WO2015121538A1

WO2015121538A1 - A prefabricated movement joint system for concrete floors

Info

Publication number: WO2015121538A1
Application number: PCT/FI2015/050088
Authority: WO
Inventors: Patrick EVE
Original assignee: Peikko Group Oy
Priority date: 2014-02-14
Filing date: 2015-02-13
Publication date: 2015-08-20

Abstract

The invention relates to a prefabricated movement joint system (2) with top edge rails (3a and 3b) providing protection for the concrete floor slab (1a and 1b) edges. The top edge rails (3a and 3b) may have a plurality of anchors (6a and 6b) to embed in the concrete and position the system, which are formed from the parent steel of the rail (3) and not for example welded on. When the top edge rails (3a and 3b) are joined back to back with the possible use of yieldable fixings (5) they clamp and hold in position possible a nylon or other plastic shaped extrusion (7) and the divider plate (4) thus comprising the whole of the assembled system.

Description

A PREFABRICATED MOVEMENT JOINT SYSTEM FOR CONCRETE FLOORS

Field of the invention

The invention relates to prefabricated movement joint system as defined in the preamble of independent claim 1.

This invention relates to the forming of concrete floor slabs, particularly to the forming of the edges of the slabs or arris's, also to providing protection of said edges, and improved means for load transfer between adjacent slabs.

It is well known that concrete floor slabs are cast inside a formwork, commonly constructed of either timber or steel. This formwork provides an edge and defines a space in which to cast the concrete, some types of formwork are removed once the concrete sets, and some are designed to remain in place for the life of the floor.

Once cast, concrete slabs are prone to shrinkage during curing which causes the edges of the slabs to separate, and expose the upper edge or arris of each individual slab to damage from loads, such as lorries or fork trucks passing across the joint.

Individual slabs often support heavy loads passing from one slab to another and therefore require a method of load transfer between adjacent slabs, in order to prevent breakdown of the joint between adjacent slabs, caused by stresses induced by such loads Typically round, square or plate dowels and sleeves are embedded in the concrete to extend at 90° across the formed joint, and connect the slabs together in order to facilitate the transfer of a load from one slab across the joint to another.

Most available prefabricated joints are anchored into the concrete slabs by a plurality of

Shear Studs which have been welded on either side of the top rails along their length, said welded studs present a potential consequential risk of failure at the weld, and can cause severe problems if they break off after the slab has been cast, making re-welding in situ extremely difficult.

Many existing prefabricated joint manufacturers also produce a dowel and sleeve of their own specific design, and often manufacture their joint to be able to accommodate only their style of dowel or similar, other standard dowels may not fit the aperture provided in the divider plate.

Object of the invention

It is therefore an object of this invention to provide an improved prefabricated joint system which provides maximum protection to the newly formed joint edge in two planes as opposed to just one.

Short description of the invention

The prefabricated movement joint system of the invention is characterized by the definitions of independent claim 1.

Preferred embodiments of the prefabricated movement joint system are defined in the dependent claims.

In an embodiment of the prefabricated movement joint system, height adjustment is achieved by a customized jack arrangement which affixes to the prefabricated joint system by means of a threaded spigot on the jack which passes through a pre-punched aperture in the edge rails and is secured there by means of a nut on the other side - said jack arrangement is the subject of a separate patent.

In one aspect, the invention provides a prefabricated movement joint system for forming the edge of the concrete slab, the system comprising a divider plate that may be reinforced by a plurality of embossed ridges, which may be of any shape or design to suit. Said divider plate may be formed with a plurality of apertures, which may be of any shape or design required to accept most known dowel types and sizes, thereby permitting the use of a wide range of load transfer mechanisms. The dowels and sleeves shown as may be used in this system are the subject of a separate patent.

The divider plate, because of its possible clamp fixing between the two top edge rails, can provide in use a degree of height adjustment to accommodate for different thickness slabs. Said divider plate will preferably be formed from metal sheet, but other materials may be used, and is intended to be left in place between concrete floor slabs cast on each side thereof.

