EP3663474A1 - Device for decoupling heat between a concrete wall of a building and a floor and production method - Google Patents

Abstract

A thermal insulation element for heat decoupling between structural parts of the building to be made of concrete, namely a vertical building wall and a floor or ceiling above or below, is specified, the thermal insulation element having a basic body to be laid linearly between the building parts and which is at least partially made of a pressure-transmitting and heat-insulating material, namely lightweight concrete, and has an upper and a lower contact surface for vertical connection to the building parts. The thermal insulation element has on its upper and lower contact surface in each case a plurality of projections which run at least partially perpendicular to the laying direction.

Description

The present invention relates to a thermal insulation element for heat decoupling between load-bearing building parts to be made of concrete, namely a vertical building wall and a floor or ceiling above or below, the thermal insulation element having a basic body to be laid linearly between the building parts, which at least partially consists of a pressure-transmitting and heat-insulating Material, namely lightweight concrete, and has an upper and a lower contact surface for vertical connection to the building parts.

In building construction, load-bearing parts of buildings are often created from reinforced concrete structures. For energy reasons, such parts of the building are usually provided with external thermal insulation. In particular, the floor ceiling between the basement, such as a basement or underground garage, and the ground floor is often equipped with thermal insulation on the basement side. The difficulty arises here that the load-bearing parts of the building on which the building rests, such as columns and outer walls, have to be connected in a load-bearing manner to the parts of the building above, in particular the floor ceiling. This is usually achieved by monolithically connecting the floor slab to the load-bearing columns and external walls with continuous reinforcement. However, this creates thermal bridges that are difficult to remove by means of thermal insulation that has been attached from the outside.

In Scripture EP 3 112 542 A1 describes a thermal insulation element with a base made of lightweight concrete and reinforcing bars made of a fiber composite material and penetrating these. The thermal insulation element shown there is used for heat decoupling between a column and a floor slab, but is less suitable for load-bearing building walls.

From Scripture DE 101 06 222 describes a brick-shaped wall element for heat decoupling between wall parts and floor or ceiling parts. The thermal insulation element has a pressure-resistant support structure with insulating elements arranged in the spaces. The supporting structure can consist of a lightweight concrete, for example. Such a thermal insulation element is used for thermal insulation of brick outer walls, for example, as a conventional brick, it is used as the first stone layer of the load-bearing outer wall above the basement ceiling.

From Scripture EP 2 405 065 a pressure-transmitting and insulating connecting element is known, which is used for the vertical, load-bearing connection of building parts to be made of concrete. It consists of an insulation body with one or more pressure elements embedded in it. Shear force reinforcement elements run through the pressure elements and, for connection to the parts of the building to be made of concrete, extend essentially vertically beyond the top and the bottom of the insulation body. The insulation body can for example be made of foam glass or expanded polystyrene rigid foam and the pressure elements made of concrete, fiber concrete or fiber plastic.

Vertical heat decoupling is achieved here by reducing the contact area between the parts of the building. Due to the heat decoupling, large temperature jumps occur between the parts of the building. In the case of large building parts such as a building wall and a floor ceiling, the resulting different thermal expansion can lead to tensions and relative movements between the building parts, which can lead to static problems due to the reduced support points.

It is therefore an object of the invention to provide a thermal insulation element which is more suitable for use for heat decoupling between a building wall and a floor or ceiling above or below.

The object is achieved by the features of claim 1. Advantageous refinements can be found in the dependent claims.

In the case of a thermal insulation element of the type mentioned at the outset, it is provided according to the invention that the thermal insulation element in each case has a plurality of protrusions on its upper and lower contact surface, at least — viewed in plan view of the contact surface — partially perpendicular to the laying direction.

The invention is based on the basic idea of a linear laying of the thermal insulation elements in the composite, i.e. The thermal insulation elements are laid with their short end faces butt-to-butt without leaving a space between them. The power transmission between the building wall and the floor ceiling is therefore distributed linearly over the entire length of the building wall instead of on individual support points. The base body of the thermal insulation elements is preferably essentially cuboid, with its longitudinal axis specifying the direction of installation.

