EP3112542B1 - Device and method for heat decoupling of concreted parts of buildings - Google Patents

Description

The present invention relates to a load-bearing, vertical building part made of concrete, in particular a support, with a first bearing surface for load-bearing connection to a horizontal building part to be made above or below it of concrete, in particular a floor or a floor slab, and a method for producing such Part of the building. In addition, the invention relates to a thermal insulation element for heat decoupling between load-bearing parts of the building to be made of concrete, preferably between a vertical part of the building, in particular a support, and a horizontal part of the building above or below it, in particular a floor or a floor slab.

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 car park, 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 it, 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 can only be removed with difficulty from external thermal insulation. In underground car parks, for example, the upper section of the load-bearing concrete columns facing the floor ceiling is also covered with thermal insulation. This is not only complex and visually unappealing, but also leads to unsatisfactory building physics results and also reduces the parking space available in the underground car park.

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 supporting 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 be made of foam glass or expanded polystyrene hard foam, for example, and the pressure elements can be made of concrete, fiber concrete or fiber plastic. This document discloses the features of the preambles of independent claims 1 and 8.

The approach propagated here for vertical heat decoupling of building parts to be made of concrete thus consists in reducing the contact area between the building parts in order to reduce heat transfer. However, if force is introduced into plate structures, such as a floor slab, concentrated on a reduced area, the risk that the plate structure may break through, known as punching, may increase at a force introduction point.

On a concrete floor slab, there may also be slight subsidence and / or elastic deformation due to the load on it. This leads to a redistribution of forces at the support points at which the floor ceiling is supported by the vertical parts of the building below. Such a rotation of the support can lead to an overload of the pressure element. If several pressure elements are used in a single column and one of them fails and breaks, it is distributed the load on the neighboring pressure elements, which would then also be overloaded. This can lead to a chain reaction with fatal consequences for the statics of the building.

It is therefore an object of the invention to provide a load-bearing, vertical part of the building, in particular a support, with a first bearing surface for load-bearing connection to a horizontal part of the building, in particular a floor slab, to be made of concrete, and a corresponding method for Specify the creation of such a part of the building, which on the one hand reduces the heat transfer between the parts of the building, and on the other hand reduces the risk of local overload at the support points.

Another object of the invention is to provide a thermal insulation element for heat decoupling between load-bearing parts of the building to be made of concrete, preferably between a vertical part of the building, in particular a column, and a horizontal part of the building, in particular a floor slab, above or below, in which the Risk of local overload at the support points is reduced.

The object is achieved with regard to the thermal insulation element by the features of claim 1 or claim 8, with regard to the building part by the features of claim 9 and with regard to the method by the features of claim 10. Advantageous configurations can be found in the dependent claims.

In the case of a load-bearing, vertical part of a building made of concrete, in particular a column, with a first bearing surface for load-bearing connection to a horizontal part of the building to be created above or below it, in particular a floor slab, in which the vertical part of the building has reinforcement with one or more The object is achieved according to the invention in that the rod-shaped reinforcement means, in particular reinforcement bars, extend essentially vertically beyond the first support surface in that an area of the vertical part of the building adjacent to the first support surface serves as a thermal insulation element for heat decoupling between the vertical part of the building and the horizontal to be created above or below it Part of the building is designed so that the area forming the thermal insulation element consists at least partially of a pressure-transmitting and heat-insulating material, namely lightweight concrete, and that the reinforcing bars extending beyond the upper contact surface consist of a fiber composite material and through the first area of the vertical area forming the thermal insulation element Part of the building extends substantially vertically into an adjoining second area of the vertical part of the building, in which it is made of reinforced normal concrete.

The thermal insulation element thus consists, at least in part, of a pressure-transmitting and heat-insulating lightweight concrete. 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 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.

A concrete with a dry bulk density of maximum 2000 kg / m ^{3 is} defined under lightweight concrete according to the applicable regulations. The low density in comparison to normal concrete is achieved by appropriate manufacturing processes and different lightweight concrete grains, preferably grains with grain porosity such as expanded clay. Depending on its composition, lightweight concrete has a thermal conductivity between 0.2 and 1.6 W / (m · K).

Through the use of a solid or hollow-block heat insulation element made of lightweight concrete, with the same or less heat loss, a much larger contact surface is available than would be the case if high-pressure-resistant pressure elements were used. In contrast to the known pressure elements, the larger load transfer avoids the risk of settlement or elastic deformation on the part of the building above or smaller weak points in the connection to the part of the building below, for example due to the formation of voids or sedimentation, resulting in local overloading and thus one Failure of the thermal insulation element.

The improved and more secure connection of the building parts made of concrete is achieved above all by the fact that, with the same strength class, the elastic modulus of light concrete is only about 30 to 70% of the values of normal concrete. Therefore, the elastic deformations with the same stress (tension) are on average 1.5 to 3 times as large. For this reason, the thermal insulation element made of lightweight concrete also acts as a stress-damping element and is able to compensate for smaller settlements and elastic deformations of the part of the building above and to ensure a more even distribution and force transmission from eccentric contact forces to or into the part of the building below.

