Description
The invention relates to a connecting anchor of the genus specified in the preamble to claim 1 and to a multi-layer concrete slab of the genus specified in the preamble toclaim 12.
US 3,996,713 A describes a connecting anchor for multi-layer concrete slabs, so-
called sandwich slabs, that is configured substantially as a rectangular plate.
The connecting anchor has openings adjacent to the two longitudinal sides through which anchoring pins can be passed.
US 4,624,089 A discloses a connecting anchor for use in sandwich slabs that has bent end portions on one longitudinal side through which anchoring pins are passed.
EP 0 381 000 Ai discloses a multi-layer concrete slab that is bordered by profiles at its outer edges.
The connecting anchors, the ends of which are embedded in the concrete slabs, are configured as flat plates.
BE 898 653 A shows a concrete slab having a generic connecting anchor.
On its end portions the connecting anchor has lugs that are bent out of the plane of the con- necting anchor.
FR 2 987 467 Al discloses plate-shaped connecting anchors to which anchoring el-
ements are fitted.
DE 198 48 228 A1 shows connecting anchors that are bent from wire.
The object of the invention is to create a connecting anchor with improved charac-
teristics for multi-layer concrete slabs.
A further object of the invention is to specify multi-layer concrete slabs with an advantageous structure.
The object relating to the connecting anchor is achieved by a connecting anchor having the features of claim 1. The object relating to the multi-layer concrete slab is achieved by a concrete slab having the features of claim 12.
To improve the anchoring of the connecting anchor in the surrounding concrete, claim 1 provides for the plate to have an end portion adjacent to at least one longi- tudinal side in which the plate is bent out of the plate plane of the plate in a first direction of bending at a first bending point and bent in a second direction of bend- ing running in the opposite direction to the first direction of bending at a second bending point.
The fact that the plate is bent out of the plate plane and then back in the direction of the plate plane results in a zigzag-shaped plate.
This forms indenta- tions in the direction of a median plane located between the longitudinal sides of the plate on either side of the plate.
Embedding the connecting anchor in the con- crete of a sandwich slab results in indentations in the direction of the thermal insu-
lation layer.
This achieves improved anchoring of the connecting anchor and im- proved transmission of force between the concrete layers of the concrete slab.
Due to the second bending point at which the plate is bent in the second direction of bending, it is possible to keep the total thickness of the plate small so that the slab can be inserted easily into gaps between any reinforcement present in a layer of
— concrete.
The configuration of the at least one end portion with a first and a second bending point is advantageous for textile-reinforced concrete layers in particular.
The first and second bending points are provided in particular when the thickness of the con-
— crete layer into which the connecting anchor projects is comparatively small.
The thickness of the concrete layer is preferably less than 5cm.
The at least one end portion of the plate has a wave-shaped profile formed by a plurality of bending points.
At least four bending points per end portion is consid-
ered to be particularly advantageous.
The wave-shaped profile is created, in particu- lar, by arranging the bending points the same distance from the plate plane.
In a particularly advantageous configuration, the plate has an end portion having at least a first bending point and a second bending point adjacent to each longitudinal side.
End portions with a wave-shaped profile are preferably provided on both longitudi- nal sides. The plate preferably has at least one recess on the at least one longitudinal side. The base of the recess is advantageously rounded, preferably configured as a con- tinuous radius. This allows tensions at the base of the recess to be minimised. The at least one recess preferably separates fingers of the plate from one another. At least two fingers, separated from one another by a recess, are particularly prefera- bly provided on each longitudinal side of the plate. To improve the anchoring of the connecting anchor in the surrounding concrete, the plate preferably has at least one opening that passes through the plate on the at least one longitudinal side. The at least one opening is advantageously arranged in a finger. Each finger particularly preferably has at least two openings. The two openings in each finger are advantageously offset in relation to each other both in the longitudinal and in the vertical direction of the plate. The at least one opening advantageously passes through the region of the end portion that has the at least one bending point. The at least one opening is advantageously arranged at least partially between two bending points. The at least one opening achieves improved anchoring of the connecting anchor, in particular in textile-reinforced concrete lay-
ers. If the concrete layer contains reinforcing bars rather than textile reinforcement, the at least one opening may serve to receive a reinforcing bar that provides addi- tional reinforcement for the plate. At least two receivers arranged at different distances from the second longitudinal side are advantageously arranged on the plate. A limiting element for limiting the insertion depth of the connecting anchor in the thermal insulation layer is held de- tachably in one of the at least two receivers. Alternatively, the limiting element may be arranged in one of the at least two receivers by fixing it detachably in the receiv-
er. The choice of receiver predetermines the insertion depth of the connecting an- chor in the thermal insulation layer. Providing a plurality of receivers at different distances from the second longitudinal side makes it possible to adjust the insertion depth of the connecting anchor in the thermal insulation layer.
