US20090235601A1

US20090235601A1 - Wall unit

Info

Publication number: US20090235601A1
Application number: US12/407,288
Authority: US
Inventors: Eoghan MELLETT
Original assignee: Off Site Construction R&D Ltd
Current assignee: Off Site Construction R&D Ltd
Priority date: 2008-03-19
Filing date: 2009-03-19
Publication date: 2009-09-24

Abstract

A method of manufacturing a wall unit comprises assembling a set of substantially parallel vertical elongated wall ties having opposite edges which are substantially coplanar on each side of the set. Each wall tie has a plurality of triangular openings distributed along its length with the openings of adjacent wall ties substantially aligned in a horizontal direction. A plurality of reinforcing rods are inserted horizontally through respective sets of aligned openings. Due to the triangular configuration of the openings each rod is deflected under gravity towards, and comes to rest adjacent, an edge of the wall tie. One or more formwork panels are secured to the substantially coplanar edges on each side of the wall ties.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application related to and claims priority to Irish Patent Application Serial Number S2008/0203, filed Mar. 19, 2008, Irish Patent Application Serial Number S2008/0204, filed Mar. 19, 2008, Irish Patent Application Serial Number S2008/0205, filed Mar. 19, 2008, and Irish Patent Application Serial Number S2008/716, filed Sep. 3, 2008, the entirety of all which are incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

n/a

FIELD OF INVENTION

The present invention relates to wall units such as, but not limited to prefabricated wall units.

BACKGROUND OF THE INVENTION

A type of wall construction is known in which formwork panels are mounted vertically upright and parallel to one another on a solid concrete floor, and the gap between the two filled with concrete. When the concrete is set the formwork panels may be removed, or left in place to form an integral part of the wall. In the later case they are known as permanent formwork panels and are typically made of cement—see, for example, WO 2004/091903.
It is therefore desirable to provide an improved wall unit for use in this type of construction, as well as a method of manufacturing such a wall unit and a wall tie for use in the construction of such a unit.

SUMMARY OF THE INVENTION

According to the present invention there is provided a wall unit comprising a set of substantially parallel elongated wall ties having opposite edges which are substantially coplanar on each side of the set so as to lie in two substantially parallel planes containing said edges, at least one reinforcing mesh recessed into the wall ties on at least one side of the set by being received in slots in the wall tie edges on that side of the set, and at least one formwork panel secured to the substantially coplanar edges on each side of the set of wall ties.
The invention further provides a method of manufacturing a wall unit comprising assembling a set of substantially parallel elongated wall ties having opposite edges which are substantially coplanar on each side of the set so as to lie in two substantially parallel planes containing said edges, recessing at least one reinforcing mesh into the wall ties on at least one side of the set by inserting the mesh in slots in the wall tie edges on that side of the set, and securing at least one formwork panel to the substantially coplanar edges on each side of the set of wall ties.
The invention further provides a wall tie for spacing opposite substantially parallel formwork panels in a wall unit, the wall tie comprising an elongated member with substantially parallel opposite flat longitudinal edges for retaining a formwork panel, each edge having a plurality of slots which intermittently interrupt the edge to allow a reinforcing mesh to be recessed into the wall tie clear of the edge.
The invention also provides a wall unit made by the above method. According to a further aspect of the present invention there is provided a method of manufacturing a wall unit comprising assembling a set of substantially parallel vertical elongated wall ties having opposite edges which are substantially coplanar on each side of the set, each wall tie having a plurality of openings distributed along its length between its opposite edges with the openings of adjacent wall ties substantially aligned in a horizontal direction, inserting a plurality of reinforcing rods horizontally through respective sets of aligned openings, the openings being configured such that under gravity each rod is deflected towards, and comes to rest adjacent, an edge of the wall tie, and securing at least one formwork panel to the substantially coplanar edges on each side of the set of wall ties.
The invention also provides a wall unit made by the above method.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

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

FIG. 1 shows on the left hand side, a side view and on the right hand side a perspective view of a wall tie used in the construction of a wall unit (FIG. 8) according to a first embodiment of the invention.