The much lower modulus of elasticity of the lightweight concrete used has a particularly favorable effect on load centers and bearing twists, which result in increased edge pressures. Due to its elastic properties, the thermal insulation element acts as a "centering element", so to speak. In contrast to this, the compression with a central load is of minor importance.

The typical modulus of elasticity of normal concrete, as used for a column, is approximately E _cm ≈30,000 to 40,000 N / mm ² . In contrast, the modulus of elasticity of the lightweight concrete in the context of the invention is between approximately 9,000 and 22,000 N / mm ² , preferably between 12,000 and 16,000 N / mm ² , most preferably approximately 14,000 N / mm ² .

While in conventional vertically arranged reinforced concrete components with a reinforcement content of 3-4%, the steel reinforcement contributes about half to the overall thermal conductivity of the building part, the combination of lightweight concrete with reinforcement made of a fiber composite material according to the invention reduces the heat transfer in the area of the thermal insulation element by approx. 90% .

The above-mentioned upper area of the vertical part of the building thus acts not only as a thermal insulation element in terms of building physics and as a load-bearing component in structural terms, but also as a stress-damping element to compensate for mechanical deformations. It does not matter whether the thermal insulation element is sent to the construction site as a lightweight precast element delivered, installed there in the formwork for the vertical part of the building and the latter is concreted from below against the lower contact surface of the thermal insulation element, or whether the thermal insulation element in the formwork of the vertical part of the building is made on site from special, lightweight in-situ concrete.

In a preferred embodiment, however, the thermal insulation element is designed as a prefabricated molded part. The invention therefore also relates to a thermal insulation element for heat decoupling between load-bearing parts of the building to be made of concrete, preferably between a vertical part of the building, in particular a pillar, and a horizontal part of the building above or below it, in particular a floor slab. The thermal insulation element has a base body with an upper and a lower contact surface for vertical connection to the parts of the building. According to the invention, the base body of the thermal insulation element consists at least partially of a compressive force-transmitting and heat-insulating material, namely lightweight concrete, and has one or more rod-shaped reinforcement means, in particular reinforcement bars, which penetrate the base body and extend substantially vertically beyond the upper and the lower contact surface, in particular reinforcement bars on.

Lightweight concrete can be manufactured and processed better under factory conditions than on the construction site, so that factory-made thermal insulation elements can achieve higher compressive strength classes than those made from in-situ concrete.

In a preferred embodiment of such a prefabricated thermal insulation element, the reinforcing bars are inserted in sleeves which are embedded in the material transmitting the pressure force. The sleeves serve as lost formwork for the subsequent insertion of the reinforcement bars. Reinforcing bars made of fiber composite material can transmit very high tensile forces, but in contrast, significantly lower pressure forces can lead to the destruction of such reinforcing bars. The use of sleeves prevents form-fitting embedding of the reinforcing bars in the surrounding concrete, which is normally intended for concrete reinforcement and is almost essential. If there is a compressive load, for example due to subsidence in the building, the reinforcement bars can deform elastically in their sleeves until the compressive forces are completely absorbed by the surrounding compressive stable lightweight concrete insulation body, so that a damaging compressive force load on the reinforcing bars is avoided.

The reinforcing bars in the thermal insulation element are expediently designed as tensile reinforcement, since the connection between the support and the floor slab above it can be considered statically as an articulated connection. Thus, by using the sleeves for the connection-free implementation of a fiber composite reinforcement, a stable and permanent connection or monolithic connection between the column and the floor slab in accordance with the structural requirements is achieved with continuous reinforcement.

In an advantageous development of the thermal insulation element, it has at least one through opening which extends from the upper to the lower contact surface and is designed to carry out a compacting device for fresh concrete. The through opening thus serves as an immersion point for an internal vibrator. The passage opening is preferably arranged approximately centrally in the thermal insulation element.

This is based on the knowledge that when installing and then concreting against the underside of the thermal insulation element, inadequate and undefined compression of the in-situ concrete below the thermal insulation element can occur, which also depends heavily on the composition of the in-situ concrete used. According to the knowledge of the invention, two processes on the underside of the thermal insulation element when the in-situ concrete sets can result in the load-bearing connection of the thermal insulation element to the underlying building part being defective. On the one hand, rising air bubbles, so-called compression pores, can lead to the formation of voids on the underside of the thermal insulation element and thus ensure a structurally inadequate connection. An even more critical process is sedimentation in in-situ concrete that has not yet set, in which heavier aggregates slowly sink and water or cement paste is separated on the concrete surface. In this case, after the concrete part has set and dried out Large hollow spaces remain between the thermal insulation element and the concrete part underneath, which are not visible from the outside.

In order to avoid this, a passage opening is provided in the thermal insulation element, through which a compaction device such as the vibrating bottle of a concrete vibrator can be passed, in order to compact or recompact the in-situ concrete underneath after the thermal insulation element has been installed. By means of this compression or post-compression, the problems described can be avoided and a reliable connection of the thermal insulation element to the part of the building located below can be achieved. The through opening can also be used as a filling opening for in-situ concrete.