In the production of the concrete slab one of the concrete layers, preferably a sec- ond concrete layer that forms the facing shell, is cast first.
The thermal insulation layer is then placed on this concrete layer.
The at least one connecting anchor is pressed through the thermal insulation layer into the as yet uncured concrete layer.
The connecting anchor is pressed into the thermal insulation layer until a contact portion of the limiting element abuts the top of the thermal insulation layer, thereby hampering or preventing the further insertion of the connecting anchor into the thermal insulation layer and the cast first concrete layer.
Once all the connecting anchors have been fitted, the second concrete layer is then cast onto the thermal insulation layer, and the portions of the connecting anchor projecting beyond the thermal insulation layer are cast into this concrete layer.
In the case of thin concrete layers, in particular, this adjustable insertion depth makes it possible to ensure that the connecting anchor cannot be pressed as far as the outside of the second con- crete layer.
This ensures that the connecting anchor is not visible from the outside of the concrete slab.
In an advantageous configuration, the at least one receiver is arranged in a trans- verse side of the plate.
The limiting element can preferably be inserted or clipped into the receiver.
In an alternative configuration the at least one receiver is ar-
ranged between the transverse sides of the plate.
The receivers arranged between the transverse sides of the plate are advantageously closed around their entire cir- cumference.
The limiting element is preferably configured in two parts to enable the limiting element to be fitted easily into the at least one receiver arranged between the transverse sides of the plate.
This means that the portions can be arranged in the receiver from opposing sides of the receiver and then connected to one another.
One plate may have both receivers on one transverse side and receivers between the transverse sides of the plate.
In an advantageous configuration the receivers are arranged mirror symmetrically in relation to a median plane of the plate than runs centrally between the longitudinal sides.
As a result, the limiting element can be used both to limit the insertion depth in the first concrete layer and to limit the insertion depth in the second concrete layer.
In a particularly preferred arrangement the plate is configured mirror sym- metrically in relation to the median plane.
This obviates the need to consider the orientation of the plate when arranging it in a thermal insulation layer and a con- crete layer. The configuration of the connecting anchor is advantageously adjusted to ensure 5 low transfer of heat between the concrete layers. The form of the portion of the plate provided to be arranged in the thermal insulation layer advantageously devi- ates from the rectangular. One longitudinal side of the connecting anchor is prefer- ably shorter than the other longitudinal side. The shorter longitudinal side is prefer- ably arranged in the shallower concrete layer, advantageously in the facing shell. This is in particular the second concrete layer. At least one portion, in particular the portion to be arranged within the thermal insulation layer, of at least one transverse side advantageously meets one of the longitudinal sides at an angle of less than
90°. In an advantageous configuration the region of the connecting anchor provided to be arranged in the thermal insulation layer may have at least one further recess. This at least one further recess reduces heat transfer from the first to the second longitudinal side. In a multi-layer concrete slab the concrete slab comprises a first concrete layer, a second concrete layer, a thermal insulation layer arranged between the concrete layers and at least one connecting anchor. The connecting anchor comprises a plate that has a first and a second longitudinal side. The first longitudinal side is arranged in the first concrete layer and the second longitudinal layer is arranged in the sec- ond concrete layer. The plate has a first transverse side and a second transverse side that extend from the first concrete layer through the thermal insulation layer into the second concrete layer. Adjacent to at least one longitudinal side the plate has an end portion that is arranged in one of the concrete layers and in which the plate is bent out of the plate pane in a first direction of bending at a first bending point and is bent in a second direction of bending opposite the first direction of bending at a second bending point. The at least two bending points in the end portion that is arranged in one of the concrete layers results in improved anchoring of the end portion in the concrete.