The prefabricated joint system may further comprise top edge rails which are preferably supportable by the divider plate, to provide protection in two planes to the edge of the concrete floor cast slabs. The top edge rails may further comprise a plurality of integrated anchors, which are formed from the parent metal of the top edge rails, and which become embedded in the concrete during curing and which fix the top edge rails in position.

The top edge rails of adjoining concrete floor slabs are preferably attached together with yieldable fixings wherein, as shrinking occurs during the curing process and the top edge rails of adjacent slabs are drawn apart, the fixings yield to allow for the movement. The yieldable fixing may comprise low tensile bolts, studs or rivets, for example formed from nylon or similar plastics, which will shear or part under the shrinkage forces. The fixings for the top edge rails are preferably located in first apertures formed through the top edge rails and comprise a close tolerance fit to the fixing, in order to ensure that adjacent top edge rails are accurately placed in position.

When the top edge rails are fixed together back to back, because of a possible radii created by the forming of the angles, a curved depression is evident. Said depression may hold detritus and possibly cause hard wheeled traffic traversing the joint to jar or bump. This potential problem may be removed by the use of a formed nylon or similar plastic extrusion, shaped in cross section to exactly fit the curved depression, Said extrusion may also include a suitable lip or tag at the bottom of the section which can be captured and clamped in position by the top edge rails.

List of figures

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which

Figure 1 is a cross section of one embodiment of the prefabricated movement joint system according to the invention, forming a joint between a first concrete floor slab and a second concrete floor slab,

Figure 2 is the same cross section of the prefabricated movement joint system as shown in figure 1 but with the addition of a proprietary plate dowel and sleeve to provide a load transfer mechanism, said dowel and sleeve are the subject of a separate patent,

Figure 3 is a cross section of the prefabricated movement joint system as shown in Figure 2 once the slabs have cured, shrinkage has taken place and the joint opened, thereby shearing the yieldable fixings,

Figure 4 is a detailed perspective view of the first top edge rail showing the formed angle and the anchors which are formed from the parent metal of the rail. This view also shows the apertures for the yieldable fixings and the Height Adjustment Jack,

Figure 4 is a detailed perspective view of the second top edge rail showing the formed angle and the anchors which are formed from the parent metal of the rail. This view also shows the apertures for the yieldable fixings and the Height Adjustment Jack,

Figure 6 is a perspective view of the divider plate showing at the top edge slots for the fixings and height adjustment jack spigot, a plurality of apertures along the length to accommodate most proprietary dowel types and load transfer systems, and a plurality of the embossed or raised strengthening ridges, which in this embodiment take the shape of a cross, but may be of any shape or size,

Figure 7 shows a perspective view of the formed nylon or any similar plastic type material extrusion, which is located uppermost between the top edge rails and is secured in position by means of being clamped between the top edge rails,

Figure 8 shows a perspective view of a assembled prefabricated movement joint system including top edge rails with formed angles and anchors, extruded plastic top strip, divider plate and yieldable fixings,

Figure 9 shows an end sectional view of a prefabricated movement joint system including top edge rails with formed angles and anchors, extruded plastic top strip, divider plate and yieldable fixings, and

Figure 10 shows a general perspective view of an assembled prefabricated movement joint system according to the invention, ready for use, as in figure 8, but with the addition of Dowels and Sleeves, also included in this view is a Height Adjustment Jack. Detailed description of the invention

The invention relates to a prefabricated movement joint system 2 such as an expansion joint system and/or a contraction joint system for a concrete floor slab arrangement.

The prefabricated movement joint system is configured to be arranged in a joint (not marked with a reference numeral) to be formed between a first concrete floor slab la and a second concrete floor slab lb when forming the first concrete floor slab la and the second concrete floor slab lb by casting.

The prefabricated movement joint system 2 comprises a first top edge rail 3a of metal or other material for providing edge protection in two planes for a first upper edge 15a of the first concrete floor slab la in the joint to be formed between the first concrete floor slab la and the second concrete floor slab lb in the concrete floor slab arrangement.

