DE102021125449A1 - PROCESS FOR THE MANUFACTURE OF A CORE-INSULATED PRECAST CONCRETE PART AND A CORE-INSULATED PRECAST CONCRETE PART - Google Patents

Abstract

The present invention describes a method for producing a core-insulated precast concrete part and a core-insulated precast concrete part. In conventional methods, a layer of insulating material consisting of insulating mats is applied to a layer of concrete that is still liquid. When hardening, the two layers combine to form a raw insulating element, which is placed with the side of the insulating layer on another liquid concrete layer. Additional fasteners are used to create a firm connection between the two concrete layers. Due to the use of insulating mats, however, the process carries the risk of falling below the minimum thickness of the concrete layers on the one hand and of air inclusions on the other. To solve this, a concrete layer is poured in a first formwork, provided with fasteners and partially hardened. A second layer of concrete is placed in a second formwork and then a layer of mineral foam is placed on top of this layer of concrete, which is still liquid. The concrete element produced first is now placed on the mineral foam layer, with the connecting means penetrating the mineral foam layer and connecting with the second concrete layer as it hardens, resulting in a core-insulated precast concrete element.

Description

The present invention relates to a method for producing a core-insulated precast concrete part and a core-insulated precast concrete part.

Such a method for producing a thermally insulated precast concrete part is by the EP 3 812 354 A1 taught. In this process, a mineral-based insulating compound is applied to a layer of concrete that is still liquid. The two layers bond together as a result of the subsequent partial curing. The raw insulation element obtained in this way is placed on a concrete layer that is still liquid and is cast in a separate formwork, which hardens to form a double-wall element when it comes into contact with the raw insulation element.

A thermally insulated precast concrete part produced by such a method is through the EP 3 774 686 A2 taught. This object has two layers of concrete, between which an insulating layer is arranged, which contains fillers and lightweight aggregates.

Traditionally, buildings made of concrete are largely built with so-called in-situ concrete. This means that at the site of the construction site, at the position of the walls, ceilings, etc., a formwork is set up, which is filled with liquid concrete on site (hence the term in-situ concrete). After or during curing, the formwork can be removed or, if necessary, used for the construction of another floor.

In recent years, the use of precast concrete parts has become increasingly important. These are standardized or individual structural elements that are produced in precast concrete plants and then transported to the construction site. There are different variants here. A so-called sandwich wall is a precast concrete part that already consists of a load-bearing structure and an insulating layer and only needs to be erected on the construction site. The outer reinforced concrete façade element is usually between 50 mm and 120 mm thick. The subsequent insulation layer consists primarily of expanded (EPS) or extruded (XPS) polystyrene or mineral wool. The third layer is formed by the base layer, which generally represents the inner wall and typically has a thickness of at least 100 mm. A second variant is the similarly designed, core-insulated double wall. It differs from the sandwich wall in that there is a gap between one of the (load-bearing) concrete layers and the insulation layer. After the semi-finished part has been erected on site, this is filled with in-situ concrete, resulting in a seamless core. This also offers the possibility of reducing the thickness of the load-bearing layer(s) compared to the sandwich wall.

Precast concrete has some significant advantages over buildings traditionally constructed with cast-in-place concrete. The production of the parts takes place in a precast concrete plant, where a constantly high product quality can be achieved through controllable and consistent conditions. The weather factor, which must be taken into account on construction sites under the open sky, since it can have a major influence on both the placement of in-situ concrete and its curing, is thus eliminated. Furthermore, the construction time for erecting buildings can be significantly reduced, since the hardening and hardening of concrete structures is shifted forward in terms of time, to the precast concrete plant. Waiting times of several days, sometimes weeks, until the construction of subsequent structures can begin are no longer necessary when using precast concrete elements.

The production process for the manufacture of core-insulated double walls is usually as follows: A first layer of concrete is poured into the formwork provided. At least one layer of insulating material is then placed on the still fresh concrete. Before or after the insulation material is laid, fasteners that connect the first and second shells together in the finished state, as well as optional spacers, are installed in the liquid concrete. This is followed by the hardening of the concrete, as a result of which an insulating element consisting of concrete, insulating material, connecting means and, if necessary, spacers is obtained. A second layer of concrete is then poured into another formwork. The insulation element, rotated by 180° using a turning system, is inserted into this second, still liquid layer of concrete. Consequently, in this process layer, the insulating material side of the insulating element points in the direction of the second concrete layer. If spacers are present in the insulating element, they are inserted into the second concrete layer in such a way that an air gap remains between the insulating material of the insulating element and the second concrete layer. The core-insulated double wall described above is created by the subsequent hardening of the second concrete layer. The air gap mentioned is filled with in-situ concrete after the core-insulated double wall has been erected on site.