The concrete slab is preferably a so-called sandwich plate in which the two concrete layers are arranged directly on the two opposing flat sides of the thermal insulation layer and connected permanently to it. The plate advantageously has at least two receivers that are arranged at different distances from a second longitudinal side of the plate, a limiting element with a con- tact portion that abuts the thermal insulation layer being arranged in one of the receivers. The fact that the plate has at least two receivers means that the insertion depth of the connecting anchor in the thermal insulation layer and in one of the concrete layers can be adjusted easily. By arranging the limiting element in the receiver pro- vided it is possible to ensure a desired insertion depth. Where a plurality of connect- ing anchors is provided for one concrete slab it is possible to ensure that all the connecting anchors project into the concrete layer by the same amount. In this ar- rangement, all the limiting elements in the connecting anchors are arranged in re- ceivers in the plate and are the same distance from the second longitudinal side of the plate. This achieves a uniform insertion depth of the plate in the thermal insula- tion layer. On the at least one longitudinal side the plate advantageously has at least one re- cess that separates two fingers of the plate from one another. These fingers project into one of the concrete layers. A base of the recess is arranged in the thermal insu- lation layer. Arranging the base of the recess in the thermal insulation layer results in reduced heat input into the concrete layer into which the fingers project. This in turn improves thermal insulation. Arranging the base of the recess in the thermal insulation layer results in a larger plate cross section in the thermal insulation layer, thereby achieving adequate stability of the plate and allowing high forces to be transmitted between the concrete layers. Embodiments of the invention are described below with reference to the drawings.
Fig. 1 shows a schematic sectional view of a concrete slab in the region of a connecting anchor.
Fig. 2 shows a side view of a plate of the connecting anchor of the concrete slab from Fig. 1.
Fig. 3 shows a side view of the plate from Fig. 3 in the direction of arrow III in Fig. 2.
Fig. 4 shows a side view of a limiting element.
Fig. 5 shows a side view of the limiting element in the direction of arrow V in
Fig. 4.
Fig. 6 shows a plan view of the limiting element in the direction of arrow VI in Fig. 4.
Fig. 7 shows a schematic sectional view of an arrangement comprising a thermal insulating layer, a first concrete layer and a thermal insulation layer of a concrete slab before the connecting anchor is fitted in the thermal insulation layer and the first concrete layer.
Fig. 8 shows a plan view of the connecting anchor, the thermal insulation layer and the first concrete layer from Fig. 7 in the direction of arrow VIII in Fig. 7 after the connecting anchor is fitted in the thermal insu- lation layer and the concrete layer.
Fig. 9 shows a schematic sectional view of a detail of an embodiment of a connecting anchor in a thermal insulation layer and a first concrete layer.
Fig. 10 shows a side view of an embodiment of a plate of a connecting an- chor.
Fig. 11 shows a representation of a two-part limiting element in side view.
Fig. 12 shows the limiting element from Fig. 11 in a side view in the direction of arrow XII in Fig. 11.
Fig. 13 shows a top view of the limiting element in the direction of arrow XIII in Fig. 11.
Fig. 14 shows a schematic sectional view of an embodiment of an arrange- ment comprising a connecting anchor, a thermal insulation layer and a first concrete layer of a concrete slab before the connecting anchor is fitted in the thermal insulation layer and the first concrete layer.
Fig. 15 shows a side view of an embodiment of a limiting element.
Fig. 16 shows a side view of the limiting element from Fig. 15 in the direction of arrow XVI in Fig. 15.
