ES2761578T3 - Joint forming apparatus - Google Patents

Abstract

An apparatus (1) for forming a joint between concrete floor slab panels, the apparatus comprising: a dividing plate (2) for boundary with one side of a concrete floor slab panel; and first and second upper strips (3,4), the first upper strip (3) being able to connect with the dividing plate (2), and the second upper strip (4) being frangibly connected with the dividing plate and / or the first strip higher; wherein each of the first and second upper strips (3,4) comprises: an elongated concrete engagement member (9), wherein the longitudinal axis of the elongated concrete engagement member (9) is, in use , located parallel to the longitudinal axis of the dividing plate (2); and an upper section (11) comprising an elongated upper face (12) having an elongated edge (13) that can be configured to lie flush with the upper surface of a concrete floor slab panel; and an elongated concrete abutment face (14) extending from the elongated edge (13) of the upper face (12), abutment face (14) which is a continuous face adapted to pour concrete against it and which extends along length of the length of the corresponding upper strip (3,4); in which: the arrangement of the first and second upper strips (3,4) is such that, in use, after the concrete has been poured, the elongated concrete stop face (14) extends down the elongated edge (13) of the upper face (12) at an angle such that the angle between the abutment face (14) and the upper surface abutting the concrete floor slab panel is 65 ° to 135 °; and characterized in that each of the first and second upper strips (3,4) is unitary, so that the corresponding elongated concrete engagement member and the corresponding upper section are integrated into a single component.

Description

DESCRIPTION

Joint forming apparatus

Field of the Invention

The present invention relates to an apparatus for forming a joint between concrete floor slab panels, a concrete floor slab panel comprising the apparatus, a concrete floor comprising the apparatus, and a method of manufacturing a panel of concrete floor slab.

Background of the Invention

Generally, concrete floor slabs are poured as adjoining slab panels, and each slab panel is poured into a formwork; This formwork defines a space in which the concrete can be poured. The formwork can be constructed of wood, steel, aluminum, plastic, or the like. The formwork can be removed, which means it is removed once the concrete has cured. Alternatively, it can be a permanent formwork, which is part of the resulting concrete structure, for example by providing at least part of an edge of a panel of the resulting concrete slab. The formwork generally comprises one or more vertical elongated partition plates against which the concrete is poured. The partition plates ensure that the concrete is contained within the desired space. When a series of floor slab panels are poured side by side to form a concrete floor or slab, generally, the partition plates settle between adjacent slab panels and dowels or dowel plates are used, attached to the dividing plates, to connect the slab panels to transfer loads through the joint.

During the pouring of a concrete floor slab panel comprising permanent formwork, the formwork must be placed in such a way that the top edges of the formwork coincide with the finished floor level (FFL), i.e. the level of the top surface of the finished concrete floor slab.

The slab and the formwork rest on a sub-base. If the subbase level (SBL) varies, the formwork will rest on the highest point of the subbase. For this reason, generally, in practice to empty a concrete floor, a distance of around 15-25 mm is left. The thicknesses of concrete slabs are generally in the range of 150 to 200 mm. The formwork can be manufactured to the desired thickness specifications, which is usually done in 5mm increments. If you want to pour a concrete slab with a thickness of 180mm, for example, normally, a formwork with a depth of 155 - 165 mm is used. To achieve the desired finished floor level (FFL), a partition plate can be suspended at the desired FFL using suspension means. Such suspension means may consist for example of a jack, or pins may be placed on either side of the partition plate and bolts, which are commonly present in an apparatus to form the edge of a concrete slab, may be welded, thus suspending the dividing plate in the desired FFL. Furthermore, shims, adjustable feet, and the like can be used to position the formwork against the sub-base as desired and to hold it in place while the concrete is being poured.