It is also possible to dispense with spacers and place the insulating element with the side of the insulating material directly on the still fresh concrete of the second concrete layer. The distance between between the insulating material and the second layer of concrete is zero, which is why a wall built according to this principle is also generally referred to as a zero wall. The zero wall has not been able to assert itself in practice, since various problems come to light when inserting the insulating element with the insulating material side into the second layer of concrete. These are mainly due to the fact that when using board-shaped insulating materials, a slight height offset of these insulating boards is often unavoidable for production reasons. When inserting the insulating element into the still fresh concrete of the second shell, this means that fresh concrete is displaced in some places, which means that the minimum thickness of the concrete required for static purposes or the required concrete covering are not reached. The necessary over-concreting means that excess concrete has to be removed at great expense, or if the concrete overflows from the formwork, the formwork and the surrounding area become heavily soiled. In other places, however, unwanted air gaps can arise or remain between the insulating material and the secondary shell. These can no longer be filled with concrete afterwards, which means there is an increased risk of corrosion for the fasteners and any reinforcement that may be present. The fatigue strength of the component is thus significantly reduced, particularly in areas of increased humidity or other highly corrosive environments. Furthermore, the function of fasteners is impaired if there is an air gap between the insulating material and the concrete of the second shell.

The one mentioned at the beginning EP 3 812 354 A1 describes a method for producing a precast concrete part, in which concrete is poured into a formwork in a first step. Immediately afterwards, a mineral-based insulating compound with inorganic fillers and lightweight aggregates is poured into the hollow mold on the still liquid concrete. A raw insulation element is obtained by curing over a period of several hours and at elevated temperature. This is placed, with the side of the insulating layer, on a still liquid second layer of concrete in a second hollow formwork. In particular, during the subsequent hardening of the second concrete layer, this connects to the insulating layer, as a result of which a double-layer element is obtained. This end product corresponds to the thermally insulated precast concrete part from the one also mentioned at the beginning EP 3 774 686 A2 . A disadvantage of this method is the high weight of the raw insulation element to be turned by a turning system. The insulating material described also corresponds to an insulating plaster, which is not flowable and requires a long curing time. There is also a risk that parts of the hardened but very fragile insulation layer will be damaged when handling with the turning system.

The object of the present invention is therefore to provide a method for producing a core-insulated precast concrete part which avoids the aforementioned disadvantages, in particular when producing zero walls.

This object is achieved with a method for producing a core-insulated precast concrete part according to claim 1.

According to the invention, the method is characterized by a series of steps to be carried out in this order, some of which are necessary and others of which are optional. The optional steps are subject of the dependent subclaims 2 to 18 and are also marked as optional in the following description.

In a first process step, a first formwork is placed on a formwork surface provided for this purpose in a precast concrete plant. Optionally, a release agent can be applied to the formwork and/or the formwork surface. In this formwork, fasteners and, depending on the requirements of the precast concrete part to be produced, reinforcement, spacers and/or built-in parts are introduced and fastened. The first formwork is then filled with liquid concrete, which is distributed evenly within the formwork. The thickness of this first layer of concrete must be defined in advance and depends on the requirements of the precast concrete element to be produced, in particular on its static load capacity. The concrete can then be compacted for a more uniform structure and a better bond between the concrete and the fasteners, spacers, built-in parts and reinforcement. After the first layer of concrete has hardened to form a first concrete element, the formwork is removed from this.