The prefabricated movement joint system 2 comprises a second top edge rail 3b of metal or other material for providing edge protection in two planes for a second upper edge 15b of the second concrete floor slab lb in the joint to be formed between the first concrete floor slab la and the second concrete floor slab lb in the concrete floor slab arrangement.

The prefabricated movement joint system 2 comprises a divider plate 4 of metal or other material to be arranged in the joint to be formed at least partly between the first concrete floor slab la and the second concrete floor slab lb in the concrete floor slab arrangement and at least partly between the first two top edge rail 3a and the second top edge rail 3a.

The divider plate 4 of metal or other material may be formed with a plurality of first apertures 12 and second apertures 13 and embossed strengthening ridges 9.The divider plate 4 may be in the form of a height adjustable divider plate, which is lockable into several positions between the first top edge rail 3a and the second top edge rail 3b so as to adjust the height of the divider plate 4 for example in accordance with the thickness of the first concrete floor slab la and the second concrete floor slab lb.

According to the invention as previously described above and shown in figures 1 to 10, the prefabricated movement joint system 2 may be manufactured in discrete lengths to suit or as required, and by virtue of the overlap shown, a plurality of the joints may be connected together in order to form the total desired length of joint.

The drawings show a prefabricated movement joint system 2, suitable for use in forming concrete floor slabs la, lb as shown in figure 1. The prefabricated movement joint system 2 as shown in figure 8 comprises a first top edge rail 3a possible provided with formed first anchors 6a, a second top edge rail 3b possible provided with formed second anchors 6b, a divider plate 4 as shown in figure 8 possible provided with a plurality of yieldable fixings 5.

The first top edge rail 3a and the second top edge rail 3b are preferably, as shown in the figures, elongate and can be provided in lengths and joined together and cut as required, comprising possible of a formed unequal angle, with the narrow plane facing uppermost to the top, and the other to the vertical, this angle being designed to provide armored protection to the edge of the first concrete floor slab la, or correspondingly, to the second concrete floor slab lb.

In the prefabricated movement joint system 2 one of the first top edge rail 3a and the second top edge rail 3b of the prefabricated movement joint system 2 may be formed into an angle to provide edge protection to a part of the top face (not marked with a reference numeral) and to a part of the joint face (not marked with a reference numeral) of the first concrete floor slab la in the joint to be formed between a first concrete floor slab la and a second concrete floor slab lb.

In the prefabricated movement joint system 2 one of the first top edge rail 3a and the second top edge rail 3b of the prefabricated movement joint system 2 may be formed into an angle to provide edge protection to a part of the top face and to a part of the joint face of the second concrete floor slab in the joint to be formed between a first concrete floor slab la and a second concrete floor slab lb.

In an embodiment of the prefabricated movement joint system 2 the first top edge rail 3a of the movement joint system 2 may have has a plurality of first anchors 6a to embed and position the first top edge rail 3a in the first concrete floor slab la so that at by at least one first anchor 6a of said plurality of first anchors 6a has been formed from the parent metal of a vertical plane of the first top edge rail 3a, as opposed to being welded on or affixed by some other method.

In an embodiment of the prefabricated movement joint system 2 the second top edge rail 3b of the prefabricated movement joint system 2 may have has a plurality of second anchors 6b to embed and position the second top edge rail 3b in the second concrete floor slab la so that at by at least one second anchor 6b of said plurality of anchors 6 has been formed from the parent metal of a vertical plane of the second top edge rail 3b, as opposed to being welded on or affixed by some other method.