After casting, the concrete slabs exhibit a normal drying shrinkage. This shrinkage can be exacerbated when the temperature of the concrete is reduced, for example in the case of concrete floor slabs for cold rooms. Shrinking concrete floor slabs is a slow process - it may take up to two years for a concrete slab to stop shrinking. Contraction of the concrete slab panels generally results in the opening of the joints between the slab panels, as each concrete slab panel contracts from the joint in a direction generally perpendicular to the longitudinal axis of the meeting. The type of joint that is adapted to accommodate such shrinkage or shrinkage of the concrete slab panel on one or each side of the joint is known as a "shrink joint." It is the opposite of an "expansion joint," which is adapted to accommodate the expansion of a concrete slab panel on one or each side of the joint when the slab panels are emptied with a preset gap between them, to allow thermal expansion of the slab panel, after contraction of the slab panel as a result of curing.

EP 1389648 A1 describes an apparatus for forming the edge of a concrete floor slab panel, the apparatus comprising a partition plate with a plurality of openings, dowels for engaging through the openings and sleeves for applying to the dowels, wherein the partition plate is provided with means to adjust its height above the sub-base. The apparatus may also comprise rails that can be supported by the partition plate.

Known appliances for forming a joint between concrete floor slab panels can use dowels to anchor to the concrete, i.e. connect the appliance to the concrete on each side, as shown in EP 1389648 A1. Such dowels are commonly spaced at regular intervals (approximately every 25 cm) along the length of the apparatus. However, there is no anchoring of the apparatus to the concrete between the plugs. Therefore if, for example, the apparatus is cut to a particular length and the final section is cut just before the plug, there could be almost 25 cm of free apparatus left without anchoring to the concrete.

There are some known systems that address the issue of intermittent latching by providing a device in which the dividing plate is "wrapped" in the upper part, with the result of a longitudinal flat surface, flush with the upper part of the slab panel; and a descending longitudinal concrete hitch, forming an angle said decline with respect to the horizontal and having regular cuts. Said partition plate may be combined back to back with another identical partition plate or with a shorter plate member having a similar "wrap-around" section at the top. These types of apparatus are shown for example in WO 2005/103412 A1 and WO 2010/094910 A1.

These systems provide a continuous engagement of the concrete along the length of the fixture through the descent, but at the level of the top surface of the concrete slab panel these fixtures do not contain a continuous face for the concrete to abut. As is known in the art, concrete is strong in compression, but weak in tension. This means that it is very difficult to get the concrete to “thin” over a radius, since thin sections of the concrete, such as fine edges, are very prone to cracking and cracking. Therefore, if a descent has a radius of curvature or a significant angle at which the top surface of a concrete slab panel is spliced, the area where the concrete abuts the curve will be a possible crack site. . WO00 / 23653 discloses a system in which a profile of metal sheet with reinforcement on its upper surface is provided. The reinforcement is anchored to the concrete slabs with fixing lugs

WO2005 / 111307 discloses a joint for concrete surfaces comprising male and female parts, both of which are made of sheet metal folded on themselves on the top surface. The height of the female part is limited compared to the male part. Both the male and female parts are provided with pins to anchor the corresponding parts in the concrete.

WO2010 / 008309 discloses a floor formwork system having calibrated steel bars that are welded with zigzag rails on a frame.

The object of the present invention is to provide an apparatus for forming a joint between concrete floor slab panels, the embodiments of which can improve the performance characteristics of the resulting concrete slab panels.

Declaration of the invention

In accordance with a first aspect of the present invention, there is provided an apparatus for forming a joint between concrete floor slab panels according to claim 1.

The term "elongated", as used in the context of the concrete hook member, the top face, the edge of the top face and / or the face of the concrete stop, means that the corresponding element has an elongated shape. Conveniently, the longitudinal axis of the elongated element, in use, is located parallel to the longitudinal axis of the dividing plate and, therefore, of the apparatus.

The elongated concrete hitch member extends into a region where, in use, the concrete would be cast, the arrangement being such that the strips can be secured to the adjacent concrete floor slab panels by means of their corresponding members concrete hitch. The purpose of the elongated concrete hitch member ”is to engage with the concrete on each side of the appliance. Once the concrete has been poured, the elongated concrete hitch members on each side of the top strips will be embedded in the concrete of concrete slab panels on each side of the appliance.