FIG. 1 a is a horizontal cross-section through the set of vertical wall ties shown in FIG. 2 which is used as the starting point in the manufacture of the wall unit of FIG. 8.

FIGS. 2 to 7 are perspective views of the wall unit of FIG. 8 in successive stages of manufacture.

FIG. 2 a is a cross-section of the apparatus of FIG. 1 prior to the engagement of the support rails with the spacer.

FIG. 8 shows the resulting wall unit according to the first embodiment of the invention.

FIG. 9 is a schematic plan view illustrating a T-shaped join between wall units

FIG. 10 is a perspective view of a wall tie used in a second embodiment of the invention.

FIGS. 11( a) to 11(d) are vertical cross-sections through the wall unit according to the second embodiment of the invention at various stages of its construction.

DETAILED DESCRIPTION OF THE INVENTION

In the drawings the same reference numerals have been used for the same or equivalent components in the various embodiments.
Referring to FIG. 1, a wall tie 10 used in the construction of the wall unit of FIG. 8 comprises an elongated member 12 having a generally I-shaped cross-section with substantially parallel opposite flat longitudinal edges 14. The member can be formed from metal including steel or aluminum or from a polymer, for example, PVC or composite material according to the engineering requirements for the wall unit. Each edge 14 has a plurality of slots 16 which intermittently interrupt the edge at regular intervals to allow a reinforcing mesh to be recessed into the wall tie clear of the edge 14, as will be described. The wall tie 10 also has a plurality of openings 18 distributed along its length between the opposite edges 14, and a short tab 20 at each end allows the lower end of the wall tie, when assembled into a wall unit with like ties as will be described, to locate between a pair of parallel floor-mounted support rails of the kind described in U.S. application Ser. No. 12/366,157, the disclosure of which is herein incorporated by reference.
Referring now to FIGS. 1 a and 2, the first stage in manufacturing the wall unit is to assemble a set of substantially vertical wall ties 10 side-by-side and substantially parallel to one another. Preferably, the ties are loaded into a floor mounted magazine and thereafter held in place in the temporary state by a jig (not shown) from which they depend in spaced apart relationship. The wall ties 10 have their opposite edges 14 substantially coplanar on each side of the set of wall ties so that all the edges 14 on one side of the set lie substantially in a first plane P1 (FIG. 1 a) and all the edges 14 on the other side of the set lie substantially in a second plane P2, the planes P1, P2 being substantially parallel to one another. Also, the openings 18 in adjacent wall ties are horizontally aligned.
Next, FIG. 3, vertical steel reinforcing rods 22 are inserted between adjacent wall ties 10 so as to extend substantially parallel to the wall ties along the opposite vertical edges of a rectangular window opening 24 (FIG. 8) subsequently formed in the set of wall ties. The rods 22 are secured to the wall ties 10 by twisted wire.
Then, FIGS. 3 and 4, a respective rectangular steel mesh 26 having a vertical pitch the same as the spacing of the slots 16 and a horizontal pitch the same as the spacing of the wall ties 10, is set into the slots 16 on each side of the set of wall ties (only one mesh is shown in FIG. 3). In particular, each horizontal rod 28 of the mesh 26 enters a respective set of horizontally aligned slots 16, while each vertical rod 30 enters the gap between a pair of adjacent wall ties 10. Thus each mesh is recessed into the wall ties 10 behind, i.e. clear of, the opposite flat edges 14.
Next, FIG. 4, horizontal steel reinforcing rods 32 are inserted through the aligned openings 18 so as to extend along opposite horizontal edges of the rectangular window opening 24 (FIG. 8) subsequently to be formed. The rods 32 are secured to the wall ties 10 and/or to the mesh 26 by twisted wire. At his point the vertical steel reinforcing rods 22 can also be secured to the mesh.
Now, FIG. 5, each side of the wall tie assembly is covered with edge-to-edge abutting cement formwork panels 34 which are adhesively and/or mechanically secured to the substantially coplanar wall tie edges 14 on each side of the set of wall ties. Preferably, a polyurethane based adhesive may be used, although any suitable fixing mechanism can be employed including screws. In the case where a rectangular opening is to be formed in the finished wall unit, the panels 34 are pre-cut to define the periphery of the opening, as indicated at 36. Next, pull-out bars 38 are slid into each end of the assembly. Each bar 38 has a pair of legs 40 which are slidably inserted into horizontally aligned slots 18 alongside respective horizontal mesh rods 28. The bars 38 may be pulled out to any desired extend from the end of the wall tie assembly, for a purpose to be explained.