In a subsequent step, a second formwork is placed on a formwork surface. In a similar way to the first formwork described above, this and/or the formwork surface can be wetted with a release agent. Reinforcement and built-in parts can then also be placed and fixed in the second formwork. The concrete to be poured in in a subsequent step encloses these parts, and the subsequent connection between the concrete and these parts can be further improved by compacting the concrete. Immediately following this step, a mineral foam is then applied to the still liquid concrete of the second concrete layer. The thickness of both the second concrete layer and the mineral foam layer was defined in advance and the height of the formwork set accordingly placed. The first concrete element, produced and hardened as explained in the previous paragraph, is now turned by 180° using a turning system so that the connecting means (and the optional spacers) protruding from the concrete element point downwards. In this orientation, the first concrete element is laid down on the second formwork, with the fasteners (and the spacers) penetrating the mineral foam layer and penetrating into the second concrete layer. In order to correct any irregularities in the second concrete layer caused by this process, which can lead to static weaknesses in the precast concrete element, the second concrete layer can be post-compacted. During the subsequent hardening and hardening of the second concrete layer, this enters into a firm connection with the connecting means that have penetrated. A core-insulated precast concrete part is obtained through the hardening and hardening of the mineral foam layer that takes place at the same time.

In a preferred embodiment of the production process described, a granulate-free dry mixture is used to produce the mineral foam. With such a dry mixture, a homogeneous structure of the mineral foam can be ensured and the risk of components of the dry mixture that are not completely dissolved can be eliminated.

The mineral foam is preferably applied to the still liquid second layer of concrete by means of a foam spreader. This makes it possible to apply the mineral foam with little pressure, which means that irregular loading of the concrete layer can be avoided. Furthermore, the foam spreader is also particularly suitable for the production of large precast concrete parts, since homogeneous application can also be guaranteed over a larger area.

In order to achieve the best possible thermal insulation properties of the core-insulated precast concrete part, the composition of the mineral foam is preferably selected such that the dry bulk density of the mineral foam is between 50 kg/m ³ and 300 kg/m ³ , preferably between 75 kg/m ³ and 200 kg/m ³ , in particular preferably between 80 kg/m ³ and 150 kg/m ³ . The thermal conductivity of the mineral foam layer is adjusted by varying the thickness of the mineral foam layer and the selected dry density so that it is between 0.035 W/mK and 0.08 W/mK.

In a constructional embodiment, the aforementioned foam distributor also includes a buffer unit which has a buffer volume of at least 0.1 m ³ , preferably at least 1 m ³ . The buffer unit enables mineral foam to be discharged continuously from the foam distributor even when a foam generator is not operated continuously. However, the foam generator preferably produces mineral foam continuously. Depending on current requirements, this can either be fed directly to the foam distributor, which applies the mineral foam immediately, or it can be fed to the buffer unit, in which the mineral foam is temporarily stored.

In another preferred embodiment, the foam distributor also includes a pull-off device. After the mineral foam has been applied, this is placed on the second formwork and pulled over the freshly applied mineral foam in order to pull excess mineral foam over the formwork and smooth the surface of the mineral foam layer. When the first concrete element is subsequently placed, a very good connection can be achieved between the mineral foam layer and the first concrete element, while at the same time the risk of unwanted air inclusions is minimized.

The method according to the invention for producing a core-insulated precast concrete part has several important advantages. The liquid and area-wide application of the mineral foam creates a seamless insulation layer within a precast concrete element, which avoids additional thermal bridges. The so-called "wet in wet" processing, i.e. the application of the liquid mineral foam to the liquid second concrete layer, forms an optimal bond between concrete and insulating material. Furthermore, there are no additional hardening times for the mineral foam, since this hardens at the same time as the concrete of the second concrete layer. The structural similarity of mineral foam and concrete increases recyclability, as both materials can be recycled together. Separation is no longer necessary, which saves a lot of time and high costs compared to classic insulation systems with insulation mats. Furthermore, the mineral foam used is a harmless material from a health point of view, since it is free of volatile substances. The production method according to the invention is also so flexible that both zero walls and core-insulated double walls can be produced with it.

A core-insulated precast concrete part is the subject of the independent product claim 19. Advantageous embodiments are described by the dependent claims 20 to 23.

The core-insulated precast concrete element according to the invention consists in its most basic embodiment of two concrete elements representing the outer sides of the precast concrete element, hereinafter referred to as the first concrete element and the second concrete element, one or more connecting means which firmly connect the first concrete element and the second concrete element to one another, and one between The mineral foam layer arranged between the first concrete element and the second concrete element.