According to investigations by the inventors, due to the temperature-related different thermal expansion of the adjacent parts of the building, force components directed along the building wall occur which have to be compensated for by opposing forces at the transition to the floor ceiling. These forces cause a certain torque on the thermal insulation elements, which is absorbed during the abovementioned joint-to-joint installation via the adjacent thermal insulation elements. The projections according to the invention on the connection surfaces of the thermal insulation elements bring about a toothing between the thermal insulation elements and the adjacent building parts transversely to the direction of force, by means of which an effective introduction of the laterally directed force components into the adjacent building parts is ensured.

According to the invention, the thermal insulation element consists at least partially of lightweight concrete as a pressure-transmitting and heat-insulating material. Under lightweight concrete, according to the applicable regulations, there is a concrete with a dry bulk density of a maximum of 2000 kg / m ³ - typically about 1600 kg / m ³ - defined. The low density compared to normal concrete is achieved by appropriate manufacturing processes and different lightweight concrete grains, preferably grains with grain porosity such as expanded clay. In the dry state, lightweight concrete in the composition used here has a thermal conductivity between approximately 0.4 and 0.6 W / (m · K). The thermal conductivity λ _{10, tr} is usually measured at a mean temperature of 10 ° and after drying to constant weight.

High-pressure-resistant molded elements with low specific thermal conductivity can be made from lightweight concrete. Depending on the structural requirements, such a lightweight concrete part can additionally include hollow chambers or enclosed, non-load-bearing insulating bodies. The height of the thermal insulation element preferably corresponds approximately to the thickness of a typical thermal insulation layer, that is to say approximately 5 to 20 cm, preferably 10 to 15 cm.

By using a solid or hollow block construction made of lightweight concrete, a much larger contact surface is available with the same or less heat loss than would be the case when using high-pressure-resistant pressure elements. Additional pressure-transmitting elements such as thrust bearings or pressure bodies made of high-performance concrete or the like are not required and are also not desired or provided in the context of the invention, since, due to the higher deformability or lower shear rigidity of lightweight concrete, the load-bearing forces would otherwise not be dissipated via the lightweight concrete base body could become.

The typical modulus of elasticity of normal concrete, as used for a building wall, is approximately E _cm ≈30,000 to 40,000 N / mm ² . In contrast, the modulus of elasticity of the lightweight concrete used in the context of the invention is between approximately 6,000 and 22,000 N / mm ² , preferably between 8,000 and 16,000 N / mm ² , most preferably approximately 14,000 N / mm ² . Due to their lower shear stiffness compared to the adjacent parts of the building, the thermal insulation elements can better compensate for the larger differences in thermal expansion behavior that occur due to the abrupt temperature jump at the thermal insulation zone. The transition area formed by the thermal insulation elements between the building wall and the floor ceiling not only acts as a thermal insulation zone in terms of building physics and as a load-bearing component in structural terms, but also as a stress-damping element to compensate for different thermal expansion.

In a preferred embodiment, a plurality of rod-shaped reinforcement means, in particular reinforcement rods, are provided in the thermal insulation element, which penetrate the base body and extend essentially vertically beyond the upper and the lower contact surface. These enable a monolithic connection of the building parts, especially in the direction of the transverse force. The reinforcement means are firmly anchored in the base body of the thermal insulation element. It is particularly provided that the rod-shaped reinforcement means penetrate the projections. It has been found that the shear force transmission between the building parts is improved via the reinforcement means integrated in the thermal insulation element if these run through the projections instead of through the area between the projections.

It can also be provided in the context of the invention that the rod-shaped reinforcement means consist of a fiber composite material. While with conventional vertically arranged reinforced concrete components with a reinforcement content of 1-2%, the steel reinforcement contributes about half to the overall thermal conductivity of the building part, the combination of lightweight concrete with a reinforcement made of a fiber composite material in the area of the thermal insulation element reduces the heat transfer by approx. 90%.

In a preferred embodiment, the projections are designed as transverse ribs arranged transversely to the laying direction. These enable particularly effective interlocking with the adjacent concrete parts of the building. The height of the projections or ribs is between 10 mm and 30 mm, in particular between 15 mm and 20 mm, in order to achieve the best effect.