The elongated concrete stop face is a continuous face adapted to empty the concrete against which the length of the corresponding top strip extends. In use, the concrete can therefore abruptly elongate the abutment face, ie, there are no protrusions from the abutment face extending into the region where the concrete is poured. Conveniently, the face of the continuous concrete stop does not contain any openings. The concrete can abut the elongated abutment face along the length of the corresponding top strip.

The invention provides an apparatus that enables continuous engagement with adjacent concrete floor slab panels on either side of the joint, while providing a continuous face for the concrete to abut each side of the joint, which It can limit the risk of cracks. Therefore, the apparatus can significantly improve the performance characteristics of the resulting concrete floor slabs. Once emptied, the concrete slab panels tend to shrink during curing, causing the edges of the slab panels to separate. This exposes the top edge, or edge, of each individual slab panel to damage from loads such as vehicles, including, for example, trucks or forklifts, that pass through the joint. The upper strips help protect each edge from these damages and improve the longevity of the slab in the joints.

Each top strip comprises a top section having an elongated top face. The top face is the face of the appliance that would still be visible from above after the concrete has been poured. In one embodiment, the The elongated upper face of the upper section of one or each of the upper strips is at least 2 mm wide, or at least 3 mm wide, or at least 6 mm wide, or at least 8 mm wide. This can result in a stronger upper section and can allow for more effective edge protection. In one embodiment, the elongated top face is 3mm to 20mm wide, or 3mm to 15mm wide, or 3mm to 12mm wide, or 3mm to 10mm wide, or 6mm to 20mm wide, or 6mm to 15mm wide, or 6mm to 12mm wide, or 6mm to 10mm wide, or 7mm to 20mm wide, or 7mm to 15mm wide, or 7mm to 12mm wide, or 7mm to 10mm wide, or 8mm to 20mm wide, or 8mm to 15mm wide, or 8mm to 12mm wide, or 8mm to 10mm wide. In one embodiment, the elongated top face is about 5mm wide or about 10mm wide or about 15mm wide.

The upper section of each of the upper strips also has an elongated concrete butt face. In one embodiment, the elongated concrete stop face of the top section of one or each of the top strips is at least 2mm deep or at least 3mm deep or at least 6mm deep or at least 8mm deep. depth. In one embodiment, the elongated concrete stop face is 3mm to 20mm deep or 3mm to 15mm deep or 3mm to 12mm deep or 3mm to 10mm deep or 6mm at 20mm depth, 6mm to 15mm depth or 6mm to 12mm depth or 6mm to 10mm depth or 7mm to 20mm depth, 7mm to 15mm depth or 7mm to 12mm deep or 7mm to 10mm deep or 8mm to 20mm deep, 8mm to 15mm deep or 8mm to 12mm deep or 8mm to 10 mm deep. In one embodiment, the elongated concrete stop face is approximately 5mm deep or approximately 10mm deep or approximately 15mm deep. For the avoidance of doubt, the distance indicated by “depth” means the distance of the elongated edge that can be configured to be at the level of the upper surface of a concrete floor slab panel with the lower elongated edge of the concrete butt face elongated.

The arrangement is such that in use after pouring the concrete, the elongated concrete stop face extends down from the elongated edge of the top face at an angle such that the angle between the stop face and the top surface of the slab panel of concrete floor that is capped is 65 ° to 135 °. That is, in use, the elongated concrete stop face extends down from the elongated edge of the top face at an angle of 25 ° from the true vertical in the direction in which the angle between the stop face and the top surface of a butt concrete floor slab panel would be at an acute angle (i.e. the angle between the butt face and the top surface of the butt concrete floor slab panel would be 65 °) at 45 ° from the true vertical in the direction in which the angle between the abutment face and the top surface of a abutting concrete floor slab panel would be at an obtuse angle (i.e., the angle between the abutment face and the top surface of the butting concrete floor slab would be 135 °).