Depending on the intended use of the core-insulated precast concrete part, it can be reinforced to improve the static properties. In addition, this can also have built-in parts that were already introduced during the production of the precast concrete part and are accordingly an integral part of the precast concrete part.

As the name suggests, the core-insulated precast concrete part is used, among other things, for thermal insulation of the structure to be erected with it. The mineral foam layer, which is arranged for this purpose between the first concrete element and the second concrete element, has a dry bulk density between 50 kg/m ³ and 300 kg/m ³ , preferably between 75 kg/m ³ and 200 kg/m ³ , in particular preferably between 80 kg/m ³ and 150 kg/m ³ . Depending on the set thickness of the mineral foam layer and the selected dry density described above, the mineral foam layer has a thermal conductivity of between 0.035 W/mK and 0.08 W/mK.

• 1 eine zur Herstellung eines ersten Betonelements erforderliche Vorrichtung,
• 2 eine zur Herstellung eines zweiten Betonelements mit einer darin anschließenden Mineralschaumschicht erforderliche Vorrichtung,
• 3 den Zustand nach Einfüllen einer zweiten Betonschicht in eine zweite Schalung,
• 4 den Zustand nach Ausbringung einer Mineralschaumschicht auf die zweite Betonschicht in der zweiten Schalung,
• 5 eine Prinzipdarstellung vor Auflegen des ersten Betonelements auf die zweite Schalung beziehungsweise die Mineralschaumschicht,
• 6 den Zustand nach Auflegen des ersten Betonelements auf die zweite Schalung beziehungsweise die Mineralschaumschicht, in welcher die zweite Betonschicht und die Mineralschaumschicht aushärten,
• 7 eine zweite Ausführungsform, bei welcher Abstandhalter zur Einstellung des Abstands zwischen dem erstem Betonelement und dem zweitem Betonelement in das erste Betonelement eingebracht wurden,
• 8 eine dritte Ausführungsform, ähnlich der aus 7, wobei der Abstand zwischen erstem Betonelement und zweitem Betonelement durch die Wahl der Abstandhalter so eingestellt wurde, dass zwischen dem ersten Betonelement und der Mineralschaumschicht ein Luftspalt vorliegt.

The method according to the invention is explained in more detail below with reference to the exemplary embodiments illustrated in the drawings. It shows:

• 1 a device required for the production of a first concrete element,
• 2 a device required for the production of a second concrete element with an adjoining mineral foam layer,
• 3 the state after pouring a second layer of concrete into a second formwork,
• 4 the condition after application of a mineral foam layer on the second concrete layer in the second formwork,
• 5 a schematic representation before placing the first concrete element on the second formwork or the mineral foam layer,
• 6 the state after placing the first concrete element on the second formwork or the mineral foam layer, in which the second concrete layer and the mineral foam layer harden,
• 7 a second embodiment, in which spacers for adjusting the distance between the first concrete element and the second concrete element were introduced into the first concrete element,
• 8th a third embodiment, similar to that of FIG 7 , wherein the distance between the first concrete element and the second concrete element was adjusted by the choice of spacers so that there is an air gap between the first concrete element and the mineral foam layer.

In a first method step, a first formwork 2 is placed in a precast concrete plant on a first formwork surface 1 provided for this purpose. The dimensions of this first formwork 2 depend on the size requirements for the precast concrete part to be produced. If it is a standard part whose place of use may not yet have been determined at the time of production, standardized formwork in the dimensions customary in the industry is provided. If, on the other hand, an individualized precast concrete part is to be produced for a use that is usually already fixed at the time of production, the dimensions of the formwork can deviate from those of a standardized formwork.

After the first formwork 2 has been positioned or presented on a first formwork surface 1 in a precast concrete plant, in an optional, subsequent process step, a release agent can be applied to the first formwork surface 1 and all surfaces of the first formwork 2 that are to be used in one or more of the subsequent process steps Concrete can come into contact are applied. The release agent ensures that the hardened or hardened concrete can be detached more easily from the first formwork surface 1 or from the first formwork 2 and breakouts, particularly at the corners and edges of the concrete part to be produced, can be avoided. This increases the product quality, and time-consuming and costly post-processing is saved.

