Device and method for the thermal decoupling of concrete building parts

Abstract

In a load-bearing concrete vertical building part, particularly a support, with an upper support area for a load-transferring connection to a concrete horizontal building part thereabove, in which the vertical building part includes reinforcements with reinforcement rods extending essentially vertically beyond the upper support area, an upper section of the vertical building part abutting the upper support area is embodied as a thermal insulation element for the thermal decoupling of the vertical building part from the horizontal building. The upper section forming the thermal insulation element is made at least partially from a compressive load transferring and thermally insulating material, particularly light-weight concrete, and reinforcement rods extending beyond the upper support area are made from a fiber composite material, and extend through the upper section of the vertical building part forming the thermal insulation element essentially vertically to the lower section of the vertical building part located underneath thereof.

Claims

1. A load-bearing vertical building part (1), made from concrete, comprising a first section with a first support area (12, 13) for a load-transferring connection to a horizontal building part (2, 3) to be made from concrete located thereabove or therebelow, reinforcements (6, 7) with one or more rod-shaped reinforcement elements projecting essentially vertically beyond the first support area (12, 13), the first section (4) of the vertical building part comprises a thermal insulation element (10) for thermal decoupling of the vertical building part from the horizontal building part to be produced thereabove or therebelow, the first section (4) is formed of a light-weight concrete having a dry density of below 2000 kg/m3 and a thermal conductivity of between 0.2 and 1.6 W/(m.Math.K), and the rod-shaped reinforcement elements (7, 15) projecting beyond the first support area (12, 13) are made from a fiber composite material and essentially extend vertically through the first section (4) of the vertical building part, forming the thermal insulation element (10), to a second section (1) abutting thereat, in which the vertical building part is produced from reinforced concrete having a dry density of above 2000 kg/m.sup.3, and wherein a compressive load of the building parts above the first support area (12) is carried by the first section (4) without any integrated compression elements of higher compressive strength.

2. A thermal insulation element for the thermal decoupling of load bearing building parts to be created from concrete, the thermal insulation element (10) comprising a basic body (11) with an upper support area and a lower support area (12, 13) for vertical connection to building parts (1, 2, 3), the basic body (11) being made from a light-weight concrete having a dry density of below 2000 kg/m3 and a thermal conductivity of between 0.2 and 1.6 W/(m.Math.K) and being dimensioned such that when integrated into a building, the basic body (11) is adapted to carry a compressive load of the building parts above said upper support area (12) without any integrated compression elements of higher compressive strength in the basic body, and one or more rod-shaped reinforcement elements (15) penetrating the basic body (11) and extending essentially vertically beyond the upper and the lower support areas (12, 13).

3. The thermal insulation element according to claim 2, wherein the rod-shaped reinforcement elements comprise reinforcement rods (15) that are inserted in sheaths, which are embedded in the compressive force-transferring material.

4. The thermal insulation element according to claim 2, further comprising at least one penetrating opening (14) extending from the upper support area to the lower support area (12, 13), which is embodied for introducing a compacting device for fresh concrete.

5. The thermal insulation element according to claim 4, wherein the lower support area (13) has a three-dimensional profiled surface.

6. The thermal insulation element according to claim 5, wherein the lower support area has a surface declined or arched like a funnel in a direction of the penetrating opening (14).

7. The thermal insulation element according to claim 4, further comprising a plug for subsequent closing of the penetrating opening (14), with the plug being made from a thermally insulating material.

8. The thermal insulation element according to claim 2, further comprising a reinforcement bar (17) arranged inside of the compressive force-transferring material.

9. The thermal insulation element according to claim 2, wherein the basic body has a coefficient of elasticity which is lower than an elasticity module of standard concrete.

10. A thermal insulation element for the thermal decoupling of load-bearing building parts to be made from concrete, the thermal insulation element (10) comprising a basic body (11) with an upper support area and a lower support area (12, 13) for vertical connection to building parts (1, 2, 3), the basic body (11) being made from a light-weight concrete having a dry density of below 2000 kg/m3 and a thermal conductivity of between 0.2 and 1.6 W/(m.Math.K) and being dimensioned such that when integrated into a building, the basic body (11) is adapted to carry a compressive load of the building parts above said upper support area (12) without any integrated compression elements of higher compressive strength in the basic body, and one or more sheaths penetrating the basic body (11) vertically from the upper support area to the lower support area (12, 13), adapted for inserting rod-shaped reinforcement elements that extend essentially vertically beyond the upper and the lower support areas (12, 13).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional features, advantages, and characteristics of the present invention are explained in the following based on the figures and based on exemplary embodiments. Shown here are:

(2) FIG. 1 a section through a support made from concrete and building parts located above and below thereof,

(3) FIG. 2 an isometric view of a thermal insulation element according to the invention made from a compressive load-transferring material, particularly light-weight concrete,

(4) FIG. 3 a top view of the thermal insulation element of FIG. 2,

(5) FIG. 4 a vertical cross-section through the thermal insulation element along the sectional line C-C of FIG. 3,

(6) FIG. 5 a further development of the thermal insulation element of FIG. 2 in a side view,

(7) FIG. 6 a cross-section through the support of FIG. 1,

(8) FIG. 7 the reinforcement of the support of FIG. 1 with the thermal insulation element prior to the casing of the support being filled with cast-in-place concrete,

(9) FIG. 8 the support provided with a casing after being filled with concrete,

(10) FIG. 9 an enlarged section of FIG. 8, and

(11) FIG. 10 an alternative exemplary embodiment with a thermal insulation element arranged in the base section of a support.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(12) In a first exemplary embodiment shown in FIG. 1 a support 1 is provided, monolithically connected to a base plate 2 and a ceiling 3. The upper section 4 of the support is made from light-weight concrete, while the lower section 1 is made from standard cast-in-place concrete (standard concrete). The support 1 may for example have a clear height of 220 cm. The upper section thereof amounts to 10 cm. A thermal insulation layer 5 made from a highly insulating material is applied below the ceiling, with its thickness essentially being equivalent to at least the height of the upper section 4 of the support 1. For example, mineral insulation plates or excelsior multilayer boards may be installed as the thermal insulation layer 6.

(13) In order to prepare the building parts shown in FIG. 1, firstly the base plate 2 with the reinforcement 2 is cast in concrete in a conventional fashion. In order to connect the support 1 to the base plate, here reinforcement rods 2 project vertically upwards from the horizontal reinforcement 2 of the base plate 2. They are then connected to the reinforcement 6 made from construction steel and arranged inside the support 1. The reinforcement 6 comprises four vertical reinforcement rods 6 and a plurality of reinforcement bars 6 arranged distanced in the vertical direction and showing an approximately square layout. In the upper section 4, instead of reinforcement rods 6 made from construction steel, here four reinforcement rods 7 made from fiber composite are inserted, for example the fiber composite material distributed by the applicant under the tradename ComBAR. In the upper section 4 reinforcements surround the reinforcement rods 7, arranged perpendicular in reference thereto, for example a reinforcement bar 7 made from stainless steel. The reinforcement rods 7 project beyond the upper section 4 of the support in order to allow a monolithic connection to the ceiling 3 to be produced above thereof at a later time. Additionally, the reinforcement rods 7 also project from the upper section of the support, serving as the thermal insulation element, into the lower section 1 made from standard concrete.

(14) Then a casing (cf. FIG. 8) is erected around the reinforcement 6 and closed at all sides for the support 1. Subsequently cast-in-place concrete is inserted, namely up to the height of the lower section 1, thus in the exemplary embodiment to a height of approximately 210 cm. The cast-in-place concrete, here typical ready-to-use standard concrete provided on construction sites, is then compacted with an internal vibrator. When the cast-in-place concrete has set fresh light-weight concrete is filled into the casing provided in the upper section 4 located thereabove and also compacted. As soon as it has set, in a manner also known per se the production of the ceiling 3 can continue, with its reinforcement 3 being cast in cast-in-place concrete together with the reinforcement rods 7 projecting beyond the upper contact area of the support 1 and made from fiber composite material.

(15) Alternatively to producing the upper section 4 of the support 1, serving as the thermal insulation element, from a special light-weight cast-in-place concrete, here a prefabricated form part may also be installed as the thermal insulation element in the casing of the support. In this case the casing of the support is either filled through an opening in the form part with cast-in-place concrete or the casing is initially filled with cast-in-place concrete up to the elevation of the lower section 1 and the form part is then inserted from the top into the casing and impressed into the still fresh cast-in-place concrete of the support 1. Here it is beneficial to insert an internal vibrator through a central opening into the form part in order to subsequently compact the cast-in-place concrete in the connection area.