Now the rectangular section 42 of wall ties 10 and mesh 26 revealed in the panel opening 36 is cut out, FIG. 6, to form the window opening 24. A reveal 44 is now inserted into the opening 24 to close off the gap between the cut edges of the panels 34, FIGS. 7 and 8.
At this point the wall unit is complete except for its concrete filling, and is preferably pre-fabricated off-site and transported as a self-supporting unit to the construction site.
At the construction site the unit is located on a pair of parallel floor-mounted support rails of the kind described in the above U.S. patent application Ser. No. 12/366,157, the short tabs 20 at the bottom edge of the unit locating between the rails. When the unit is in its final position, a concrete filling is poured into the gap between the formwork panels 34 and allowed to set. To avoid the concrete escaping, the vertical gap between the panels 34 at the ends of the unit are closed off either by the unit abutting edge-to-edge against another such unit, with the gap between the two being permanently bridged by further cement board permanent formwork, or by the unit joining another wall at a T shaped junction, for example as shown in FIG. 9.
In FIG. 9 three wall units 50 a, 50 b and 50 c are shown meeting at a T-junction, prior to pouring the concrete filling. The units 50 a and 50 c are in-line and the vertical gap between their panels 34 are closed on one side by a permanent formwork panel 52, and on the other side by the unit 50 b. The three units are coupled by their pull-out bars 38 which are wired together and become embedded in the concrete to reinforce the T-join.
Barcodes (or other machine-readable identifiers) are applied to the pre-fabricated wall units as they are produced and the units are shipped with their associated support rails and formwork panels 52 which are also bar-coded.
When a rail is scanned on site with a handheld scanner attached to a PDA on which a model of the building is either stored or accessible across a network, the PDA can display where the rail is to be fixed on the ground. Similarly, before being placed in position, the wall unit and formwork panels 52 can be scanned to ensure they are properly located and also to update the progress of the construction through the PDA.
The number of parallel side-by-side wall ties 10 in a particular wall unit, as well as their length and the distance between their opposite edges, may be varied according to the required dimensions of the wall unit.
A second embodiment of the invention will now be described with reference to FIGS. 10 and 11 (FIG. 11 d is an enlarged view of part of the final structure shown in FIG. 11 c).
Referring to FIG. 10, a wall tie 100 used in the second embodiment comprises an elongated member 112 having a generally I-shaped cross-section with substantially parallel opposite flat longitudinal edges 114. The member can be formed from metal including steel or aluminum or from a polymer, for example, PVC or composite material according to the engineering requirements for the wall unit. Struts 116 extending between the opposite edges 114 define a plurality of triangular openings 118 distributed along the length of the wall tie between the opposite edges 114. A short tab (not shown) at each end allows the lower end of the wall tie, when assembled into a wall unit with like ties as will be described, to locate between a pair of parallel floor-mounted support rails of the kind described in U.S. patent application Ser. No. 12/366,157, which is incorporated herein by reference.
The first stage in manufacturing the wall unit is to assemble a set of substantially vertical wall ties 110 side-by-side and substantially parallel to one another, in the manner shown in FIG. 2 for the prior assembly. Preferably, the ties are loaded into a floor mounted magazine and thereafter held in place in the temporary state by a jig (not shown) from which they depend in spaced apart relationship. The wall ties 110 have their opposite edges 14 substantially coplanar on each side of the set of wall ties so that all the edges 14 on one side of the set lie substantially in a first plane P1 (FIG. 11 a) and all the edges 14 on the other side of the set lie substantially in a second plane P2, the planes P1, P2 being substantially parallel to one another. Also, the triangular openings 118 in adjacent wall ties are horizontally aligned.