In an embodiment of the prefabricated movement joint system 2 the first top edge rail 3a of the prefabricated movement joint system 2 comprise a first rail portion 16a and a second rail portion 17a. The first rail portion 16a of the first top edge rail 3a is to be arranged essentially parallel with a top face of the first concrete floor slab la. The second rail portion 17a of the first top edge rail 3a is to be arranged essentially parallel with a joint face (not marked with a reference numeral) facing the joint to be formed between the first concrete floor slab la and the second concrete floor slab lb. In this embodiment of the prefabricated movement joint system 2 the first rail portion 16a is provided in an essentially right angle in relation to the second rail portion 17a so that the first top edge rail 3a has an essentially L-shaped cross section form. In this embodiment of the prefabricated movement joint system 2 the first top edge rail 3a may have a plurality of first anchors 6a to be cast into concrete of the first concrete floor slab la to anchor the first top edge rail 3a in the first concrete floor slab la so that at least one first anchor 6a of said plurality of first anchors 6a has been formed by cutting and plastically deforming the material forming the second rail portion 17a of the first top edge rail 3a so that said at least one first anchor 6a is an integral part of the second rail portion 17a of the first top edge rail 3a and consist of material that has been used forming the second rail portion 17a of the first top edge rail 3a.

In an embodiment of the prefabricated movement joint system 2 the second top edge rail 3b of the prefabricated movement joint system 2 comprise a first rail portion 16b and a second rail portion 17b. The first rail portion 16b of the second top edge rail 3b is to be arranged essentially parallel with a top face of the second concrete floor slab lb. The second rail portion 16b of the second top edge rail 3b is to be arranged essentially parallel with a joint face facing the joint to be formed between the first concrete floor slab la and the second concrete floor slab lb. The first rail portion 16b is provided in an essentially right angle in relation to the second rail portion 17b so that the second top edge rail 3b has an essentially L-shaped cross section form. In this embodiment of the prefabricated movement joint system 2 the second top edge rail 3b may have a plurality of second anchors 6b to be cast into concrete of the second concrete floor slab lb and to anchor the second top edge rail 3b in the second concrete floor slab lb, and at least one second anchor 6b of said plurality of second anchors 6b has been formed by cutting and plastically deforming the material forming the second rail portion 17b of the second top edge rail 3b so that said at least one second anchor 6b is an integral part of the second rail portion 17b of the second top edge rail 3b and consist of material that has been used forming the second rail portion 17b of the second top edge rail 3b. In an embodiment of the prefabricated movement joint system, the first rail portion 16a of the first top edge rail 3a is in the form of an elongated flat sheet member having uniform thickness and the second rail portion 17a of the first top edge rail 3a is in the form of an elongated flat sheet member having uniform thickness so that the thickness of the first rail portion 16a of the first top edge rail 3a corresponds to the thickness of the second rail portion 17a of the first top edge rail 3a. In this embodiment, the first top edge rail 3a have a plurality of first anchors 6a to be cast into concrete of the first concrete floor slab la to anchor the first top edge rail 3a in the first concrete floor slab la, so that by at least one first anchor 6a of said plurality of first anchors 6a has been formed by cutting and plastically deforming material forming the second rail portion 17a of the first top edge rail 3a so that said at least one first anchor 6a is an integral part of the second rail portion 17a of the first top edge rail 3a and consist of material that has been used forming the second rail portion 17a of the first top edge rail 3a, and so that the second rail portion 17a of the first top edge rail 3a has a first opening 18a through the second rail portion 17a of the first top edge rail 3a at the location said at least one first anchor 6a has been formed of material forming the second rail portion 17a of the first top edge rail 3a. The first opening 18a increases the strength of the connection between the first top edge rail 3a and the first concrete floor slab la and increases the sheer strength of the movement joint system. The dimensions and the shape of the first opening 18a the in second rail portion 17a of the first top edge rail 3a may correspond at least partly to the dimensions and the shape of said at least one first anchor 6a. Alternatively, the dimensions and the shape of the first opening 18a the in second rail portion 17a of the first top edge rail 3a may correspond essentially to the dimensions and the shape of said at least one first anchor 6a. In this embodiment, said at least one first anchor 6a may have an elongated form, and said at least one first anchor 6a may have a thickness corresponding to the thickness of the second rail portion 17a of the first top edge rail 3a. In this embodiment, said at least one first anchor 6a may have an at least partly teethed side edge such as an at least partly saw-toothed side edge. In this embodiment, the first rail portion 16a of the first top edge rail 3a may be connected with the second rail portion 17a of the first top edge rail 3a by means of a first curved portion 19a of the first top edge rail 3a, wherein the thickness of the first curved portion 19a of the first top edge rail 3a corresponds to the thickness of the first rail portion 16a of the first top edge rail 3a and to the thickness of the second rail portion 17a of the first top edge rail 3a. Provision of a first curved portion 19a between the first rail portion 16a of the first top edge rail 3a and the second rail portion 17a of the first top edge rail 3a reduces impact damage for example to small fork truck wheels as opposed to sharp formed edges.