In addition to the transverse ribs, at least one longitudinal rib arranged in the laying direction can also be provided. This enables additional toothing parallel to the wall and is therefore suitable for transmitting loads acting vertically on the wall, such as wind, into the building ceiling.

The present invention also relates to a method for creating load-bearing building parts, namely a vertical building wall and a floor or ceiling above or below. Between the parts of the building, a number of thermal insulation elements are laid in a line, each of which has a base body that is at least partially made of lightweight concrete as a pressure-transmitting and heat-insulating material and has an upper and a lower contact surface for vertical connection to the building parts. The thermal insulation elements each have a plurality of projections at least partially perpendicular to the direction of installation on their upper and lower contact surfaces. The thermal insulation elements are laid together, i.e. the thermal insulation elements are laid with their short end faces butt-to-butt with no space between them. The power transmission between the building wall and the floor ceiling is therefore distributed linearly over the entire length of the building wall instead of on individual support points.

As part of the construction process, a reinforcement for the lower part of the building to be made of concrete and a formwork arranged around the reinforcement are first created. The thermal insulation elements are inserted into this formwork so that they form a connection in a line for the part of the building to be constructed above. Subsequently, fresh concrete is poured into the formwork up to the height of the lower contact surface of the thermal insulation elements used in the formwork and, if necessary, the fresh concrete is compacted using a vibrating tool.

Fig. 1

eine isometrische Ansicht eines erfindungsgemäßen Wärmedämmelements

Fig. 2

eine Seitenansicht des Wärmedämmelements aus Fig. 1,

Fig. 3

eine Draufsicht auf das Wärmedämmelement aus Fig. 1,

Fig. 4

ein erstes Ausführungsbeispiel für einen wärmedämmenden Anschluss zwischen einer aus Beton erstellten, tragenden Gebäudewand und einer darüberliegenden, betonierten Geschossdecke, und

Fig. 5

ein zweites Ausführungsbeispiel für einen wärmedämmenden Anschluss zwischen einer aus Beton erstellten Gebäudewand und einer darunterliegenden, betonierten Geschossdecke.

Further features, advantages and properties of the present invention are explained below on the basis of the figures and on the basis of exemplary embodiments. It shows:

Fig. 1

an isometric view of a thermal insulation element according to the invention

Fig. 2

a side view of the thermal insulation element Fig. 1 ,

Fig. 3

a plan view of the thermal insulation element Fig. 1 ,

Fig. 4

a first embodiment for a heat-insulating connection between a load-bearing building wall made of concrete and an overlying, concrete floor ceiling, and

Fig. 5

a second embodiment for a heat-insulating connection between a building wall made of concrete and an underlying concrete floor.

In the Figures 1 to 3 A thermal insulation element 10 is shown with a base body 11 designed as a lightweight concrete molded part. It is used for the monolithic connection and for the load-bearing connection of a building wall 21, for example in the basement of a building, to the basement ceiling 22 above. It is also possible to use the thermal insulation element 10 for thermal insulation between a "cold" floor ceiling and a building wall located above it.

The thermal insulation element 10 comprises a substantially cuboid base body 11 with an upper side 12 and a lower side 13, each of which serves as contact surfaces for the basement ceiling or the end of the building wall 21 supporting it. A total of six reinforcing bars 15 protrude through the base body 11, without the invention being restricted to this, arranged in two rows.

The base body 11 of the thermal insulation element 10 consists of a lightweight concrete, which on the one hand has high pressure stability and on the other hand has good thermal insulation properties. Compared to concrete with a thermal conductivity of approximately 1.6 W / (m · K), the thermal conductivity when using a suitable lightweight concrete material is in the range of approximately 0.5 W / (m · K), which corresponds to an improvement of approximately 70%. The light concrete used essentially consists of expanded clay, fine sand, preferably light sand, flow agents and stabilizers, which prevent segregation by floating the grain and improve the workability. The compressive strength of the thermal insulation element is chosen to be sufficiently high to enable the structurally planned utilization of the underlying building wall 21 made of in-situ concrete, for example in accordance with the compressive strength class C25 / 30.