A further advantage of the present invention results if the lower contact surface of the thermal insulation element has a surface with a three-dimensional profile. Suitable profiling of the surface further reduces defects in the connection between the thermal insulation element and the freshly concreted part of the building underneath. For example, the surface may have elevations and depressions as well as inclined surfaces, furrows, or the like, so that in the event of sedimentation, the surface water that settles out can run or settle in non-critical areas, while one in areas of the thermal insulation element that are critical for the static connection there is an intimate connection to the fresh concrete of the part of the building below.

In this context, an embodiment is considered to be particularly preferred in which the lower contact surface has a funnel-shaped or curved surface in the direction of the through opening. This ensures that, in the event of sedimentation, the surface water that settles out is displaced in the direction of the passage opening or only forms in this area, which does not contribute to the statics of the construction anyway.

Furthermore, it proves to be advantageous if a reinforcement bracket is arranged in the interior of the thermal insulation element that transmits pressure. Such a reinforcement bracket in the form of a self-contained reinforcement ring with, for example, a circular or rounded polygonal base, which is arranged in a plane which is essentially parallel with respect to the bearing surfaces, can further increase the resistance to pressure of the thermal insulation element by minimizing the transverse expansion of the thermal insulation element under pressure.

In addition to the through opening for the vibrating tool, further potting openings can be provided in the thermal insulation element, via which additional potting compound, such as potting mortar, can be filled if necessary after the concrete has hardened, in order to fill any cavities that still exist between the part of the building underneath and the thermal insulation element. The potting openings in question are preferably closed by means of removable blind plugs, so that they cannot be blocked by in-situ concrete when the thermal insulation element is installed.

Furthermore, it is preferred within the scope of the present invention that a sealing plug is provided, with which the through opening can be subsequently closed. It is further preferred here that the sealing plug consists of a heat-insulating but non-load-bearing material, such as extruded polystyrene. In addition, such a stopper can be conically shaped so that it can be inserted sealingly into the through opening, which preferably also tapers downward. This ensures that after the installation of the thermal insulation element, no thermal bridge remains through the through opening, for example due to in-situ concrete entering the through opening when concreting the floor above.

In order to enable a vibrating tool to be carried out, for example the vibrating bottle of a concrete vibrator, the through opening has an opening dimension that is large enough to enable vibrating bottles customary on the construction site to be carried out, in particular at least 50 mm, preferably between 60 and 80 mm.

In an alternative embodiment of the invention, in the case of a thermal insulation element of the type mentioned at the outset, the object can also be achieved in that instead of rod-shaped reinforcement means in the base body one or more of these vertically from the upper to the lower contact surface penetrating sleeves are used, which are embedded as lost formwork in the pressure-transmitting material and are designed for subsequent use or for the connection-free implementation of rod-shaped reinforcement means, in particular reinforcement bars, which extend essentially vertically beyond the upper and the lower contact surface.

On the one hand, as already stated, the use of sleeves prevents the reinforcing bars from being positively embedded in the surrounding concrete, so that when a fiber composite reinforcement is used, a harmful compressive force load on the reinforcing bars is avoided. On the other hand, such a structure has considerable advantages in the production of thermal insulation elements according to the invention. If such a thermal insulation element is manufactured under factory conditions, it is easier to use sleeves in a formwork for the thermal insulation element than reinforcement bars, which are intended to penetrate the thermal insulation element on both sides and which have to be sealed against the formwork. Storage is also significantly simplified if prefabricated thermal insulation elements are designed without bulky reinforcing bars and the latter are only inserted into the sleeves of the thermal insulation element at the construction site when the thermal insulation element is installed in a support or wall. Such a thermal insulation element also enables the use of reinforcing bars made of stainless steel, for example, if no reinforcing bars made of fiber composite material are at hand or such are not desired for other reasons.

The invention further relates to a method for creating a vertical part of a building made of concrete, in particular a support, with a first bearing surface for load-bearing connection to a horizontal part of the building to be created above or below it from concrete, in particular a floor slab. Here, a first area of the vertical part of the building is created from reinforced normal concrete. A second area of the vertical part of the building, located between the first bearing surface and the first area of the vertical part of the building, is at least partially formed from a pressure-transmitting and heat-insulating material, namely lightweight concrete, in order to act as a thermal insulation element for heat decoupling between the vertical part of the building and the horizontal to be created above or below it Part of the building serve. In addition, rod-shaped reinforcing means, in particular reinforcing bars, made of a fiber composite material are installed in the second area of the vertical part of the building, which extends essentially vertically through the second area of the vertical part of the building into the adjoining first area and beyond the first bearing surface.

The thermal insulation element can be a prefabricated lightweight precast element. In this case, reinforcement and formwork arranged around the reinforcement are created for the first area of the vertical part of the building. Fresh formwork concrete is poured into the formwork over the full height of the first area of the vertical part of the building. The second area of the vertical part of the building is formed by the prefabricated thermal insulation element, which is inserted into the formwork.