In a subsequent, optional method step, reinforcement is introduced into the first formwork 2 that has been provided or placed. This increases the load-bearing capacity of the precast concrete part produced and, in particular, its tensile strength. The reinforcement is usually made of steel, but it can also consist partially or entirely of glass fibers and/or carbon fibers and/or other materials. The latter have advantages over classic steel reinforcements, especially in the area of corrosion protection. Additionally or alternatively, in this optional method step or several built-in parts are placed in the first formwork that are relevant for the later use of the precast concrete part.

In a subsequent method step, one or more fasteners 3 are introduced into the first formwork 2 that has been provided, or fastened in the first formwork 2 . This or these connecting means 3 serve to produce a stable and permanent connection between a first concrete element 8 described below and a second concrete element 10 also described below in the precast concrete part to be produced. They are rod-shaped and preferably have a low heat transfer coefficient so that they do not act as thermal bridges in the final precast concrete part. A version made of glass fiber reinforced plastic is suitable for this purpose, but other materials and composite materials that meet the criteria mentioned above are also conceivable.

Parallel to or subsequent to the method step described above, one or more spacers 4 can also be introduced into the first formwork 2 or fastened in the first formwork 2 in an optional method step. The purpose of the one or more spacers 4 is described below, in particular in connection with the 7 and 8th , explained in more detail. Like the connecting means or means 3, the spacer or means 4 are preferably rod-shaped. They have a very high load-bearing capacity or compressive strength, since they may have to be able to carry the full weight of the first concrete element 8 at least temporarily.

In a subsequent process step, liquid concrete is poured into the first formwork 2 that has been provided. Due to its low viscosity, the concrete is distributed evenly within the first formwork 2, which is why a first concrete layer 7 of the same thickness is formed over the entire surface of the first formwork 2. This distribution process can also be supported or accelerated manually or automatically. The thickness to be achieved for the first concrete layer 7 was defined in advance, in particular in order not to fall below the minimum thickness required for the intended application in terms of statics. According to the previously defined thickness of the first concrete layer 7, the height of the first formwork 2 was selected in the first method step in such a way that the height of the first formwork 2 is at least as great as the thickness of the first concrete layer 7, preferably slightly exceeding it to maintain a reserve . The liquid concrete of the first concrete layer 7 partially encloses the connecting means 3 and the optionally introduced spacer(s) 4, as well as the optionally introduced reinforcement and the optionally introduced built-in part(s). As in 1 shown, the one or more connecting means and one or more spacers (not shown) protrude essentially perpendicularly upwards, ie counter to the direction of gravity, out of the first concrete layer 7 .

In a subsequent, optional method step, the still liquid concrete of the first concrete layer 7 is compacted. As a result of the compression, any air that is still present can escape from the concrete, which air was trapped when the concrete was poured into the first formwork 2 . This prevents the formation of cavities, which can later pose a static risk for the component to be produced. Furthermore, due to the vibration, the concrete connects reliably and evenly tightly to the first formwork 2 , the connecting means or means 3 , the optional reinforcement, the optional built-in part or parts and the optional spacer or spacers 4 .

In a subsequent process step, the concrete of the first concrete layer 7 hardens to form a first concrete element 8. This state is 1 shown, which includes all the elements mentioned that are not optional. This includes the first formwork surface 1, the first formwork 2, one or more fasteners 3 and the first concrete layer 7 or the first concrete element 8.

After the first concrete layer 7 has hardened and the first concrete element 8 has been formed as a result, the first formwork 2 is removed from the first concrete element 8 in a subsequent method step.

As in 2 shown, in a subsequent process step in a precast concrete plant, a second formwork 6 is placed on a second formwork surface 5, which can be the same as the first formwork surface 1. The process and the selection of the second formwork 6 are similar to the method step described above for presenting the first formwork 2. The second formwork 6 is also subject to the additional requirement that, in a method step described below, the entire weight of the first concrete element 8 may be accommodated to have to wear. Corresponding loads must be taken into account when dimensioning and selecting the material for the second formwork 6 .

In a subsequent, optional step, a release agent on the second formwork surface 5 and all surfaces of the second formwork 6, in one or more of the following Process steps can come into contact with concrete applied. The release agent means that the hardened or hardened concrete can be detached more easily from the second formwork surface 5 or from the second formwork 6 and breakouts, particularly at the corners and edges of the concrete part to be produced, can be avoided. This increases the product quality, and time-consuming and costly post-processing is saved.

