the concrete part or concrete body; Cavities in the concrete part can be excluded with compressed air.

In the cavities 2, a hardenable mass can be introduced, which is able to absorb tensile forces after curing. When

Hardening of mass comes here z. B. a plastic z. As a resin in question.

Claims

Claims:

1. Method for producing a concrete component,

characterized,

that on a substrate (7) several layers (5) of a dry mixture of at least one silicate and a

hydraulic binder are deposited on top of each other, wherein after application of each layer (5) the respective layer (5) is mixed with water, wherein the contour of the surface, which is mixed with water with the desired shape of the concrete component in the amount of each layer to be applied (5) correlates.

2. The method according to claim 1,

characterized,

the individual layers (5) are applied to one another at specific time intervals, the time intervals being dependent on the progress of the setting process of the respective lower layer.

3. The method according to claim 1 or 2,

characterized,

the layers (5) have a thickness of 0.05 to 5 mm, preferably 0.1 mm.

4. Apparatus for producing a concrete component, which consists of a plurality of superimposed layers (5) of a dry mixture of at least one silicate former and a hydraulic

Binder is formed, wherein the topmost layer is mixed with water,

characterized, in that the device comprises two discharge heads (10, 27) which are each arranged to be movable in a frame (20) in at least one spatial direction, the one discharge head (10) serving to discharge the dry mixture of at least one silicate former and a hydraulic binder, and the other discharge head (27) serves to discharge from the water.

5. Apparatus according to claim 4,

characterized,

in that the discharge head (27) for the water is movably mounted in the frame (20) at least in two, preferably in three spatial directions.

6. Apparatus according to claim 4 or 5

characterized,

in that the discharge head (27) for the water is designed as a spray head.

7. Apparatus according to claim 4,

characterized,

in that the discharge head (10) for the mixture is designed as a discharge chute, the discharge head having a slot-like discharge opening (11).

8. concrete component produced by the method according to one of

Claims 1 to 3,

characterized,

that the concrete component has one or more recesses (2), wherein in the one or more recesses (2) a liquid or pasty, hardenable mass can be introduced.

9. concrete component according to claim 8,

characterized,

that the mass is a plastic or a metal.

10. Concrete component according to claim 8 or 9,

characterized,

that the mass in the cured state over the recess (2) protrudes.