The first area can either be concreted before the thermal insulation element is inserted, or the thermal insulation element can also be inserted into the formwork before the first area is concreted.

In the first case, the first, lower area is first concreted by pouring in-situ concrete into the formwork and compacting it. Then, in a second step, the thermal insulation element is inserted into the formwork. The reinforcing bars that protrude downwards beyond the thermal insulation element are pressed into the fresh in-situ concrete of the first area. Subsequently, the concrete is preferably re-compacted by means of a compacting device which is passed through a through opening in the thermal insulation element. The passage opening can then preferably be closed by means of a sealing plug. Then the horizontal part of the building above it, for example a floor ceiling, can be created above the thermal insulation element in a conventional manner.

By re-compacting the still fresh in-situ concrete of the vertical part of the building after inserting the thermal insulation element, it is ensured that there is intimate contact with its lower contact surface and cavities due to the formation of voids and sedimentation between the thermal insulation element and the part of the building below it are avoided.

In the second case, the thermal insulation element can also be installed before the formwork is filled with in-situ concrete. In this case, a passage opening provided in the thermal insulation element can initially be used as a filling opening for filling the in-situ concrete. The filled concrete is then compacted by inserting the vibrating tool into the fresh in-situ concrete through the through opening.

Alternatively, the thermal insulation element can also be created on site from in-situ concrete. For this purpose, reinforcement and formwork arranged around the reinforcement are first created for the first, lower area of the vertical part of the building. The reinforcement bars made of fiber composite material are used in an upper area of the formwork, which corresponds to the second area of the vertical part of the building. Fresh formwork concrete is poured into the formwork up to the height of the first area of the vertical part of the building. The second area of the vertical part of the building is then created by pouring fresh lightweight concrete into the upper area of the formwork.

The reinforcement bars in the upper area can be inserted into the lower area of the formwork before the in-situ concrete is poured in and connected to the reinforcement in the lower area. Alternatively, the reinforcing bars can only be pressed into the still fresh in-situ concrete after the in-situ concrete has been filled and compacted into the lower formwork area. When filling in the fresh lightweight concrete, you can wait until the in-situ concrete has set in the lower formwork area. With proper surface treatment, the lightweight concrete can also be installed with fully hardened in-situ concrete.

In the context of the present invention, a horizontal part of the building, that is to say, for example, a floor ceiling, is also to be understood as one in which an offset is provided adjacent to the vertical part of the building, for example a support. For example, a column can be created up to just below a floor slab above it. The formwork for the floor slab can then be connected to the formwork still left on the support and this can be made of in-situ concrete, leaving a slight free space above the column inside the formwork is also filled with in-situ concrete of the floor slab and forms an offset.

Fig. 1

einen Schnitt durch eine aus Beton erstellte Stütze und der darüber und darunter befindlichen Gebäudeteile,

Fig. 2

eine isometrische Ansicht eines erfindungsgemäßen Wärmedämmelements aus einem druckkraftübertragenden Werkstoff, nämlich Leichtbeton,

Fig. 3

eine Draufsicht auf das Wärmedämmelement aus Fig. 2,

Fig. 4

einen vertikalen Schnitt durch das Wärmedämmelement entlang der Schnittlinie C-C aus Fig. 3,

Fig. 5

eine Weiterbildung des Wärmedämmelements aus Fig. 2 in einer Seitenansicht,

Fig. 6

einen Querschnitt durch die Stütze aus Figur 1,

Fig. 7

die Armierung der Stütze aus Figur 1 mit dem Wärmedämmelement vor dem Verfüllen der Schalung der Stütze mit Ortbeton,

Fig. 8

die mit einer Schalung versehene Stütze nach dem Verfüllen mit Beton,

Fig. 9

ein vergrößerter Ausschnitt aus Figur 8 und

Fig. 10

ein alternatives Ausführungsbeispiel mit im Fußbereich einer Stütze angeordnetem Wärmedämmelement.

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

a section through a column made of concrete and the parts of the building above and below it,

Fig. 2

2 shows an isometric view of a thermal insulation element according to the invention made of a material that transmits pressure, namely lightweight concrete,

Fig. 3

a plan view of the thermal insulation element Fig. 2 ,

Fig. 4

a vertical section through the thermal insulation element along the section line CC Fig. 3 ,

Fig. 5

advanced training in thermal insulation Fig. 2 in a side view,

Fig. 6

a cross section through the support Figure 1 ,

Fig. 7

the reinforcement of the support Figure 1 with the thermal insulation element before filling the formwork of the column with in-situ concrete,

Fig. 8

the column with formwork after filling with concrete,

Fig. 9

an enlarged section from Figure 8 and

Fig. 10

an alternative embodiment with a thermal insulation element arranged in the foot region of a support.

At a first, in Figure 1 shown embodiment, a support 1 is provided, which is monolithically connected to a base plate 2 and a floor 3. The upper area 4 of the prop is made of lightweight concrete while the lower area 1 'consists of normal in-situ concrete (normal concrete). The support 1 can have a clear height of 220 cm, for example. The upper area accounts for 10 cm. A thermal insulation layer 5 made of a highly insulating material is applied below the floor ceiling, the thickness of which essentially corresponds to at least the height of the upper region 4 of the support 1. Mineral insulation boards or wood-wool multilayer boards can be installed as the thermal insulation layer 6, for example.