In a subsequent, optional method step, reinforcement is introduced into the second formwork 6 that has been provided or placed. This increases the load-bearing capacity of the precast concrete part to be produced and, in particular, its tensile strength. The reinforcement is usually made of steel, but it can also consist partially or entirely of glass fibers and/or carbon fibers and/or other materials. The latter have advantages over classic steel reinforcements, especially in the area of corrosion protection. Additionally or alternatively, in this optional method step, one or more built-in parts can be placed in the first formwork, which is or are relevant for the later use of the precast concrete part.

In a subsequent process step, liquid concrete is poured into the second formwork 6 that has been provided. Due to its low viscosity, the concrete is distributed evenly within the second formwork 6, which is why a second concrete layer 9 of the same thickness is formed over the entire surface of the second formwork 6. This distribution process can also be supported or accelerated manually or automatically. The thickness of the second concrete layer 9 to be achieved was defined in advance, in particular in order not to fall below the minimum thickness required for the intended application in terms of statics. Contrary to the selection of the height of the first formwork 2 for the production of the first concrete element 8, the selection of the height of the second formwork 6 also depends on the previously defined thickness of a mineral foam layer 11 described below. The height of the second formwork 6 consequently corresponds at least to the total the previously defined thicknesses of the second concrete layer 9 and the mineral foam layer 11. The liquid concrete of the second concrete layer 9 encloses the optionally introduced reinforcement and the optionally introduced built-in part(s).

In a subsequent, optional method step, the still liquid concrete of the second concrete layer 9 is compacted. As a result of the compression, any air that is still present can escape from the concrete, which air was trapped when the concrete was poured into the second formwork 6 . This prevents the formation of cavities, which can later pose a static risk for the component to be produced. Furthermore, as a result of the shaking, the concrete connects reliably and evenly tightly to the second formwork 6, the optional reinforcement and the optional built-in part(s).

The status after the completion of the above process step is in 3 shown.

In a method step immediately following the method step mentioned above, a liquid mineral foam is applied to the second concrete layer 9, which is still liquid at this point in time. The upper edge of the second formwork 6 serves as a mark for the maximum fill level of the filled mineral foam. The maximum thickness of the mineral foam layer 11 that is formed in this way consequently corresponds to the height of the second formwork 6 minus the thickness of the second concrete layer 9. Analogously to the thickness of the second concrete layer 9, the thickness of the mineral foam layer 11 is also defined in advance. It primarily depends on the environmental conditions at the later place of use of the precast concrete element. The required thickness of the mineral foam layer 11 also increases with increasing demands on the thermal insulation capacity of the precast concrete part.

In a method step which in turn immediately follows the method step mentioned above, the hardened first concrete element 8 is rotated by 180° about a horizontal axis by means of a turning system. The connecting means 3 firmly connected to the first concrete element 8 and the optional spacer(s) accordingly protrude essentially vertically downwards, i.e. in the direction of gravity, from the first concrete element 8, as shown in FIG 5 shown.

Along with the above-mentioned method step, the turned first concrete element 8 is then placed on the second formwork 6 . In this process step, the connecting means protruding from the first concrete element 8 and the optional spacer(s) penetrate the mineral foam layer 11 and penetrate into the second concrete layer 9, as shown in FIG 6 shown. The distance between the second concrete layer 9 and the first concrete element 8 is defined by the height of the second formwork 6 . At the same time, this also corresponds to the thickness of the mineral foam layer 11.

In a subsequent process step, the mineral foam of the mineral foam layer 11 and the concrete of the second concrete layer 9 harden or the connecting means protruding into the second concrete layer 9 . As a result, the first concrete element 8 and the second concrete element 10 are firmly connected to one another via the connecting means 3 or means. In combination with the mineral foam layer 11 arranged between the first concrete element 8 and the second concrete element 10, a core-insulated precast concrete part is obtained.

In an optional method step, which is arranged between the placing of the first concrete element 8 on the second formwork 6 and the hardening of the second concrete layer 9 and the mineral foam layer 11, the concrete of the second concrete layer 9 is post-compacted. This serves to compensate for any irregularities in the second concrete layer 9 caused by the penetration of the connecting means 3 and the optional spacer(s) 4 and ensures a better connection between the second concrete layer 9 and the connecting means(s) 3.