(16) FIGS. 2 to 4 show a thermal insulation element 10 comprising such a form part. It serves for the monolithic connection and for the load-transferring connection of a support 1 made from concrete, for example in the lower level of a building, to the basement ceiling 3 located thereabove. The thermal insulation element 10 has a cuboid base element 11 with a top 12 and a bottom 13, each serving as support areas for the basement ceiling and/or the end of the support 1 carrying it. A central penetrating opening 14 is located in the middle of the cuboid thermal insulation element 10, which extends from the top 12 to the bottom 13 of the thermal insulation element 11. Four reinforcement rods 15 made from fiber composite project through the basic body 11. The bottom 13 of the basic body has a three-dimensional profiling in the form of a recess 16 extending like a funnel in the direction of the penetrating opening 14. Inside the basic body 11, additionally a reinforcement rod 17 is embedded, which is arranged around the reinforcement rods 15 and provides additional stability for the thermal insulation element 10.

(17) The basic body 11 of the thermal insulation element 10 is made from light-weight concrete, which on the one hand has high compressive load stability and on the other hand has good thermal insulating features. Compared to concrete with a thermal conductivity of approx. 1.6 W/(m.Math.K), when using suitable light-weight concrete the thermal conductivity amounts to approx. 0.5 W/(m.Math.K), which is equivalent to an improvement by approx. 70%. The light-weight concrete used essentially comprises expanded clay, fine sand, preferably light-weight sand, flux agents, as well as stabilizers, preventing any separating or floating of the grain and improving the processing features.

(18) The compressive strength of the thermal insulation element is here sufficiently high to allow the statically planned utilization of the underlying support made from cast-in-place concrete, for example according to the compressive strength classification C25/30. Preferably the compressive strength of the thermal insulation element is at least equivalent to 1.5 times the value required by static loads. This achieves that even in case of potential faulty sections at the connection area of the thermal insulation element to the support, here safety reserves are given so that the thermal insulation element remains statically stable even in case of punctually higher stress.

(19) The reinforcement rods 15 crossing the basic body 11 of the thermal insulation element 10 in the vertical direction serve primarily as tensile rods for transferring potentially arising tensile forces. The reinforcing rods 15 may be encased in concrete during the production of the thermal insulation element 10 in the light-weight concrete of the cuboid basic body 11. Alternatively, it is possible for an easier production of the thermal insulation element to install sheaths during the production as a type of dead casing, through which the reinforcement rods 15 are inserted after the curing of the light-weight concrete element 11.

(20) In the exemplary embodiment, the reinforcement rods 15 themselves are made from a fibrous composite, which comprises fiberglass aligned in the direction of force or a synthetic resin matrix. Such a fiberglass reinforcement rod have an extremely low thermal conductivity, which is up to 100 times lower than the one of concrete steel, and thus it is ideally suitable for the application in the thermal insulation element. Alternatively, reinforcement rods comprising stainless steel may be used as well within the scope of the present invention, particularly when using the above-mentioned sheaths as dead casings.

(21) Without limiting the invention thereto, the dimensions of the reinforcement rods 15 amount in the exemplary embodiment to a diameter of 16 mm with a length of 930 mm. The arrangement of the reinforcement rods 15 in reference to the base area of the basic body 11 is selected slightly outside the primary diagonal. The reason for this is given here in that in a support 1, in which the reinforcement rods 15 of the thermal insulation element 10 are installed, the reinforcement rods 6 of the support 1 are already located in the corners.

(22) The reinforcement rod 17 comprises a stainless steel bent to form a ring which is welded to the connection site. The reinforcement rod 17 shows a diameter of approx. 200 mm with a material thickness of 8 mm to 10 mm.

(23) In the exemplary embodiment the basic body 11 of the thermal insulation element 10 has a length of 250250 mm at the edges. The height amounts to 100 mm and thus it is equivalent to the common thickness of a subsequently applied thermal insulation layer. As discernible primarily in FIG. 4, the penetrating opening extends in a slightly conical fashion, with here the penetrating opening 14 tapering from an upper dimension of 70 mm to a lower dimension of 65 mm. The penetrating opening can also be easily closed via an appropriate, also slightly conical plug (not shown).

(24) FIG. 5 shows the thermal insulation element in a side view, with additional circumferential seals 18 being applied at the basic body 11. The seals 18 may be embodied as rubber lips or conventional sealing tape, for example. They serve to seal the basic body 11 of the thermal insulation element 10 tightly at the edges towards a casing for the support to be constructed underneath thereof, in order to prevent any rising of concrete or the penetration of air.