To the in Figure 1 To create shown building parts, the base plate 2 is first concreted with a reinforcement 2 'in a conventional manner. To connect the support 1 to the floor slab, reinforcement bars 2 "protrude vertically upward from the horizontal reinforcement 2 'of the floor slab. A reinforcement 6 made of structural steel arranged inside the support 1 is then connected to this. The reinforcement 6 comprises four vertical reinforcement bars 6 'and a plurality of reinforcement brackets 6 ", spaced apart in the vertical direction, with an approximately square plan. In the upper area 4, instead of reinforcing bars 6 'made of structural steel, four reinforcing bars 7 made of a fiber composite material, such as the fiber composite material sold by the applicant under the name ComBAR (R). In the upper area 4, the reinforcement bars 7 surround a reinforcement arranged at right angles thereto, for example a reinforcement bracket 7 'made of stainless steel. The reinforcement bars 7 protrude beyond the upper area 4 of the column in order to enable a monolithic connection to the floor ceiling 3 to be created later. In addition, the reinforcing bars 7 also protrude from the upper area 4 of the support, which serves as a thermal insulation element, into the lower area 1 'made of normal concrete.

A formwork that is closed on all sides (cf. Fig. 8 ) set up for support 1. In-situ concrete is then poured into this, namely up to the height of the lower region 1 ', that is to say approximately 210 cm high in the exemplary embodiment. The in-situ concrete, a typical construction-ready normal concrete, is then compacted with an internal vibrator. When the in-situ concrete has set, fresh lightweight concrete is poured into the existing formwork in the upper area 4 above and also compacted. As soon as this has set, the process of creating the floor ceiling 3 can also be carried out in a manner known per se, the reinforcement of which 3 'is cast with the reinforcing bars 7, which project beyond the upper contact surface of the support 1 and are made of fiber composite material in the in-situ concrete of the floor slab.

As an alternative to creating the upper area 4 of the support 1 serving as a heat insulation element from a special, lightweight in-situ concrete, a prefabricated molded part can also be installed as a heat insulation element in the formwork of the support. In this case, the formwork of the column is either filled with in-situ concrete through an opening in the molded part, or the formwork is only filled with in-situ concrete up to the height of the lower area 1 'and the molded part is then inserted into the formwork from above and to the other pressed fresh in-situ concrete of the column 1. Here, it is expedient to introduce an internal vibrator through a central opening in the molded part in order to compact the in-situ concrete in the connection area to the molded part.

In the Figures 2 to 4 A corresponding thermal insulation element 10 comprising such a molded part is shown. It is used for the monolithic connection and for the load-bearing connection of a concrete support 1, for example in the basement of a building, to the basement ceiling 3 above. The thermal insulation element 10 has a cuboid base element 11 with an upper side 12 and an underside 13, each of which serves as a support surface for the basement ceiling or the end of the support 1 supporting it. In the middle of the cuboid thermal insulation element 10 there is a central through opening 14, which extends from the upper side 12 to the lower side 13 of the thermal insulation element 11. Four reinforcing bars 15 made of a fiber composite material protrude through the base body 11. The underside 13 of the base body 11 has a three-dimensional profile in the form of a funnel-shaped recess 16 extending in the direction of the through opening 14. In the interior of the base body 11, a reinforcement bracket 17 is also embedded, which lies around the reinforcement bars 15 and gives the thermal insulation element 10 additional stability.

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 about 1.6 W / (m · K), the thermal conductivity is when using a suitable one Light concrete material in the range of about 0.5 W / (m · K), which corresponds to an improvement of about 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 workability.

The compressive strength of the thermal insulation element is sufficiently high to allow the statically planned use of the underlying support made of in-situ concrete, for example in accordance with the compressive strength class C25 / 30. However, the compressive strength of the thermal insulation element preferably corresponds to at least 1.5 times the statically required value. This ensures that there are also safety reserves in the event of any missing surfaces on the connecting surface between the thermal insulation element and the support, so that the thermal insulation element remains statically stable even at points with higher loads.

The reinforcement bars 15, which cross the base body 11 of the thermal insulation element 10 in the vertical direction, serve primarily as tension bars for the transmission of any tensile forces that may occur. The reinforcing bars 15 can be concreted into the lightweight concrete material of the cuboid base body 11 during the manufacture of the thermal insulation element 10. Alternatively, to simplify the manufacture of the thermal insulation element, it is possible to use sleeves during manufacture as a kind of lost circuit through which the reinforcing bars 15 are inserted after the lightweight concrete element 11 has hardened.

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 100 times lower than that of reinforcing steel, and is therefore ideally suited for use in the thermal insulation element. Alternatively, however, the use of reinforcing bars made of stainless steel is also possible and is included in the scope of the present invention, in particular when using sleeves as lost formwork.