7 shows an alternative embodiment of a core-insulated precast concrete part to be produced with the resulting different process steps. In this embodiment, the dimensions of the base area of the first concrete element 8 are smaller than the dimensions of the base area of the second concrete layer 9 and the mineral foam layer 11. It is therefore not possible to place the first concrete element 8 on the second formwork 6. Placing the first concrete element 8 directly on the mineral foam layer 11 would result in mineral foam of the mineral foam layer 11 being displaced due to the significantly greater density of the first concrete element 8 compared to the mineral foam layer 11 . As a result, on the one hand displaced mineral foam would spill over the second formwork 6 and potentially cause significant soiling, on the other hand the desired thickness of the mineral foam layer 11 could not be achieved, which would lead to disadvantages in the thermal insulation capacity of the core-insulated precast concrete part to be produced. To circumvent this problem, the in 7 illustrated embodiment, one or more spacers 4 are provided. This or these protrude from the first concrete element 8 in such a way that the length of the part of the spacer 4 protruding from the concrete element 8 corresponds to the thickness of the second concrete layer 9 plus the desired thickness of the mineral foam layer 11 . When the first concrete part 8 is placed on the mineral foam layer 11, the result is that the spacer(s) 4 penetrate the mineral foam layer 11 and the second concrete layer 9, as a result of which the spacer(s) 4 stand up on the second formwork surface 5 and bear the entire weight of the first Wear concrete element 8. A displacement of mineral foam of the mineral foam layer 11 by the first concrete element 8, including the consequences mentioned above, can thus be avoided. When the second concrete layer 9 hardens to form the second concrete element 10, the latter enters into a connection with the connecting means or means 3, as a result of which the distance set by the spacer or spacers 4 between the first concrete element 8 and the second concrete element 10 is fixed.

Another alternative embodiment is 8th shown. This is similar to that shown in FIG 7 described embodiment in that the dimensions of the base of the first concrete element 8 are smaller, ie the dimensions of the base of the second concrete layer 9 and the mineral foam layer 11. In contrast to the embodiment described above 8th no production of a so-called zero wall, but of a semi-finished part. The length of the spacer(s) 4 is chosen so that when the spacer(s) 4 stands up on the second formwork surface 5, an air gap remains between the mineral foam layer 11 and the first concrete element 8. After the mineral foam layer 11 and the second concrete layer 9 have hardened to form the second concrete element 10, the core-insulated precast concrete part produced by such a method can be set up at the site of the construction site. The air gap there is filled with in-situ concrete, which results in a seamless concrete core even when several separately manufactured core-insulated precast concrete parts are lined up.

reference list

1

First button

2

First formwork

3

lanyard

4

spacers

5

Second button

6

Second formwork

7

First layer of concrete

8th

First concrete element

9

Second layer of concrete

10

Second concrete element

11

mineral foam layer

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 3812354 A1 [0002, 0009]
• EP 3774686 A2 [0003, 0009]

Claims (23)