In an embodiment of the prefabricated movement joint system, the first rail portion 16b of the second top edge rail 3b is in the form of an elongated flat sheet member having uniform thickness, and the second rail portion 17b of the second top edge rail 3b is in the form of an elongated flat sheet member having uniform thickness, so that the thickness of the first rail portion 16b of the second top edge rail 3b corresponding to the thickness of the second rail portion 17b of the second top edge rail 3b. In this embodiment the second top edge rail 3b have a plurality of second anchors 6b to be cast into concrete of the second concrete floor slab lb to anchor the second top edge rail 3b in the second concrete floor slab lb, so that at least one second anchor 6b of said plurality of second anchors 6b has been formed by cutting and plastically deforming material forming the second rail portion 17a of the second top edge rail 3b so that said at least one second anchor 6b is an integral part of the second rail portion 17b of the second top edge rail 3b and consist of material that has been used forming the second rail portion 17b of the second top edge rail 3b, and so that the second rail portion 17b of the second top edge rail 3b has a second opening 18b through the second rail portion 17b of the second top edge rail 3b at the location said at least one second anchor 6b has been formed of material forming the second rail portion 17a of the second top edge rail 3b. The second opening 18b increases the strength of the connection between the first top edge rail 3a and the first concrete floor slab la and increases the sheer strength of the movement joint system. The dimensions and the shape of the second opening 18b the in second rail portion 17a of the second top edge rail 3b may correspond at least partly to the dimensions and the shape of said at least one second anchor 6b. Alternatively the dimensions and the shape of the second opening 18b the in second rail portion 17b of the second top edge rail 3b may correspond essentially to the dimensions and the shape of said at least one second anchor 6b. In this embodiment, said at least one second anchor 6b may have an elongated form, and said at least one second anchor 6b may have a thickness corresponding to the thickness of the second rail portion 17b of the second top edge rail 3b. In this embodiment said at least one second anchor 6b may have an at least partly teethed side edge such as an at least partly saw-toothed side edge. In this embodiment the first rail portion 16b of the second top edge rail 3b may be connected with the second rail portion 17b of the second top edge rail 3b by means of a second curved portion 19b of the second top edge rail 3b, wherein the thickness of the second curved portion 19b of the second top edge rail 3b corresponds to the thickness of the first rail portion 16b of the second top edge rail 3b and to the thickness of the second rail portion 17b of the second top edge rail 3b. Provision of a second curved portion 19a between the first rail portion 16b of the second top edge rail 3b and the second rail portion 17b of the second top edge rail 3b reduces impact damage for example to small fork truck wheels as opposed to sharp formed edges.

At least one of the first top edge rail 3a and the second top edge rail 3b may be provided with a plurality of first apertures 12 for receiving the yieldable fixings 5 and/or with another plurality of second apertures 13 for receiving the height adjusting jack 11 as shown in figure 10.

The first top edge rail 3a and the second top edge rail 3b of the prefabricated movement joint system 2 may be fixable back to back with the yieldable fixings 5 thereby clamping into position the divider plate 4 and an optional extrusion 7 of plastic such as nylon or other material, as shown in figure 7. The extrusion 7 serves two functions, firstly to keep out detritus from the curved depression and secondly to assist in smooth wheeled transition of the prefabricated movement joint system 2 once in situ.

A plurality of shaped openings 8 may be provided along the length of the divider plate 4. The shaped openings 8 are of a generally squat and wide shape in order to permit dowels 14 such as circular, square, or plate dowels to extend there through, thereby permitting the use of a wide variety of dowels and load transfer mechanisms.