The dimensions of the reinforcement bars 15, without the invention being restricted to this, are 16 mm in diameter and 930 mm in length in the exemplary embodiment. The arrangement of the reinforcing bars 15 with respect to the base area of the base body 11 is chosen slightly outside the main diagonals. The reason for this is that the reinforcement rods 6 ′ of the support 1 are already located in the corners of the support 1, into which the reinforcement bars 15 of the thermal insulation element 10 are installed.

The reinforcement bracket 17 consists of a ring bent, stainless steel, which is welded at the connection point. The reinforcement bracket 17 has a diameter of approximately 200 mm with a material thickness of 8 to 10 mm.

The base body 11 of the thermal insulation element 10 has an edge length of 250 x 250 mm in the exemplary embodiment. The height is 100 mm and therefore corresponds to the usual thickness of a subsequently installed thermal insulation layer. The through opening runs, especially in Fig. 4 can be seen, slightly conical in that the through opening 14 tapers from an upper dimension of 70 mm to a lower dimension of 65 mm. The passage opening can be closed by means of a corresponding, likewise slightly conical plug (not shown).

Fig. 5 shows the thermal insulation element in a side view, wherein additional peripheral seals 18 are attached to the base body 11. The seals 18 can be designed, for example, as rubber lips or conventional sealing tapes. They serve to seal the base body 11 of the thermal insulation element 10 so that it is edge-tight against a formwork for the support to be created underneath, in order to prevent concrete from rising or air from penetrating.

Fig. 6 shows the installation situation of the thermal insulation element in relation to a support 1. The cross section shown runs below the base body 11 of the thermal insulation element 10. The support 1 made of in-situ concrete has reinforcement with four vertical reinforcement bars 6 'arranged in the corners of the support 1 and a large number Reinforcement stirrups 6 "running approximately square around the reinforcement bars 6 '. The reinforcement bars 15 of the thermal insulation element 10 are each slightly offset next to one of the reinforcing bars 6 'of the support 1. The in Fig. 6 drawn line BB corresponds to the cut of the in Fig. 7 shown longitudinal section through the column reinforcement.

In Fig. 7 the reinforcement of the support 1 together with the thermal insulation element 10 is shown in a longitudinal section. The cut corresponds to the cut line BB Fig. 6 . The reinforcement of the support 1 consists of four vertical reinforcement bars 6 'arranged in the corners of the support, which can be made, for example, of structural steel with a bar diameter of 28 mm and a length of 2000 mm, and a plurality of reinforcement brackets running horizontally around the reinforcement bars 6' 6 "with an approximately square plan. Above the column reinforcement is the thermal insulation element 10, the reinforcement bars 15 of which project downward into the column reinforcement.

The reinforcement content of column 1 is approximately 3-4%. With a typical thermal conductivity of the structural steel of approx. 50 W / (m · K) compared to concrete with 1.6 W / (m · K), it contributes roughly half to the total thermal conductivity of the column. By using the combination of lightweight concrete and glass fiber reinforcement in the area of the thermal insulation element 10, the heat transfer between the column 1 and the floor ceiling 3 can thus be reduced by approximately 90% compared to a direct monolithic connection.

To create the column 1, as in Figure 8 shown in the upper half, a formwork 19 is built around the column reinforcement 6 ', 6 "and the lower area 1' is filled with in-situ concrete. This is compacted in a conventional manner with an internal vibrator. The thermal insulation element 10 is then inserted into the formwork 19 from above and its reinforcing bars 15 pressed into the still liquid in-situ concrete The base body 11 is pressed against the fresh in-situ concrete until the liquid concrete rises slightly upwards in the through opening 14, so that it is ensured that the column 1 and the base body are between the concrete 11 of the thermal insulation element 10 is no longer present, then the vibrating bottle of a concrete vibrator is passed through the passage opening 14 into the fresh in-situ concrete located below, in order to compact it again the thermal insulation element 10 can be slightly raised by the volume of the concrete displaced by the vibrating bottle. When pulling out the vibrating bottle, care is therefore taken to ensure that the thermal insulation element 10 drops again by this volume by the thermal insulation element 10 being pressed down accordingly when the vibrator is pulled out. The circumferential seal 18 prevents air from entering between the formwork and the thermal insulation element or the thermal insulation element 10 from tilting in the formwork. In Figure 9 the detail designated as detail D is drawn out enlarged again by one of the seals 18.

The post-compression of the still liquid fresh concrete through the through opening 14 of the heat insulation element 10 leads to an intimate connection of the heat insulation element 10 with the in-situ concrete located underneath. In particular, hollow places due to the formation of voids or sedimentation in the fresh concrete between the thermal insulation element 10 and the support 1 are prevented. The conical profile on the underside of the base body 11, in particular, contributes to this, due to the rising air bubbles or cement water separated on the surface, collecting mainly in the central region of the passage opening 14.