In use, the angle between the abutment face and the abutment surface of the abutting concrete floor slab panel may therefore be a right angle, an acute angle, or an obtuse angle. In one embodiment, in use, after the concrete is poured, the elongated concrete stop face extends down from the elongated edge of the top face at an angle such that the angle between the stop face and the top surface of the slab panel butt concrete floor is 70 ° to 135 ° or 75 ° to 135 ° or 80 ° to 135 ° or 85 ° to 135 ° or 65 ° to 130 ° or 70 ° to 130 ° or 75 ° to 130 ° or 80 ° to 130 ° or 85 ° to 130 ° or 65 ° to 125 ° or 70 ° to 125 ° or 75 ° to 125 ° or 80 ° to 125 ° or 85 ° to 125 ° or 65 ° to 120 ° or 70 ° to 120 ° or 75 ° to 120 ° or 80 ° to 120 ° or 85 ° to 120 ° or 65 ° to 115 ° or 70 ° 115 ° or 75 ° to 115 ° or 80 ° to 115 ° or 85 ° to 115 ° or 65 ° to 110 ° or 70 ° to 110 ° or 75 ° to 110 ° or 80 ° to 110 ° or 85 ° to 110 ° or 65 ° to 105 ° or 70 ° to 105 ° or 75 ° to 105 ° or 80 ° to 105 ° or 85 ° to 105 ° or 65 ° to 100 ° or 70 ° to 100 ° or 75 ° to 100 ° or 80 ° to 100 ° or 85 ° to 100 ° or 65 ° to 95 ° or 70 ° to 95 ° or 75 ° to 95 ° or 80 ° to 95 ° or 85 ° to 95 °.

In one embodiment, in use, after the concrete is poured, the elongated concrete stop face extends down from the elongated edge of the top face at an angle such that the angle between the stop face and the top surface of a slab panel Butt concrete floor slab is 90 ° to 135 °, i.e. the angle between the butt face and the top surface of the butt concrete floor slab panel is a right angle or an obtuse angle. In one embodiment, the angle between the abutment face and the top surface of the abutting concrete floor slab panel is 90 ° to 130 ° or 90 ° to 125 ° or 90 ° to 120 ° or 90 ° 115 ° or 90 ° to 110 ° or 90 ° to 105 ° or 90 ° to 100 ° or 90 ° to 95 °.

In one embodiment, in use, after the concrete is poured, the elongated concrete stop face extends down from the elongated edge of the top face at an angle such that the angle between the stop face and the top surface of a slab panel Buttressing concrete floor slab is 65 ° to 90 °, that is, the angle between the butt face and the top surface of a butting concrete floor slab panel is a right angle or an acute angle.

In one embodiment, the angle between the abutment face and the top surface of a abutting concrete floor slab panel is 70 ° to 90 ° or 75 ° to 90 ° or 80 ° to 90 ° or 85 ° to 90 °.

In one embodiment, in use, after pouring concrete, the elongated stop face extends vertically down from the elongated edge of the top face. This means that the angle between the abutment face and the top surface of a abutting concrete floor slab panel is a right angle, i.e. approximately 90 °. In this embodiment, the elongated concrete stop face can therefore be located parallel to the partition plate. This provision it means that the concrete section abutting the abutment face can be at least the same thickness as the depth of the abutment face and, normally, there is no thinning along the abutment face, thus limiting the risk of cracking.

In one embodiment, the upper section of one or each of the upper strips comprises an elongated Dutch fold or folds. Such a fold can reinforce the upper section.

As mentioned, the concrete slab panels tend to contract during curing, which causes the adjacent slab panels to separate, leaving a gap between them. To ensure that the appliance remains connected to the concrete on each side of the gap, to be able to transfer loads through the joint and to be able to protect the edges of each slab panel, it is important to ensure that the appliance is firmly anchored to the concrete of each slab panel. This is accomplished by the elongated concrete hook member on either side of the top two strips.

In one embodiment, the elongated concrete hook member of one or each of the top strips contains a plurality of openings. Such openings allow the elongated concrete hook members to become more strongly embedded in the concrete during casting and curing, and thus helps to secure the upper strips, and thus the apparatus, in position relative to the the concrete.