Another optional feature of the divider plate 4 is a plurality of slots 15 uppermost along the top edge, these slots are there to permit the passage of yieldable fixings 5 and height adjustment jacks 11 through the first top edge rail 3a and the second top edge rail 3b when the prefabricated movement joint system 2 is assembled for use.

In order to strengthen the divider plate 4 to resist the flow of concrete being poured against it a plurality of embossed straightening ridges 9 as shown in figure 6 are formed, said embossed straightening ridges 9 may be of any suitable shape or design as required.

A view of the complete prefabricated movement joint system 2 or assembly ready for use, including plate dowels and sleeves 10 also a height adjusting jack 11 can be viewed in figure 10. The aforementioned plate dowels and jack are the subject of separate patents and do not form a part of this application.

Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be understood that the applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A prefabricated movement joint system for a concrete floor slab arrangement, wherein the prefabricated movement joint system (2) is configured to be arranged in a joint to be formed between a first concrete floor slab (la) and a second concrete floor slab (lb) in the concrete floor slab arrangement, characterized by the prefabricated movement joint system (2) comprising a first top edge rail (3a) of metal or other material for providing edge protection in two planes for a first upper edge (15a) of the first concrete floor slab (la) in the joint to be formed between the first concrete floor slab (la) and the second concrete floor slab (lb) in the concrete floor slab arrangement

a second top edge rail (3b) of metal or other material for providing edge protection in two planes for a second upper edge (15b) of the second concrete floor slab (lb) in the joint to be formed between the first concrete floor slab (la) and the second concrete floor slab (lb) in the concrete floor slab arrangement, and

a divider plate (4) of metal or other material to be arranged in the joint to be formed at least partly between the first concrete floor slab (la) and the second concrete floor slab (lb) in the concrete floor slab arrangement and at least partly between the first two top edge rail (3a) and the second top edge rail (3a).

2. The prefabricated movement joint system according to claim 1, characterized

by the first top edge rail (3a) of the prefabricated movement joint system (2) comprise a first rail portion (16a) and a second rail portion (17a), wherein the first rail portion (16a) of the first top edge rail (3a) is to be arranged essentially parallel with a top face of the first concrete floor slab (la), and wherein the second rail portion (17a) of the first top edge rail (3a) is to be arranged essentially parallel with a joint face facing the joint to be formed between the first concrete floor slab (la) and the second concrete floor slab (lb), and

by the first rail portion (16a) is provided in an essentially right angle in relation to the second edge rail portion (17a) so that the first top edge rail (3a) has an essentially L-shaped cross section form.

3. The prefabricated movement joint system according to claim 2, characterized

by the first top edge rail (3a) have a plurality of first anchors (6a) to be cast into concrete of the first concrete floor slab (la) to anchor the first top edge rail (3a) in the first concrete floor slab (la), and

by at least one first anchor (6a) of said plurality of first anchors (6a) has been formed by cutting and plastically deforming the material forming the second rail portion (17a) of the first top edge rail (3a) so that said at least one first anchor (6a) is an integral part of the second rail portion (17a) of the first top edge rail (3a) and consist of material that has been used forming the second rail portion (17a) of the first top edge rail (3a).

4. The prefabricated movement joint system according to claim 2, characterized

by the first rail portion (15a) of the first top edge rail (3a) is in the form of an elongated flat sheet member having uniform thickness,

by the second rail portion (17a) of the first top edge rail (3a) is in the form of an elongated flat sheet member having uniform thickness,

by the thickness of the first rail portion (15a) of the first top edge rail (3a) corresponding to the thickness of the second rail portion (17a) of the first top edge rail (3a),

by at least one first anchor (6a) of said plurality of first anchors (6a) has been formed by cutting and plastically deforming material forming the second rail portion (17a) of the first top edge rail (3a) so that said at least one first anchor (6a) is an integral part of the second rail portion (17a) of the first top edge rail (3a) and consist of material that has been used forming the second rail portion (17a) of the first top edge rail (3a), and so that the second rail portion (17a) of the first top edge rail (3a) has a first opening (18a) through the second rail portion (17a) of the first top edge rail (3a) at the location said at least one first anchor (6a) has been formed of material forming the second rail portion (17a) of the first top edge rail (3a).