Fig. 17 shows a side view of the limiting element from Fig. 15 in the direction of arrow XVII in Fig. 15.
Fig. 18 shows a plan view of a connecting anchor with the limiting element from Figs. 15 to 17 in a thermal insulation layer.
Fig. 19 shows a side view of the connecting anchor from Fig. 18 in a thermal insulation layer and a concrete layer. Figs. 20 to 23 show embodiments of concrete slabs with different designs of con- necting anchor.
Fig. 24 shows a further embodiment of a plate of a connecting anchor.
Fig. 24a shows the region of the receivers in the plate from Fig. 24 in an en- larged detail view. Figs. 25 to 29 show further embodiments of plates for connecting anchors.
Fig. 1 shows a detail of a concrete slab 1 in schematic form.
The concrete slab 1 has a multi-layer configuration.
The concrete slab 1 comprises a first concrete layer 11, which is advantageously a load-bearing layer, a second concrete layer 12, which in particular takes the form a facing shell, and a thermal insulation layer 2 arranged between the first concrete layer 11 and the second concrete layer 12. At least one connecting anchor 3 is provided to transmit forces through the thermal insulation layer 2 between the first concrete layer 11 and the second concrete layer 12. A plu- rality of connecting anchors 3, where necessary in combination with needle-shaped — connecting anchors (not shown) or further types of connecting anchor, are prefera- bly distributed in a predetermined arrangement throughout the concrete slab 1. The connecting anchor 3 comprises a plate 4. In the embodiment, the plate 4 has an approximately rectangular form.
A differently shaped plate 4 may also be advan- —tageous.
The plate 4 has a first longitudinal side 5 that is arranged in the first con- crete layer 11 and a second, opposing longitudinal side 6 that is arranged in the second concrete layer 12. The two longitudinal sides 5 and 6 are connected to one another by transverse sides 7 and 8. The transverse sides 7 and 8 extend from the first concrete layer 11 through the thermal insulation layer 2 into the second con- crete layer 12. The plate 4 has a notional median plane 31 that runs centrally between the longitu- dinal sides 5 and 6. In the embodiment, the plate 4 is configured mirror symmetri- cally in relation to the median plane 31. The plate 4 has a plurality of receivers 14 on its transverse sides 7 and 8. In the embodiment, five receivers 14 are provided on each transverse side 7, 8. The receivers 14 are approximately U-shaped.
In the embodiment, a limiting element 15 is arranged in the receivers 14 closest to the second longitudinal side 6 on each of the transverse sides 7 and 8. During produc- tion of the concrete slab 1, the limiting element 15, which is described in greater detail below, limits the insertion depth t of the connecting anchor in the composite element comprising the thermal insulation layer 2 and the second concrete layer 12. The thermal insulation layer 2 has a thickness ki.
The plate 4 has a plurality of recesses 10 on each longitudinal side 5 and 6. In the embodiment, four recesses 10 are provided on each longitudinal side 5 and 6. The recesses are slot-shaped in configuration and open towards the adjoining longitudi- nal side 5 and 6. The recesses 10 have a base 30 that is advantageously curved. In the embodiment, the base 30 is shaped like part of a circle. As shown in Fig. 1, the bases 30 of the recesses 10 adjacent to the second longitudinal side 6 are arranged in the thermal insulation layer 2. The bases 30 that are arranged adjacent to the first longitudinal side 5 run within the first concrete layer 11.