As noted, each of the first and second top strips comprises an elongated concrete hook member and an upper section, upper section comprising an elongated upper face and an elongated concrete stop face.

In one embodiment, one or each of the top strips further comprises a connecting section between the top section and the concrete hook member. In one embodiment, the arrangement is such that in use after the concrete is poured, the connecting section is located parallel or substantially parallel to the partition plate.

Throughout this specification, unless expressly noted otherwise, the term "substantially parallel" is to be understood as being at an angle of less than 20 ° from true parallel. In one embodiment, this is less than 19 °, less than 18 °, less than 17 °, less than 16 °, less than 15 °, less than 14 °, less than 13 °, less than 12 °, less than 11 ° , less than 10 °, less than 9 °, less than 8 °, less than 7 °, less than 6 °, less than 5 °, less than 4 °, less than 3 °, less than 2 ° or less than 1 ° from the true parallel. Any angle from the true angle can be on either side of the true parallel.

In an alternate embodiment, the concrete hook member of one or each of the top strips extends from a lower elongated edge of the elongated concrete stop face.

The apparatus according to the first aspect of the invention comprises a dividing plate and a first and a second upper strip, the first upper strip being able to connect with the dividing plate and the second upper strip being able to connect frangibly with the dividing plate and / or or the first top strip. The dividing plate and the two strips are therefore three different components.

The first top strip can be connected to the partition plate. The components can be connected, for example, frangibly or permanently.

In one embodiment, the first top strip is connected to the partition plate. The components can be connected, for example, frangibly or permanently.

The second top strip can be frangibly connected to the partition plate and / or the first top strip. In one embodiment, the second top strip frangibly connects to the partition plate and / or the first top strip. In one embodiment, the second top strip can be frangibly connected to the partition plate. In one embodiment, the second upper strip is frangibly connected to the partition plate.

In one embodiment, the second top strip can frangibly connect to the first top strip. In one embodiment, the second top strip is frangibly connected to the first top strip.

In one embodiment, the second top strip can frangibly connect to the partition plate and the first top strip. In one embodiment, the second top strip is frangibly connected to the partition plate and the first top strip.

In one embodiment, the first top strip is connected to the partition plate, and the second top strip is frangibly connected to the partition plate and / or the first top strip.

When the upper strips and the dividing plate are connected, the connection between the dividing plate and the first upper strip or between the dividing plate and the first and second upper strip is located in the region towards the top of the dividing plate; at least the bottom of the partition plate extends outside beyond the top strips. In use, after the concrete is poured, the upper strips will settle on the surface of the concrete floor, or close to it, providing a continuous face for the concrete to abut on each side of the joint and to ensure that the appliance remains firmly anchored in the concrete on both sides of the joint, while extending the partition plate further down towards the sub-base or even rests on the sub-base, allowing the partition plate to perform its usual function of helping to retain the concrete within the desired space.

In one embodiment, the top of the partition plate is located between the first and second top strips. In one embodiment, the partition plate and the first and second top strips are connected through cost-effective fasteners.

In one embodiment, the partition plate is adapted to support the first top strip. In one embodiment, the first and second top straps are connected through cost effective fasteners.

Cost effective fasteners fail under stress when shrinkage occurs during the curing process and the upper strips of adjacent slab panels separate. In one embodiment, the cost effective fasteners comprise low tensile strength bolts. Examples of such low tensile strength bolts include bolts formed of nylon, the threads of which will separate under contraction forces or whose stems fail under tension.

In one embodiment, one or each of the top strips is formed of an elongated flat section of material. In one embodiment, one or each of the top strips is formed of a metal, for example, steel.

According to the invention, each of the upper strips is unitary. This means that the elongated concrete coupling member and the upper section (comprising the elongated upper face and the elongated concrete stop face) are integrated in a single component.

In one embodiment, one or each of the top strips is formed of a single sheet of metal by rolling and / or folding.