5. The prefabricated movement joint system according to claim 4, characterized

by the dimensions and the shape of the first opening (18a) the in second rail portion (17a) of the first top edge rail (3a) corresponds at least partly to the dimensions and the shape of said at least one first anchor (6a).

6. The prefabricated movement joint system according to claim 4, characterized

by the dimensions and the shape of the first opening (18a) the in second rail portion (17a) of the first top edge rail (3a) corresponds essentially to the dimensions and the shape of said at least one first anchor (6a).

7. The prefabricated movement joint system according to any of the claims 4 to 6, characterized

by said at least one first anchor (6a) having an elongated form, and

by said at least one first anchor (6a) having a thickness corresponding to the thickness of the second rail portion (17a) of the first top edge rail (3a).

8. The prefabricated movement joint system according to any of the claims 4 to 7, characterized by said at least one first anchor (6a) having an at least partly teethed side edge such as an at least partly saw-toothed side edge.

9. The prefabricated movement joint system according to any of the claims 4 to 8, characterized

by the first rail portion (15a) of the first top edge rail (3a) being connected with the second rail portion (17a) of the first top edge rail (3a) by means of a first curved portion (19a) of the first top edge rail (3a), and

by the thickness of the first curved portion (19a) of the first top edge rail (3a) corresponding to the thickness of the first rail portion (15a) of the first top edge rail (3a) and to the thickness of the second rail portion (17a) of the first top edge rail (3a).

10. The prefabricated movement joint system according to any of the claims 1 to 9, characterized

by the second top edge rail (3b) of the prefabricated movement joint system (2) comprise a first rail portion (16b) and a second rail portion (17b), wherein the first rail portion (16b) of the second top edge rail (3b) is to be arranged essentially parallel with a top face of the second concrete floor slab (lb), and wherein the second rail portion (16b) of the second top edge rail (3b) is to be arranged essentially parallel with a joint face facing the joint to be formed between the first concrete floor slab (la) and the second concrete floor slab (lb), and

by the first rail portion (16b) is provided in an essentially right angle in relation to the second rail portion (17b) so that the second top edge rail (3b) has an essentially L-shaped cross section form.

11. The prefabricated movement joint system according to claim 10, characterized

by the second top edge rail (3b) have a plurality of second anchors (6b) to be cast into concrete of the second concrete floor slab (lb) and to anchor the second top edge rail (3b) in the second concrete floor slab (lb), and

by at least one second anchor (6b) of said plurality of second anchors (6b) has been formed by cutting and plastically deforming the material forming the second rail portion (17b) of the second top edge rail (3b) so that said at least one second anchor (6b) is an integral part of the second rail portion (17b) of the second top edge rail (3b) and consist of material that has been used forming the second rail portion (17b) of the second top edge rail (3b).

12. The prefabricated movement joint system according to claim 11, characterized

by the first rail portion (15b) of the second top edge rail (3b) is in the form of an elongated flat sheet member having uniform thickness, by the second rail portion (17b) of the second top edge rail (3b) is in the form of an elongated flat sheet member having uniform thickness,

by the thickness of the first rail portion (15b) of the second top edge rail (3b) corresponding to the thickness of the second rail portion (17b) of the second top edge rail (3b),

by the second top edge rail (3b) have a plurality of second anchors (6b) to be cast into concrete of the second concrete floor slab (lb) to anchor the second top edge rail (3b) in the second concrete floor slab (lb), and

by at least one second anchor (6b) of said plurality of second anchors (6b) has been formed by cutting and plastically deforming material forming the second rail portion (17a) of the second top edge rail (3b) so that said at least one second anchor (6b) is an integral part of the second rail portion (17b) of the second top edge rail (3b) and consist of material that has been used forming the second rail portion (17b) of the second top edge rail (3b), and so that the second rail portion (17b) of the second top edge rail (3b) has a second opening (18b) through the second rail portion (17b) of the second top edge rail (3b) at the location said at least one second anchor (6b) has been formed of material forming the second rail portion (17a) of the second top edge rail (3b).