Fig. 2 shows the plate 4 of the connecting anchor 3 in detail. The plate 4 is prefera- bly made from a metal plate of constant thickness. The plate 4 is preferably a bent plate part from which openings, notches, recesses etc. have been stamped and which has end portions 19 and 20 that have been bent into the desired form. The plate 4 may be made of steel, for example, preferably stainless steel. A design using another material may, however, also be advantageous. As shown in Fig. 2, the plate 4 has a length d measured parallel to the median plane 31 and a height h measured perpendicular to the medial plane 31. The height h corresponds to at least the thickness k of the thermal insulation layer 2 (see Fig. 1) plus double the minimum bond depth by which the connecting anchor 3 must project into the concrete layers 11 and 12 in order to ensure sufficient introduction of force into the concrete layers 11 and 12. As also shown in Fig. 2, the recesses 10 separate individual fingers 13 of the plate 4 from one another. In the embodiment, four recesses 10 and five fingers 1 are pro- vided on each longitudinal side 5, 6. The number of fingers 13 and recesses 10 can be selected to suit the specific application. As also shown in Fig. 2, the recesses 10 have a width g. The fingers 13 have a width f. The width f of the fingers 13 is ad- vantageously 0.5 to 3 times the width g of the recesses 10. As also shown in Fig. 2, openings 9 are provided in the end portions 19, 20. Each finger 13 advantageously has at least one opening 9 and preferably at least two openings 9. In the embodiment, five receivers 14 are arranged on each transverse side 7, 8. The receivers 14 on each transverse side 7, 8 are positioned different distances from the second longitudinal side 6. The receiver 14 closest to longitudinal side 6 is positioned a distance a; from longitudinal side 6. The subsequent receiver 14 is ar- ranged a distance a? from longitudinal side 6 that is somewhat more than the width of a receiver 14 greater than the distance ai. The further receivers 14 are arranged at distances as, a4 and as from longitudinal side 6. In the embodiment, distances ai to asare selected so as to result in constant distances between adjacent receivers
14. However, different distances between adjacent receivers 14 may also be advan- tageous. Distances ai to as correspond to the insertion depths t (see Fig. 1) that can be set by arranging a limiting element 15 in the appropriate receivers 14. — Fig. 3 shows the configuration of the end portions 19 and 20 in detail. A first bend- ing point 21 at which the plate 4 is bent out of its plate plane 27 in a first direction of bending 25 is provided in each end portion 19, 20. The plate 4 is bent in a direc- tion of bending 26 opposite the direction of bending 25 at a second bending point
22. The plate 4 is bent again in direction of bending 25 at a third bending point 23 and then in direction of bending 26 at a fourth bending point 24. The plate plane 27 runs centrally between a first flat side 28 and a second flat side 29 of the plate 4 in the flat region of the plate 4 between the end portions 19 and 20. Bending points 22, 23 and 24 are all positioned the same distance from the plate plane 27. In the embodiment, the plate 4 is bent by 90° at each of bending points 22, 23 and 24. — This results in a zigzag- or wave-shaped course of the plate 4 at the end portions 19 and 20. As is also shown in Fig. 3, the plate 4 has a constant thickness p. In the embodiment, the bending points 21 to 24 run parallel to the longitudinal sides 5, 6. Figs. 4 to 6 show a first embodiment of a limiting element 15. The limiting element 15 may, for example, be a bent, reshaped portion of wire. The limiting element 15 has a contact portion 16 that connects two feet 17 to one another. In the embodi- ment, the feet 17 run at right angles to the contact portion 16. The contact portion 16 takes the form of a cross web. Configured on each foot 17 is a point 18 by means of which the limiting element 15 can be pressed into the thermal insulating — layer 2.
Fig. 7 shows the connecting anchor 3 during production of a concrete slab 1. The connecting anchor 3 has a limiting element 15 on each transverse side 7 and 8. The two limiting elements 15 are arranged in receivers 14 that are positioned the same distance from the second longitudinal side 6. A second concrete layer 12 of the con- crete slab 1 has already been cast. A thermal insulating layer 2 is placed on the second concrete layer 12. The connecting anchor 3 is then pushed through the thermal insulating layer 2 and into the as yet uncured concrete of the second con- crete layer 12 until the contact portions 16 of the limiting elements 15 abut the top of the thermal insulation layer 2. The contact portions 16 may be pushed slightly into the thermal insulation layer 3 in the process.
Fig. 8 shows the arrangement after the connecting anchor 3 has been pressed in. The contact portions 16 of the two limiting elements 15 abut the thermal insulation layer 2. The plate 4 projects out of the thermal insulation layer 2. The feet 17 and points 18 are arranged within the thermal insulation layer 2.