The reinforcing bars 15, which cross the base body 11 of the thermal insulation element 10 in the vertical direction, serve as shear force reinforcement for transmission along the building wall 21 and transverse forces occurring perpendicularly thereto. The reinforcing bars 15 are concreted into the lightweight concrete material of the base body 11 during the manufacture of the thermal insulation element 10.

The reinforcing bars 15 themselves are in the exemplary embodiment made of a fiber composite material which consists of glass fibers aligned in the direction of the force and a synthetic resin matrix. Such a glass fiber reinforcement bar has an extremely low thermal conductivity, which is up to 70 times lower than that of reinforcing steel, and is therefore ideally suited for use in the thermal insulation element 10. Alternatively, however, the use of reinforcing bars made of stainless steel is also possible and is included in the scope of the present invention.

Both on the upper contact surfaces 12 and on the lower contact surfaces 13, the thermal insulation element 10 has three transverse ribs 12a, 13a, which run in the direction perpendicular to its longitudinal extent. The transverse ribs 12a, 13a ensure interlocking with the adjoining parts of the building, that is to say the building wall 21 and the floor ceiling 22, and transfer lateral forces to the adjacent part of the building due to different thermal expansion.

The arrangement of the reinforcement bars 15 with respect to the base area of the base body 11 takes place in two parallel rows of three bars each. It has proven to be particularly advantageous here if the reinforcing bars 15, as shown in the exemplary embodiment, are arranged such that they run through the ribs 12a, 13a instead of through the incisions between the ribs 12a, 13a. For this reason, it is also advantageous that the ribs 12a, 13a on the top 12 and bottom 13, or in the general case projections of any shape with areas extending transversely to the longitudinal direction, correspond to one another and are arranged in mirror image or in vertical alignment with one another. Of course, base bodies with four or more ribs and a correspondingly larger number of test bars can also be used.

The base body 11 of the thermal insulation element 10 has a length of approximately 300 mm in the exemplary embodiment, without the invention being restricted to this. The height without ribs is 100 mm and thus corresponds to the usual thickness of a subsequently installed thermal insulation layer. The height of the individual ribs 12a, 13a is 15 mm in each case. The width of the base body corresponds to the planned wall thickness of the building wall, e.g. 180 mm.

In Figure 4 shows a connection situation between a building wall 21, for example in the basement of a building, and the ceiling 22 above it, for example the basement ceiling. The uppermost end of the building wall 21 is formed by a line of thermal insulation elements 10 set in a line in the composite, that is to say without a space in between. Their reinforcing bars 15 are concreted into the building wall 21 made of in-situ concrete. The building wall 21 was concreted from below to the thermal insulation elements 10. The floor slab 22, which is also made of in-situ concrete, is located above the location of the heat insulation elements 15. The reinforcing bars projecting beyond the heat insulation element 10 are concreted into the floor slab 22. The ribs 12a, 13a create an effective toothing in the direction of the wall profile between the building wall 21, the position of thermal insulation elements 10 and the floor ceiling 22 in the manner of a toothed joint.

For the production, a reinforcement for the building wall 21 is first created in a conventional manner and provided with a formwork. The thermal insulation elements are inserted into the formwork as the top end and attached to the formwork with aids. Then the formwork is filled with fresh concrete up to the lower edge of the thermal insulation elements and this is compacted. For filling and compaction, individual thermal insulation elements 15 can be removed and reinserted after compaction. At the same time, it would be possible to provide filling openings in the thermal insulation elements which can be closed after the filling. Another possibility would be to first fill the formwork with fresh concrete and compact it and then insert the position of the thermal insulation elements on top of it in the still liquid in-situ concrete.

As soon as this has set, the process of creating the floor ceiling 22 can be continued in a manner known per se, the reinforcement of which with the reinforcing bars 15 made of fiber composite material projecting beyond the upper contact surface 13 of the thermal insulation elements 10 in the in-situ concrete of the floor slab. To create the floor slab 22, formwork is installed above or adjacent to the thermal insulation elements 10 and reinforcement is laid for the floor slab. Then the floor slab is concreted in the usual way. Finally, a thermal insulation layer made of a highly insulating material can be applied below the floor ceiling 22, the thickness of which essentially corresponds to the height of the thermal insulation elements 10. Mineral insulation boards or wood-wool multi-layer boards can be installed as thermal insulation layers.