After the support has been concreted and compacted through the through opening 14, any concrete residues remaining in the through opening 14 are removed. The passage opening 14 is then closed by means of a conical stopper (not shown). The sealing plug can be made of an insulating material such as polystyrene or the like. exist and serves to prevent the penetration of in-situ concrete into the through opening 14 when the floor 3 is subsequently created. In this way, any thermal bridges due to a concrete filling in the through opening 14 are avoided. Subsequently, the storey ceiling 3 above is created above the thermal insulation element 10 in a conventional manner.

In addition to compacting or post-compacting, the passage opening 14 can also be used as a filling opening for filling the formwork for the support 1 with in-situ concrete. In this case, the thermal insulation element is inserted into the still empty formwork of the column 1 and, if necessary, the reinforcement bars 15 are connected to the column reinforcement. Then will Fresh concrete is poured into the formwork through the passage opening 14 of the thermal insulation element and then compacted by inserting a vibrating bottle of an internal vibrator through the passage opening 14. Here too, the fresh concrete is compacted against the underside of the thermal insulation element from above through the passage opening 14. Alternatively, the support 1 can also be made from self-compacting concrete, or the support 1 can be compacted by an external vibrator. In the latter two cases, the through opening 14 thus serves only as a filling opening.

In addition to installation in the upper area of a support, installation in the foot area of a support is also conceivable. Such an arrangement is shown in an alternative embodiment in Figure 10 shown. The support 1 is arranged here between the base plate 2 and the upper floor 3. A thermal insulation element 10 according to the invention is installed in the foot region of the support 1, the reinforcing bars 15 of which protrude from the base plate 2 into the upper region of the support 1 and are connected there to the reinforcement 6 of the support 1. In this case, a heat insulation layer 5 made of insulation boards of a known type is attached to the top of the floor panel 2.

The production can take place in such a way that the thermal insulation element 10 is connected to the reinforcement 2 'before the base plate 2 is concreted. The base plate 2 is then poured from in-situ concrete, so that the concrete rises against the thermal insulation element 10 from below. In order to obtain a good and space-free connection here, the in-situ concrete can in turn be compacted through the central through opening with a vibrating tool. After curing, the reinforcement 6 of the support is created and connected to the reinforcement bars 15 of the thermal insulation element. The formwork for the support 1 is then built up around the thermal insulation element 10 and then the support 1 is poured and compacted from in-situ concrete in a conventional manner.

The dimensions of the thermal insulation element itself can be adapted to the component located below and / or above it. In particular, thermal insulation elements can be adapted to the typical cross sections of supports with a round, square or rectangular outline.

Typical dimensions of round supports are diameters of 24 and 30 cm, or of supports with a rectangular layout of 25 x 25 cm and 30 x 30 cm. Thermal insulation elements with such a geometry can also be combined as desired to form larger supports or retaining walls.

The thermal insulation elements described here are particularly suitable for use with pendulum supports and wall supports with low clamping moments. In addition, use with load-bearing outer walls is also possible, in that the heat insulation elements are installed at a suitable distance from one another and any remaining gaps between the individual heat insulation elements are filled with non-load-bearing insulation material.

In addition to the conical shape shown here, the geometrical design of the profiled underside of the thermal insulation element can also be realized in a variety of other ways, for example in a step shape, a radial toothing, an annular bead and much more.

In addition to optimizing the geometry of the underside of the thermal insulation element, smaller or smaller openings can additionally or alternatively be provided for subsequent grouting of any remaining cavities between the thermal insulation element and the concrete surface located underneath. Such openings can be closed with blind plugs and opened if necessary in order to subsequently fill any remaining cavity with a potting compound such as a potting mortar or a synthetic resin compound and thus establish a secure static connection, even if in individual cases a faulty execution when creating the support or the installation of the thermal insulation element had led to a poor connection. In addition, indicators can be provided on the thermal insulation element, which can be pushed up in the manner of a float and thereby indicate that the thermal insulation element has contact with the in-situ concrete underneath on its underside.

When installing the thermal insulation element in the already compacted, fresh concrete of the support underneath, during subsequent compacting and when pulling out the compacting tool from the through opening of the thermal insulation element, it may be advantageous if a defined pressure force is exerted on the thermal insulation element.

In addition to reinforcement bars, other rod-shaped reinforcement means for connecting the thermal insulation element to the building parts above and below can be used within the scope of the present invention, for example threaded rods, dowels or the like, since, as explained above, the connection between a support and a floor slab above it statically as a joint connection can be considered and the reinforcement at this point must therefore preferably have a constructive function.