Fig. 9 shows an embodiment of a connecting anchor 3 that is arranged in a second concrete layer 12 and in a thermal insulation layer 2. In the embodiment illustrated the limiting element 15 is arranged in the receiver 14 positioned a distance as from the second longitudinal side 6. In the embodiment according to Fig. 9, the thermal insulation layer 2 has a thickness ko that is greater than the thickness ki of the thermal insulation layer 2 in the embodiment according to Fig. 1. By arranging the limiting element 15 in different receivers 14 it is possible to adjust the insertion depth t to the thickness k of the thermal insulation layer 2 such that only the fingers 13 project into the second concrete layer 12 and the bases 30 of the recesses 10 are arranged within the thermal insulation layer 2. By selecting the insertion depth t appropriately it is also possible to ensure that the connecting anchor 3 is unable to reach the outside of the second concrete layer 12 and thus is not visible in the fin- ished concrete slab 1.
Fig. 10 shows a further embodiment of a plate 4 of a connecting anchor 3. The plate 4 has receivers 34 for limiting elements 15 arranged between the transverse sides 7 and 8. In the embodiment, the receivers 34 take the form of openings that are closed around their entire circumferences. The receivers 34 may, for example, be circular receivers 34. In the embodiment according to Fig. 10, two rows each comprising five receivers 34 are arranged spaced apart from one another by a dis- tance m. The distance m between the rows is advantageously at least 20% of the length d of the plate 4. In the embodiment, each row of receivers 34 comprises five receivers 34 each positioned at a different distance a; to as from the second longi- tudinal side 6. Another number of rows of receivers 34 may also be advantageous. In addition to the receivers 34, five receivers 14 are also arranged on either trans- — verse side 7, 8. These receivers 14 are positioned the same distances a; to as from the second longitudinal side 6 as the receivers 34. As a result, it is possible to ar- range up to four limiting elements 15 on the plate 4 for each insertion depth t. Figs. 11 to 13 show an embodiment of a limiting element 15 that is provided to be arranged in receivers 34. The limiting element 15 is configured in two parts. The contact portion 16 is divided into two portions 16.1 and 16.2. The contact portion 16 takes the form of a web. The two portions 16.1 and 16.2 can be connected to one another. In the embodiment this is achieved by means of a plug-in connection comprising a pin 35 on portion 16.2 and a recess 36 in portion 16.1. In all other respects, the configuration of the limiting element 15 corresponds to that of the limiting element 15 shown in Figs. 4 to 6.
Fig. 14 shows the arrangement of limiting elements in receivers 34 before the con- necting anchor 3 is fitted in the second concrete layer 12 and the thermal insulation — layer 2. Figs. 15 to 17 show a further embodiment of a limiting element 15. The limiting element from Figs. 15 to 17 has a contact portion 16 that takes the form of a plate. Arranged on the limiting element 15 is a foot 17 with a point 18 that extends per- — pendicular from the plane of the contact portion 16. As shown in Fig. 17 in particu- lar, the contact portion 16 has a slit 37. Arranged at the end of this slit 37 is a web 38 that is circular in shape and has a diameter somewhat greater than the thickness of the plate that forms the contact portion 16. As a result, the web 38 projects slightly beyond the plane of the contact portion 16. The web 38 of the limiting ele- ment 15 can be glued into a receiver 14 of a plate 4. All the limiting elements 15 are preferably produced as plastic injection moulded parts.
Fig. 8 shows two limiting elements 15 in the configuration according to Figs. 15 and 17 on a plate 4 that is inserted into a thermal insulation layer 2 and a second con- crete layer 12 (not shown) located beneath it. This arrangement is shown with the second concrete layer 12 in Fig. 19. Fig. 19 shows the arrangement of the web 38 inthe receiver 14 and the arrangement of the contact portion 16 on the thermal insulation layer 2. As shown in Fig. 19, the thermal insulation layer 2 has a first side 32 that faces the first concrete layer 11 (not shown in Fig, 19) and a second side 33 that faces the second concrete layer 12. The contact portion 16 is located on the second side 32. The feet 17 and points 18 project into the thermal insulation layer
2. As also shown in Fig. 19, the bases 30 of the recesses 14 run along the second longitudinal side 6 within the thermal insulation layer 2.