(25) FIG. 6 shows an installation situation of the thermal insulation element in reference to a support 1. The cross-section shown here extends underneath the basic body 11 of the thermal insulation element 10. The support 1 made from cast-in-place concrete shows reinforcements with four vertical reinforcing rods 6 arranged in the corners of the support 1 and a plurality of reinforcement bars 6 extending horizontally about the reinforcement rods 6 and embodied in an approximately square fashion. The reinforcing rods 15 of the thermal insulation element 10 are each located slightly offset next to the reinforcing rods 6 of the support 1. The sectional line B-B indicated in FIG. 6 is equivalent to the progression of the line of the longitudinal cross-section through the support reinforcement shown in FIG. 7.

(26) FIG. 7 shows the reinforcement of the support 1 together with the thermal insulation element 10 in a longitudinal cross-section. The progression of the section is here equivalent to the sectional line B-B of FIG. 6. The reinforcement of the support 1 comprises four vertical reinforcement rods 6 arranged in the corners of the support, which for example may be embodied from construction steel with the rods showing a diameter of 28 mm at a length of 2000 mm, as well as a plurality of reinforcement bars 6 arranged circumferential about the reinforcement rods 6 showing an approximately square layout. The thermal insulation element 10 is located above the reinforcement of the support, with its reinforcement rods 15 projecting downwards into the support reinforcement.

(27) The reinforcement content of the support 1 amounts to approximately 3-4%. At a typical thermal conductivity value of construction steel of approx. 50 W/(m.Math.K) in reference to concrete with 1.6 W/(m.Math.K) it contributes approximately to half the total thermal conductivity of the support. By the use of the combination of light-weight concrete and fiberglass reinforcement in the area of the thermal insulation element 10 the thermal conductivity between the support 1 and the ceiling 3 can therefore be reduced by approx. 90% in reference to a direct monolithic connection.

(28) In order to prepare the support 1, as shown in FIG. 8 in the upper half, a casing 19 is installed about the support reinforcement 6, 6 and the lower section 1 is filled with cast-in-place concrete. It is compacted in a conventional fashion with an internal vibrator. Subsequently the thermal insulation element 10 is inserted into the casing 19 from above and its reinforcement rods 15 are pressed into the still liquid cast-in-place concrete. The basic body 11 is compressed to the fresh cast-in-place concrete until the liquid concrete slightly rises upwards in the penetrating opening 14 such that it is ensured that no more air gap is given between the concrete of the support 1 and the basic body 11 of the thermal insulation element 10. Subsequently the vibration head of a concrete vibrator is inserted through the penetrating opening 14 into the fresh cast-in-place concrete located underneath in order to compact it once more. When inserting the vibration head the thermal insulation element 10 can be slightly raised by the volume of the concrete displaced by the vibration head. When pulling out the vibration head it must therefore be ensured that the thermal insulation element 10 lowers again by said volume in that the thermal insulation element 10 is pushed downwards accordingly when the vibrator is pulled out. Here, the circumferential seal 18 prevents air from penetrating between the casing and the thermal insulation element or the thermal insulation element 10 can tilt inside the casing. FIG. 9 displays the section marked detail D around one of the seals 18 once more in an enlarged fashion.

(29) The subsequent compacting of the still liquid fresh concrete via the penetrating opening 14 of the thermal insulation element 10 leads to a close connection of the thermal insulation element 10 with the cast-in-place concrete located underneath. In particular, elevations due to the formation of bubbles or sedimentation in the fresh concrete are prevented between the thermal insulation element 10 and the support 1. This is promoted primarily also by the conically extending profiling at the bottom of the basic body 11, based on which the rising air bubbles and/or the surface of the separated cement water can collect primarily in the central area of the penetrating opening 14.

(30) After the support was formed from concrete and the subsequent compacting via the penetrating opening 14 any remnants of concrete remaining in the penetrating opening 14 are removed. Subsequently the penetrating opening 14 is closed via a conical plug (not shown). The closing plug may comprise an insulating material, such as polystyrene or the like, and serves to prevent the penetration of cast-in-place concrete into the penetration opening 14 when subsequently the ceiling 3 is produced. This way potential heat bridges are avoided due to a concrete filling in the penetrating opening 14. Subsequently, above the thermal insulation element 10 the ceiling 3 located thereabove is produced in a common fashion.