13. The prefabricated movement joint system according to claim 12, characterized

by the dimensions and the shape of the second opening (18b) the in second rail portion (17a) of the second top edge rail (3b) corresponds at least partly to the dimensions and the shape of said at least one second anchor (6b).

14. The prefabricated movement joint system according to claim 12, characterized

by the dimensions and the shape of the second opening (18b) the in second rail portion (17b) of the second top edge rail (3b) corresponds essentially to the dimensions and the shape of said at least one second anchor (6b).

15. The prefabricated movement joint system according to any of the claims 12 to 14, characterized

by said at least one second anchor (6b) having an elongated form, and

by said at least one second anchor (6b) having a thickness corresponding to the thickness of the second rail portion (17b) of the second top edge rail (3b).

16. The prefabricated movement joint system according to any of the claims 12 to 15, characterized by said at least one second anchor (6b) having an at least partly teethed side edge such as an at least partly saw-toothed side edge.

17. The prefabricated movement joint system according to any of the claims 12 to 16, characterized

by the first rail portion (15b) of the second top edge rail (3b) being connected with the second rail portion (17b) of the second top edge rail (3b) by means of a second curved portion (19b) of the second top edge rail (3b),

by the thickness of the second curved portion (19b) of the second top edge rail (3b) corresponding to the thickness of the first rail portion (15b) of the second top edge rail (3b) and to the thickness of the second rail portion (17b) of the second top edge rail (3b).

18. The prefabricated movement joint system according to any of the claims 1 to 17, characterized by at least one of the first top edge rail (3a) and the second top edge rail (3b) have a plurality of second apertures (13) to suit yieldable fixings and height adjustment jacks (11).

19. The prefabricated movement joint system according to any of the claims 1 to 18, characterized by comprising a plurality of first apertures (12) for receiving low tensile yieldable fixings (5) for holding the first top edge rail (3a) and the second top edge rail (3b) in position with respect to each other.

20. The prefabricated movement joint system according to claim 29, characterized by the yieldable fixings (5) being variable to suit the strength and design of the concrete floor slabs (1).

21. The prefabricated movement joint system according to any of the claim 1 to 20, characterized by comprising a divider plate (4) in the form of a height adjustable divider plate, which is lockable into position between the first top edge rail (3a) and the second top edge rail (3b).

22. The prefabricated movement joint system according to any of the claims 1 to 21, characterized by the divider plate (4) have a plurality of shaped apertures (8) to accommodate dowels (14) or corresponding load transfer systems arranged to transfer loads between the first concrete floor slab (la) and the second concrete floor slab (lb).

23. The prefabricated movement joint system according to any of the claims 1 to 22, characterized by the divider plate (4) having a plurality of embossed or raised ridges (9) for the purpose of strengthening the divider plate (4).

24. The prefabricated movement joint system according to any of the claims 1 to 23, characterized by comprising an extrusion (7) of a nylon or similar plastic type material, shaped to suit a curved depression between the first top edge rail (3a) and the second top edge rail (3b).

25. The prefabricated movement joint system according to claim 24, characterized by the extrusion (7) can be clamped into position between the first top edge rail (3a) and the second top edge rail (3b), thereby preventing detritus from filling the depression and assisting in the smooth transition of wheeled traffic across the joint.

26. The prefabricated movement joint system according to any of the claims 1 to 25, characterized by at least one of the first top edge rail (3a) and the second top edge rail (3b) comprises a plurality of second apertures (13) for receiving height adjustment jacks (11) or other similar accessories.

27. The prefabricated movement joint system according to any of the claims 1 to 26, characterized by can be manufactured in discrete lengths and coupled together to provide the total desired length of joint.

28. The prefabricated movement joint system according to any of the claims 1 to 27, characterized by can be supplied for use either fully assembled or in Kit Form, for assembly by others.