Fig. 20 shows a further embodiment of a multi-layer concrete slab 1. The concrete slab comprises a first concrete layer 11 and a second concrete layer 12 in which reinforcing bars 39 are arranged. The concrete layers 11 and 12 are connected to one another by connecting anchors 3, one of which is shown in Fig. 20. In the em- bodiment, the reinforcing bars 39 are arranged in a grid parallel and perpendicular to the plane of the plate 4. The reinforcing bars 39 that run parallel to the plane of the plate 4 run at the height of the fingers 13. The reinforcing bars 39 that run per- — pendicular to the plane of the plate 4 run through recesses 10 between adjacent fingers 13. As also shown in Fig. 20, in the embodiment according to Fig. 20 each finger 13 has four openings. It is also possible for individual reinforcing bars to be inserted through individual openings 9 in the fingers 13. The plate 4 according to Fig. 20 also differs from the preceding embodiments in that the basic form of portion of the plate 4 arranged in the thermal insulation layer 2 deviates from the rectangular. The portion of the plate 4 that projects into the sec- ond concrete layer 12 is narrower than the portion that projects into the first con- crete layer 11. The width bi of the end portion 19 of the plate 4 that projects into the first concrete layer 11 is greater than the width b; of the end portion 20 that projects into the second concrete layer 12. To compensate for these different widths bi and ba, a transverse side of the plate 4, in this embodiment the second transverse side 8, runs partially at an angle in relation to the longitudinal sides 5 and 6. In the embodiment, a part of the region of the second transverse side 8 ar-
ranged in the thermal insulation layer 2 and the second longitudinal side 6 include an angle a that is less than 90°. The angle a is advantageously 20° to 80°, in par- ticular 30° to 70°. In the embodiment, the angle is approximately 60°.
In the embodiment according to Fig. 20, the second concrete layer 12 is compara- tively thin.
The second concrete layer 12 has a thickness n that is advantageously less than 5cm, in particular less than 4cm, preferably less than 3cm.
However, a second concrete layer 12 with a greater thickness n may also be advantageous.
In all the embodiments, the thickness n of the second concrete layer 12 may advanta-
geously be less than 5cm, in particular less than 4cm, preferably less than 3cm.
The second concrete layer 12 advantageously has textile reinforcement.
Textile rein- forcement is provided for concrete layers 11, 12 with a thickness n of less than 5cm in particular.
The embodiment according to Fig. 21 shows a concrete slab 1 with a configuration that corresponds substantially to that of the concrete slab 1 from Fig. 20. The con- crete slab 1 from Fig. 21 differs from the embodiment according to Fig. 20 in the configuration of the portion of the plate 4 arranged within the thermal insulation layer 2. In addition to the recesses 10 that separate the fingers 13 from one anoth-
er, the plate 4 according to Fig. 21 also has a further recess 40. This further recess 40 is arranged in the region of the plate 4 positioned within the thermal insulation layer 2. Due to this further recess 40, webs 42 are formed on either side of the fur- ther recess 40. This reduces the transfer of heat from the second end portion 20 to the first end portion 19.
In the embodiment according to Fig. 22, the end portions 19 and 20 are offset in relation to one another in the longitudinal direction of the plate 4. The portion of the plate 4 arranged in the thermal insulation layer 2 is shaped like a parallelogram.
In the embodiment, the end portions 19 and 20 have the same width b.
The trans-
verse sides 7 and 8 are inclined at an angle a of less than less than 90° in relation to the longitudinal sides 5 and 6. In the embodiment according to Fig. 22, the angle a is approximately 60°. The two longitudinal sides 7 and 8 are inclined in the same direction.