Claims (12)

1. Thermal insulation element for thermal decoupling between load-bearing building parts to be constructed from concrete, preferably between a vertical building part, especially a pillar (1), and a horizontal building part located thereabove or therebelow, especially a ceiling (3), wherein the thermal insulation element (10) has a main body (11) which consists at least partly of a compressive-force-transmitting material and has an upper and a lower support face (12, 13) for vertical connection to the building parts (1, 2, 3),
   characterised in that
   the main body (11) of the thermal insulation element (10) consists at least partly of a compressive-force-transmitting and thermally insulating material, namely lightweight concrete, and has one or more bar-like reinforcing means, especially reinforcing bars (15), passing through the main body (11) and extending substantially vertically beyond the upper and lower support faces (12, 13), which reinforcing means consist of a fibre-reinforced composite material.
2. Thermal insulation element according to claim 1, wherein the reinforcing bars (15) are installed in sleeves which are embedded in the compressive-force-transmitting material.
3. Thermal insulation element according to claim 1 or 2, which has at least one through-opening (14) extending from the upper support face (12) to the lower support face (13), which through-opening is provided to allow passage of a compaction device for wet concrete.
4. Thermal insulation element according to claim 3, wherein the lower support face (13) has a three-dimensionally profiled surface, especially a surface that is domed or inclined funnel-like in the direction of the through-opening (14).
5. Thermal insulation element according to claim 3 or 4, having a preferably conical closure plug for subsequent closure of the through-opening (14), the closure plug preferably consisting of a thermally insulating material.
6. Thermal insulation element according to any one of the preceding claims, having a reinforcing hoop (17) arranged in the interior of the compressive-force-transmitting material.
7. Thermal insulation element according to any one of the preceding claims, which has an elasticity modulus lower than the elasticity modulus of standard concrete, preferably from 30 to 70 % of the elasticity modulus of standard concrete.
8. Thermal insulation element for thermal decoupling between load-bearing building parts to be constructed from concrete, preferably between a vertical building part, especially a pillar (1), and a horizontal building part located thereabove or therebelow, especially a ceiling or a floor slab (2, 3), wherein the thermal insulation element (10) has a main body (11) which consists at least partly of a compressive-force-transmitting material and has an upper and a lower support face (12, 13) for vertical connection to the building parts (1, 2, 3),
   characterised in that
   the main body (11) of the thermal insulation element (10) consists at least partly of a compressive-force-transmitting and thermally insulating material, namely lightweight concrete, and has one or more sleeves passing through the main body (11) vertically from the upper support face (12) to the lower support face (13), which sleeves are provided for the insertion of bar-like reinforcing means, especially reinforcing bars (15), extending substantially vertically beyond the upper and lower support faces (12, 13).
9. Load-bearing vertical building part constructed from concrete, especially a pillar (1), having a first support face (12, 13) for load-bearing attachment to a horizontal building part to be constructed from concrete thereabove or therebelow, especially a ceiling or a floor slab (2, 3), wherein the vertical building part has a reinforcement (6, 7) having one or more bar-like reinforcing means, especially reinforcing bars (7, 15), extending substantially vertically beyond the first support face (12, 13), wherein a region (4) of the vertical building part, which region adjoins the first support face (12, 13), is in the form of a thermal insulation element (10), according to any one of the preceding claims, for thermal decoupling between the vertical building part and the horizontal building part to be constructed thereabove or therebelow, wherein the region (4) forming the thermal insulation element (10) consists at least partly of a compressive-force-transmitting and thermally insulating material, namely lightweight concrete, and wherein the reinforcing means (7', 15') extending beyond the first support face (12, 13) consist of a fibre-reinforced composite material and extend through the first region (4) of the vertical building part, which first region forms the thermal insulation element (10), substantially vertically into an adjoining second region (1') in which the vertical building part has been constructed from reinforced standard concrete.
10. Method of constructing a vertical building part from concrete, especially a pillar (1), having a first support face (12, 13) for load-bearing attachment to a horizontal building part to be constructed from concrete thereabove or therebelow, especially a ceiling (3), wherein:

    - a first region (1') of the vertical building part (1) is constructed from reinforced standard concrete;

    - a second region (4) of the vertical building part (1), which second region is located between the first support face (12) and the first region (1'), is formed at least partly from a compressive-force-transmitting and thermally insulating material, namely lightweight concrete, in order to serve as thermal insulation element (10) for thermal decoupling between the vertical building part(1) and the horizontal building part (3) to be constructed thereabove or therebelow; and

    - in the second region (4) of the vertical building part, which second region forms the thermal insulation element (10), there are installed bar-like reinforcing means, especially reinforcing bars (7, 15) made of a fibre-reinforced composite material, which extend through the second region (4) of the vertical building part(1) substantially vertically into the adjoining first region (1') and beyond the first support face (12).
11. Method according to claim 10, wherein

    - for the first region (1') of the vertical building part, a reinforcement (6) and a formwork arranged around the reinforcement (6) are constructed;

    - wet standard concrete is introduced into the formwork up to the level of the first region (1') of the vertical building part (1);

    - in a first region of the formwork which corresponds to the second region (4) of the vertical building part (1), reinforcing bars (7) made of fibre-reinforced composite material are inserted; and

    - then the second region (4) of the vertical building part(1) is constructed by introducing wet lightweight concrete into the first region of the formwork.
12. Method according to claim 10, wherein
    - - for the first region (1') of the vertical building part (1), a reinforcement (6) and a formwork arranged around the reinforcement (6) are constructed;

    - wet standard concrete is introduced into the formwork up to the level of the first region (1') of the vertical building part (1); and

    - the second region (4) of the vertical building part (1) is formed by a thermal insulation element (10) according to any one of claims 1 to 8, which is inserted into the formwork.

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