(31) Except for the purpose of compacting and/or subsequent compacting the penetrating opening 14 can also be used as an inlet for filling the casing for the support 1 with cast-in-place concrete. In this case, the thermal insulation element is inserted into the still empty casing of the support 1 and perhaps the reinforcement rods 15 are connected to the support reinforcement. Subsequently fresh concrete is filled via the penetrating opening 14 of the thermal insulation element into the casing and then compacted by a vibration head of an internal vibrator being inserted through the penetrating opening 14. Here, too the compacting of fresh concrete against the bottom of the thermal insulation element occurs from the top through the penetrating opening 14. Alternatively the support 1 can also be prepared from self-compacting concrete or the compacting of the support can occur by an external vibrator, of course. Therefore in the latter two cases the penetrating opening 14 serves only as an inlet opening.

(32) In addition to the installation in the upper area of a support, an installation in the base of a support is possible as well. Such an arrangement is shown in FIG. 10 in an alternative exemplary embodiment. The support 1 is here arranged between the bottom plate 2 and the upper ceiling 3. In the base area of the support 1 a thermal insulation element 10 according to the invention is installed, with its reinforcement rods 15 projecting from the base plate 2 to the upper area of the support 1, and here being connected to the reinforcement 6 of the support 1. A thermal insulation layer 5 made from insulation plates of prior art is applied in this case on the top of the bottom plate 2.

(33) The production can occur such that the thermal insulation element 10 is connected to its reinforcement 2 before the base plate 2 is cast from concrete. The base plate 2 is then cast from cast-in-place concrete such that the concrete rises from the bottom towards the thermal insulation element 10. In order to yield a good connection free from clear space the cast-in-place concrete can in turn be compacted with a vibration tool passed through the central penetrating opening. After curing the reinforcement 6 of the support is produced and connected to the reinforcement rods 15 of the thermal insulation element. Subsequently the casing for the support 1 is constructed around the thermal insulation element 10 and then the support 1 is cast and compacted from cast-in-place concrete in a conventional fashion.

(34) The thermal insulation element according to the invention itself may be adjusted in its dimensions to the construction part located underneath and/or above. In particular, thermal insulation elements may be adjusted to the typical cross-sections of supports with round, square, or rectangular cross-sections. Typical dimensions of round supports are diameters of 24 and 30 cm, and/or supports with rectangular cross-sections of 2525 cm and 3030 cm. Thermal insulation elements with such a geometry may also be combined arbitrarily to form greater supports or load bearing walls

(35) The thermal insulation elements described here are particularly suited for the use in connecting links, such as wall supports with low fixing moments. Additionally, the use of load bearing exterior walls is also possible by installing thermal insulation elements at a suitable distance from each other and any perhaps remaining gaps between the individual thermal insulation elements can be filled with insulation material that is not load bearing.

(36) The geometric design of the profiled bottom of the thermal insulation element may also be realized in many other ways, in addition to the conical shape shown here, for example a stepped form, a radial gearing, an annular bead, and so forth.

(37) In addition to optimizing the geometry of the bottom of the thermal insulation element more and/or alternatively smaller openings may be provided for subsequently casting potentially remaining cavities between the thermal insulation element and the concrete area located underneath. Such openings may be closed with plugs and opened when needed in order to subsequently fill any potentially remaining cavities via a casting mass, such as casting mortar or a synthetic resin, and thus to generate a secure static connection, although in the individual case a faulty embodiment during the preparation of the support and/or the installation of the thermal insulation element had resulted in a flawed connection. Additionally, indicators may be provided at the thermal insulation element which can be pressed upwards like a float and here indicate that the thermal insulation element with its bottom is in contact with the cast-in-place concrete located underneath thereof.

(38) During the installation of the thermal insulation element into already compacted, fresh concrete of the support located underneath, during the subsequent re-compacting, and when the compacting tool being pulled out of the penetrating opening of the thermal insulation element it may be advantageous if a defined compression is applied upon the thermal insulation element.

(39) In addition to the reinforcement rods, within the scope of the present invention other rod-shaped reinforcing elements may be used for connecting the thermal insulation elements to the building parts located above and below, for example threaded rods, dowels, and the like, because as explained above the connection between a support and a ceiling located thereabove can be considered a link with regards to statics and the reinforcement at this point must therefore fulfill a constructive function.