As a result, the length d of the plate 4 is greater than the width b of the end portions 19 and 20. It may also be advantageous for the end portions 19 and
20 to be of different widths b.
The embodiment according to Fig. 23 shows a concrete slab 1 that has a connecting anchor 3 with a plate 4. In the embodiment, the plate 4 has five fingers 13 on each longitudinal side 5, 6. The height h of the plate 4 is considerably smaller than its length d.
In the embodiment, the height h is less than half of the length d.
The thickness k of the thermal insulation layer 2 is comparatively small.
Recesses 10 opposite bases 30 are spaced a distance c apart.
Since the bases 30 of the recesses
10 on both longitudinal sides 5 and 6 project into the thermal insulation layer 2, in the embodiment according to Fig. 23 opposing bases are spaced only a small dis- tance c apart.
In this embodiment the length e of the fingers 13 is greater than the distance c.
Figs. 24 to 29 show different versions of plates 4 of connecting anchors 3 that differ in terms of height h and length d.
In each case, the number of fingers 13 is adapted to the length d in question.
The plates 4 shown in Figs. 23 to 29 have ten receivers 14 on each transverse side 7, 8, five receivers 14 being arranged on either side of the median plane 31. The receivers 14 are arranged mirror symmetrically in relation to the median plane 31, thereby obviating the need to consider the orientation of the plate 4 when producing a concrete slab 1.
The configuration of the receivers 14 is shown in detail in Fig. 24a.
As shown in Fig. 24a, a snap-in element 41 that reduces the entry opening into the receiver 14. Is arranged at each receiver 14. The remaining opening to the outside is preferably slightly smaller than the diameter of a limiting element 15 to be arranged in the receiver 14. As a result, the limiting element 14 snaps into the receiver 14 and is held securely in the receiver 14, particularly during the fitting of the connecting an- chor 3 on a thermal insulation layer 2. As shown in the drawings, in the embodi-
ment the snap-in element 21 is arranged on the site of a receiver 14 away from the median plane 31.
The plate 4 shown in Fig. 24 has two fingers 13 on each longitudinal side 5, 6. The height h is approximately 0.5 to 1.5 times the length d of the plate 4. In the embod-
iment shown in Fig. 25, three fingers are provided on each longitudinal side 5, 6. Accordingly, the length d of the plate 4 is increased in comparison to the height h.
In the embodiment according to Fig. 26, seven fingers 13 are provided on each lon- gitudinal side 5, 6. Here the length d is considerably greater than the height h.
Fig. 27 showsan embodiment with four fingers 13 on each longitudinal side 5, 6. In the embodiments shown in Figs. 23 to 27, the height h of the plate 4 is identical.
The variation in the length d modifies the forces that can be transmitted between the concrete layers 11 and 12 and so serves to adapt a connecting anchor 3 to the pre- vailing forces.
Figs. 28 and 29 show further embodiments of plates 4 of connecting anchors 3 that have a greater height h than the embodiments shown in Figs. 23 to 27. Accordingly, the distance c between the recesses 10 opposite the bases 30 is also increased.
The plates 4 in Figs. 28 and 29 each have two fingers 13 on each longitudinal side 5, 6.
Another number of fingers 13 on each longitudinal side 5, 6 may also be advanta- geous.
The greater height h allows the use of the plates 4 for thermal insulation layers 2 of greater thickness.
In the embodiment shown in Fig. 28, the height h is approximately 1 to 2 times the length d.
In the embodiment shown in Fig. 29, the height h is 5 to 10 times the length d.
In the embodiments according to Figs. 23 to
29, the dimensions of the fingers 13 and of the recesses 10 are identical.
Due to the resulting increase in the distance c in the embodiment according to Fig. 29, it is possible to arrange at least one base 30 of a recess 10 outside the thermal insula- tion layer 2.
The embodiments shown in Figs. 23 to 29 also have bent portions 21 to 24 in their end portions 19 and 20. Further advantageous embodiments result from any combination of the features of the embodiments described above.