The upper strips can be arranged to mate with each other along the linear or non-linear edges. In one embodiment, the top strips are arranged to mate with each other along linear edges. In one embodiment, the top strips are arranged to mate with one another along non-linear edges such as curved edges.

The partition plate may have a conventional construction, for example, such as that of EP 1389648 or the like.

In one embodiment, the partition plate is an elongated flat section of material.

In one embodiment, the partition plate is non-deformable. This means that the material of which the partition plate is made is not compressible by the concrete once the concrete has been poured on one or both sides of the partition plate.

In one embodiment, the partition plate is formed of a metal, such as steel. This can result in a partition plate with high mechanical strength, capable of withstanding the forces acting on it during the casting of concrete.

In one embodiment, the partition plate comprises a longitudinal fold at the top edge and / or the bottom edge of the partition plate. Said fold may for example be a longitudinal L-fold, a longitudinal J-fold, a longitudinal V-fold or a Dutch fold (in which the dividing plate folds completely on itself). Such a fold can reinforce the dividing plate.

In one embodiment, the partition plate comprises one or more openings. In one embodiment, the apparatus further comprises one or more dowel or dowel plates to engage through the one or more openings. These act to connect the resulting concrete slab panels and provide a load transfer procedure between adjacent slab panels.

The apparatus according to the first aspect of the invention can be used to form eg precast four leg intersections, three leg "T" intersections, corner units and cargo area corners.

In accordance with a second aspect of the present invention, there is provided a concrete floor slab panel comprising the apparatus according to the first aspect of the invention.

In accordance with a third aspect of the invention, a concrete floor comprising the apparatus according to the first aspect of the invention or a slab panel according to the second aspect of the invention is provided.

In accordance with a fourth aspect of the present invention, there is provided a method of manufacturing a concrete floor slab panel comprising the steps of:

(i) installing the apparatus according to the first aspect of the invention to form at least part of an edge of a space for pouring concrete; and

(ii) pour concrete into the space.

According to one embodiment, a method of manufacturing a concrete floor is provided, in which steps (i) and (ii) are carried out more than once.

Throughout the description and claims of the present specification, the words "comprise" and "contains" and variations of these words, for example "comprising" and "containing" means "including but not limited to ”And does not exclude other fractions, additives, components, whole numbers, or stages. On the other hand, the singular encompasses the plural unless the context requires it; in particular, when the indefinite article is used, it is to be understood that the descriptive memory contemplates the plural in addition to the singular, unless the context requires otherwise.

The preferred features of one aspect of the invention can be described in connection with any of the other aspects. Other features of the invention will become apparent from the following examples. Generally speaking, the invention extends to any novel feature or combination of novel features of the features disclosed in this specification (including any accompanying claims or drawings). Therefore, the characteristics, integers, traits, compounds, chemical fractions, or groups that are described in conjunction with a particular aspect, embodiment, or example of the invention are to be understood as applicable to any other aspect, embodiment, or example described herein. document unless it is incompatible with them. On the other hand, unless otherwise noted, any feature disclosed herein may be replaced by an alternate feature serving the same or a similar purpose.

When quoting upper and lower limits for a property, then an interval of values defined by a combination of any of the limits with any of the lower limits can also be deduced.

Specific Description

Embodiments of the present invention will now be described with reference to the accompanying figures, in which:

Figure 1 presents a perspective view of a first embodiment of the apparatus of the invention.

Figure 2 presents a cross-sectional view of the embodiment of Figure 1, perpendicular to its length, after concrete has been poured on both sides of the apparatus, with the second upper strip abutting the partition plate.

Figure 3 presents a cross-sectional view of the embodiment of Figure 1 perpendicular to its length, after concrete has been poured on both sides of the apparatus, with the second upper strip separated from the partition plate and the first upper strip in the direction perpendicular to the longitudinal axis of the joint.

Figure 4 presents a perspective view of a second embodiment of the apparatus of the invention.

As shown in Figures 1 to 4, the apparatus 1 generally comprises a partition plate 2 , a first upper strip 3 and a second upper strip 4.