In an alternative, in Figure 5 Embodiment shown, the thermal insulation elements are arranged as the lowest layer between a building wall and an underlying floor or floor slab - which is also referred to in the general sense in the context of the present invention as a floor ceiling. This embodiment is used for a "cold" floor ceiling, in which a thermal insulation layer is installed above the floor ceiling.

For the manufacture, formwork and reinforcement are first created for the lower floor ceiling 22. The thermal insulation elements 10 are fastened to the upper edge of the formwork or at a corresponding height on the reinforcement. Subsequently, the floor ceiling 22 is poured from fresh concrete and compacted in a conventional manner. The downward-facing reinforcing bars 15 of the thermal insulation elements 10 are also concreted in. After the concrete has set or hardened, a reinforcement for the building wall 21 is created above the thermal insulation elements 10 and a formwork for the building wall is erected around it and including the thermal insulation elements 10 protruding from the concrete floor ceiling 22. Then it is concreted in a conventional manner.

Claims (11)

Thermal insulation element for heat decoupling between load-bearing parts of the building to be made of concrete, namely a vertical building wall (21) and a floor or ceiling above (22), the thermal insulation element (10) having a basic body (11) to be laid linearly between the building parts consists at least partially of a pressure-transmitting and heat-insulating material, namely lightweight concrete, and has an upper and a lower contact surface (12, 13) for vertical connection to the building parts (21, 22),
characterized in that
the thermal insulation element on its upper and lower contact surface (13) each has a plurality of projections (12a, 13a) running at least partially perpendicular to the laying direction. Thermal insulation element according to Claim 1, which has a plurality of rod-shaped reinforcement means, in particular reinforcement rods (15), which penetrate the base body (11) and extend essentially vertically beyond the upper and lower contact surfaces (12, 13). Thermal insulation element according to Claim 2, in which the rod-shaped reinforcement means (15) penetrate the projections (12a, 13a). Thermal insulation element according to claim 2 or 3, wherein the rod-shaped reinforcement means (15) consist of a fiber composite material. Thermal insulation element according to one of the preceding claims, in which the rod-shaped reinforcement means (15) are non-positively connected to the base body (11). Thermal insulation element according to one of the preceding claims, wherein the base body (11) is essentially cuboid and the longitudinal axis of the base body (11) specifies the laying direction, to which the projections (12a, 13a) are aligned in a transverse axis of the base body (11). Thermal insulation element according to one of the preceding claims, in which the projections (12a, 13a) are designed as transverse ribs arranged transversely to the laying direction. Thermal insulation element according to Claim 7, in which, in addition to the transverse ribs (12a, 13a), at least one longitudinal rib arranged in the laying direction is provided. Method for creating load-bearing building parts, namely a vertical building wall (21) and a floor or ceiling (22) above or below, wherein a plurality of thermal insulation elements (10) are laid linearly between the building parts, each having a base body (11), which at least consists partly of a compressive force-transmitting and heat-insulating material, namely lightweight concrete, and has an upper and a lower contact surface (12, 13) for vertical connection to the building parts (21, 22), and wherein the heat insulation elements on their upper and lower contact surface (13) each have a plurality of projections (12a, 13a) running at least partially perpendicular to the direction of installation. Method according to Claim 9, in which the base bodies (11) of the heat insulation elements (10) are essentially cuboid and the longitudinal axis of the base bodies (11) determines the direction of installation, and in which the heat insulation elements (10) each have a short end face with no gap to be laid in abutment. Method according to Claim 9 or 10, in which a reinforcement for the lower part of the building (21, 22) to be made of concrete and a formwork arranged around the reinforcement is created, in which the thermal insulation elements (10) are inserted into the formwork, so that these form a connection in a line for the part of the building (22, 21) to be created and in which fresh concrete is poured into the formwork up to the height of the lower contact surface (13) of the thermal insulation elements (10) used in the formwork and, if necessary, the fresh concrete by means of a Vibrating tool is compressed.

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