Process for the production of a core-insulated precast concrete element with the process steps in the given order: a. Place a first formwork (2) on a first formwork surface (1), b. Positioning and/or fastening of one or more connecting means (3), c. Filling the first formwork (2) with concrete up to a predetermined height to obtain a first concrete layer (7), the predetermined height of the first concrete layer (7) being less than the height of the connecting means(s) (3), i.e. Hardening of the concrete of the first concrete layer (7) in the first formwork (2) to form a first concrete element (8), e. removing the first formwork (2) from the first concrete element (8), f. placing a second formwork (6) on a second formwork surface (5), G. filling the second formwork (6) with concrete to a predetermined level to obtain a second layer of concrete (9), H. Application of a mineral foam to the still liquid second concrete layer (9) in the second formwork (6) up to a predetermined height to obtain a mineral foam layer (11), i. Placing the first concrete element (8), with the connecting means(s) (3) protruding downwards out of the first concrete part (8), on the mineral foam layer (11) or on the second formwork (6), with the connecting means(s) (3) penetrate the mineral foam layer (11) and penetrate into the second concrete layer (9), j. Curing of the concrete of the second concrete layer (9) and of the mineral foam of the mineral foam layer (11) to form a core-insulated precast concrete part. Process for the production of a core-insulated precast concrete element claim 1 , characterized in that after the first formwork (2) has been placed on the first formwork surface (1), a separating agent is applied to the first formwork (2) and/or the first formwork surface (1). Process for the production of a core-insulated precast concrete element claim 1 or 2 , characterized in that reinforcement and/or one or more built-in parts are placed in the first formwork (2). Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 3 , characterized in that in addition to the / the connecting means / n (3) one or more spacers (4) in the first formwork (2) are placed and / or attached. Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 4 , characterized in that the concrete filled in the first formwork (2) is compacted. Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 5 , characterized in that after the second formwork (6) has been placed on the second formwork surface (5), a separating agent is applied to the second formwork (6) and/or the second formwork surface (5). Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 6 , characterized in that reinforcement and/or built-in parts are placed in the second formwork (6). Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 7 , characterized in that the in the second formwork (6) filled concrete is compacted. Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 8th , characterized in that in addition to the connecting means(s) (3), the spacer(s) (4) protrude downwards from the first concrete layer (7) and when the first concrete element (8) is placed on the mineral foam layer (11), the mineral foam layer (11) penetrate and penetrate into the second concrete layer (9), the spacers (4) standing on the second formwork surface (5) and bearing the weight of the first concrete element (8). Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 9 , characterized in that the concrete of the second concrete layer (9) is post-compacted after the first concrete element (8) has been placed on the mineral foam layer (11) or on the second formwork (6). Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 10 , characterized in that a granulate-free dry mix is used to produce the mineral foam. Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 11 , characterized in that the mineral foam is applied to the liquid second concrete layer (9) by a foam spreader. Process for the production of a core-insulated precast concrete element according to one of claims che 1 until 12 , characterized in that the composition of the mineral foam is adjusted in such a way that the hardened mineral foam layer (11) has a dry bulk density of at least 50 kg/m ³ , preferably at least 75 kg/m ³ , particularly preferably at least 80 kg/m ³ . Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 13 , characterized in that the composition of the mineral foam is adjusted in such a way that the hardened mineral foam layer (11) has a dry bulk density of at most 300 kg/m ³ , preferably at most 200 kg/m ³ , particularly preferably at most 150 kg/m ³ . Process for the production of a core-insulated precast concrete element according to one of Claims 1 until 14 , characterized in that the composition of the mineral foam is adjusted in such a way that the thermal conductivity of the mineral foam layer (11) is at least 0.035 W/mK and at most 0.08 W/mK. Process for the production of a core-insulated precast concrete element according to one of Claims 12 until 15 , characterized in that the foam distributor has a buffer unit which has a buffer volume of at least 0.1 m ³ , preferably at least 1 m ³ . Process for the production of a core-insulated precast concrete element Claim 16 , characterized in that a foam generator continuously produces mineral foam, which is either discharged directly via the foam distributor or is temporarily stored in the buffer unit. Process for the production of a core-insulated precast concrete element according to one of Claims 12 until 17 , characterized in that the foam distributor comprises a squeegee which rests on the second formwork (6) and is pulled over the freshly applied mineral foam, thereby pulling excess mineral foam over the second formwork (6), with the surface of the mineral foam layer (11) being smoothed becomes. Core-insulated precast concrete part with a first concrete element (8), a second concrete element (10), connecting means (3) for connecting the first concrete element (8) to the second concrete element (10) and between the first concrete element (8) and the second concrete element ( 10) arranged mineral foam layer (11). Core-insulated precast concrete element claim 19 , which additionally has a reinforcement and/or one or more built-in parts. Core-insulated precast concrete element claim 19 or 20 , whose mineral foam layer (11) has a dry bulk density of at least 50 kg/m ³ , preferably at least 75 kg/m ³ , particularly preferably at least 80 kg/m ³ . Core-insulated precast concrete part according to one of claims 19 until 21 , whose mineral foam layer (11) has a dry bulk density of at most 300 kg/m ³ , preferably at most 200 kg/m ³ , particularly preferably at most 150 kg/m ³ . Core-insulated precast concrete part according to one of claims 19 until 22 , wherein the thermal conductivity of the mineral foam layer (11) is at least 0.035 W/mK and at most 0.08 W/mK.

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