The partition plate 2 is an elongated flat section of steel with a longitudinal J-fold 5 at its bottom edge. The partition plate 2 comprises openings 6 along its length at regular intervals. The openings 6 are adapted to receive the dowel plates 7. On one side of the partition plate 2, the dowel plates 7 are lined with the dowel sleeves 8, which, in use, allow the movement of the concrete as it sets. and it contracts. The upper strips 3, 4 are elongated sections of steel. Each of the upper strips 3, 4 is unitary.

Each of the upper strips 3, 4 contains an elongated concrete hook member 9 extending into the region where, in use, the concrete could be poured. Each concrete hook member 9 contains a plurality of openings 10 .

Each of the upper strips 3, 4 further contains an upper section 11. The upper section 11 has an elongated upper face 12. The upper face 12 is the face of the apparatus that would be visible from above after the concrete has been poured. The upper face 12 has an elongated edge 13 that, in use, will be located at the level of the upper surface of the concrete floor slab panel. The upper section 11 also has an elongated concrete stop face 14 that extends vertically down from the elongated edge 13 of the upper face 12 . As can be seen in Figures 2 and 3, this means that, in use, after pouring concrete, the angle between the abutment face 14 and the top surface of the abutting concrete floor slab panel is approximately 90 °. The elongated concrete stop face 14 is located parallel to the partition plate 2. The concrete stop face 14 provides a continuous face for the concrete to abut; the concrete can abut the elongated abutment face 14 along the length of the corresponding top strip without interruption. The concrete stop face 14 does not contain any openings.

In the presented embodiments, each of the upper strips 3, 4 contains a connection section 15 which is located parallel to the partition plate 2. Holes 16 are present in the connection sections 15 in the upper strips 3, 4 and in the partition plate 2; the upper strips 3, 4 and the partition plate 2 can be connected by placing low tensile strength bolts 17 through these holes 16.

In the first embodiment, presented in Figures 1-3, the upper section 11 of each of the upper strips 3,4 is formed by a simple Dutch fold. In this arrangement, if the steel from which the top strips 3, 4 are formed is 3 mm thick, the result will be an elongated top face 12 that is approximately 6 mm wide. The elongated concrete stop face 14 may be of the desired depth, such as approximately 10mm depth.

In the second embodiment, presented in Figure 4, the upper section 11 of each of the strips 3, 4 is formed by a Dutch fold that has been deployed outside of the divider plate 2 , resulting in an approximately perpendicular Dutch fold in the connecting section 15 of each of the upper strips 3, 4. In this arrangement, if the steel from which the strips 3, 4 are formed is 3 mm thick, the result will be an elongated concrete butt face 14 which is approximately 6mm deep. The elongated top face 12 may be as desired, for example, a width of about 10 mm.

In use, the partition plate 2 and the top strips 3, 4 are suspended at the desired FFL using support means, which may include suspension means, such as a jack. The jack can be secured on the sub-base, for example, through a pin. Additional pins can also be placed on the ground next to the partition plate and wedges can be placed between these pins and the partition plate 2, to secure the appliance to the sub-base at the desired location and prevent movement caused by pushing the concrete.

At this stage, the apparatus will form at least part of an edge of a concrete pouring space. The entire edge can be formed with the apparatus and the rest of the edges can also be formed with other units of the apparatus. Once the space for pouring concrete with the edges has been defined, that is, the formwork has been established, the concrete is poured into the space. The concrete is first poured into the other space on the partition plate 2 from the jack. Once the concrete has sufficiently set, the jack, pins, and shims are removed. After the concrete has been poured on the remaining side of the appliance.

Once the concrete has been poured, the upper strips 3, 4 are firmly anchored to the concrete by means of their concrete hook members 9 which have been embedded in the concrete. In addition, the edges of each concrete slab panel are protected. The concrete abuts the elongated abutment face 14 along the entire length of each of the top strips.

The concrete slab panels will exhibit normal drying shrinkage. As the concrete shrinks on each side of the joint, the top strips 3, 4 separate as they are anchored to the concrete. During this process the dowel plates 7 will slide into the dowel sleeves 8 so that a gap is opened between the slab panels. The partition plate will remain on the side of the first top strip 3.

The apparatus of the invention can allow for continuous engagement with adjacent concrete floor slab panels on either side of a joint, while providing a continuous face for the concrete to abut each side of the joint, which limits the risk of fissures. Therefore, the apparatus can significantly improve the performance characteristics of the resulting concrete floor slabs. Furthermore, the invention can provide a relatively light apparatus that has the required rigidity, improving the ease of use and hence the ease of fabrication of concrete floors.

Claims (15)

An apparatus (1) for forming a joint between concrete floor slab panels, the apparatus comprising: a partition plate (2) for abutting one side of a concrete floor slab panel; and first and second upper strips (3,4), being able to connect the first upper strip (3) with the dividing plate (2), and being able to connect the second upper strip (4) frangibly with the dividing plate and / or the first upper strip ; wherein each of the first and second upper strips (3,4) comprises: an elongated concrete latch member (9), wherein the longitudinal axis of the elongated concrete latch member (9) is, in use, located parallel to the longitudinal axis of the partition plate (2); and an upper section (11) comprising an elongated top face (12) having an elongated edge (13) that can be configured to be level with the top surface of a concrete floor slab panel; and an elongated concrete stop face (14) extending from the elongated edge (13) of the upper face (12), stop face (14) which is a continuous face adapted to pour concrete against it and extending along of the length of the corresponding upper strip (3,4); in which: the arrangement of the first and second upper strips (3,4) is such that, in use, after pouring the concrete, the elongated concrete stop face (14) extends down from the elongated edge (13) of the upper face (12) at an angle such that the angle between the abutment face (14) and the top surface abutting the concrete floor slab panel is 65 ° to 135 °; and characterized in that each of the first and second upper strips (3,4) is unitary, so that the corresponding elongated concrete hook member and the corresponding upper section are integrated into a single component. 2. The apparatus of claim 1, wherein each of the first and second top strips (3,4) is formed of a single sheet of metal by rolling and / or folding. 3. The apparatus of claim 1, wherein the elongated upper face (12) of the upper section (11) of one or each of the upper strips (3,4) is at least 6 mm wide. The apparatus of any one of the preceding claims, wherein the elongated concrete stop face (14) of the upper section (11) of one or each of the upper strips (3,4) is at least 6 mm deep. The apparatus of any one of the preceding claims, wherein, in use, after pouring concrete, the elongated concrete stop face (14) extends downward from the elongated edge (13) of the top face in an angle such that the angle between the abutment face and the top surface of the abutting concrete floor slab panel is 80 ° to 135 °. The apparatus of claim 5, wherein the angle between the abutment face (14) and the top surface of the abutting concrete floor slab panel is 90 ° to 135 °. The apparatus of any one of the preceding claims, wherein the upper section (11) of one or each of the upper strips (3,4) comprises an elongated Dutch fold. The apparatus of any one of the preceding claims, wherein one or each of the top straps (3,4) further comprises a connecting section (15) between the top section and the concrete hook member. 9. The apparatus of claim 8, the arrangement being such that, in use, after pouring concrete, the connecting section (15) is located parallel or substantially parallel to the partition plate. The apparatus of any one of the preceding claims, wherein the upper part of the partition plate (2) is located between the first and second upper strips (3,4). The apparatus of any one of the preceding claims, wherein the partition plate (2) is adapted to support the first upper strip (3). 12. The apparatus of any one of the preceding claims, wherein the partition plate (2) is non-deformable. 13. A concrete floor slab panel comprising the apparatus according to any one of claims 1-12. 14. A concrete floor comprising the apparatus according to any one of claims 1-12 or the slab panel of claim 13. 15. A method of manufacturing a concrete floor slab panel comprising the steps of: (i) installing the apparatus (1) according to any one of claims 1-12 of forming at least part of an edge of a space to pour concrete; and (ii) pour concrete into the space.