Next, FIG. 11 b, steel reinforcing rods 132 are inserted horizontally through respective sets of aligned triangular openings 118—in particular, the rods are inserted through sets whose triangular openings, such as those indicated at 118 a, have a downwardly pointing lowermost angle adjacent an edge 114 of the wall tie. Therefore, when released, each rod 132 is deflected under gravity towards, and comes to rest adjacent to, an edge 114. As shown, vertically consecutive rods 132 come to rest adjacent alternate edges of the wall ties. The rods 132 are secured to the wall ties 110 by twisted wire
Next, vertical steel reinforcing rods (not shown) are inserted between adjacent wall ties 110 so as to extend substantially parallel to the wall ties, and are secured by twisted wire.
Now, FIGS. 11 c and 11 d, each side of the wall tie assembly is covered with edge-to-edge abutting cement formwork panels 134 which are adhesively and/or mechanically secured to the substantially coplanar wall tie edges 114 on each side of the set of wall ties. Preferably, a polyurethane based adhesive may be used, although any suitable fixing mechanism can be employed including screws. In the case where a rectangular door or window opening is to be formed in the finished wall unit, the panels 134 are pre-cut to define the periphery of the opening in the manner previously described, and the horizontal and vertical reinforcing rods are positioned to avoid the location of the opening. As before, a reveal (not shown) is inserted into the opening to close off the gap between the cut edges of the panels 134. Pull-out bars (not shown) but similar to the bars 38 may be fitted.
At this point the wall unit is complete except for its concrete filling, and is preferably pre-fabricated off-site and transported as a self-supporting unit to the construction site.
At the construction site the unit is located on a pair of parallel floor-mounted support rails of the kind described in the above U.S. patent application Ser. No. 12/366,157, the short tabs at the bottom edge of the unit locating between the rails. When the unit is in its final position, a concrete filling is poured into the gap between the formwork panels 134 and allowed to set. To avoid the concrete escaping, the vertical gap between the panels 134 at the ends of the unit are closed off either by the unit abutting edge-to-edge against another such unit, with the gap between the two being permanently bridged by further cement board permanent formwork, or by the unit joining another wall at a T shaped junction.
Barcodes (or other machine-readable identifiers) are applied to the pre-fabricated wall units as they are produced and the units are shipped with their associated support rails and bridging formwork panels which are also bar-coded.
When a rail is scanned on site with a handheld scanner attached to a PDA on which a model of the building is either stored or accessible across a network, the PDA can display where the rail is to be fixed on the ground. Similarly before being placed in position, the wall unit and bridging formwork panels can be scanned to ensure they are properly located and also to update the progress of the construction through the PDA.
The number of parallel side-by-side wall ties 110 in a particular wall unit, as well as their length and the distance between their opposite edges, may be varied according to the required dimensions of the wall unit.
The invention is not limited to the embodiments described herein which may be modified or varied without departing from the scope of the invention.

Claims

1. A wall unit comprising:

a set of substantially parallel elongated wall ties having opposite edges which are substantially coplanar on each side of the set so as to lie in two substantially parallel planes containing said edges,

at least one reinforcing mesh recessed into the wall ties on at least one side of the set by being received in slots in the wall tie edges on that side of the set, and

at least one formwork panel secured to the substantially coplanar edges on each side of the set of wall ties.

2. The wall unit as claimed in claim 1, further including apertures in the wall ties which are aligned in a direction substantially normal to the longitudinal direction of the wall ties, and at least one reinforcing rod extending through the apertures along an edge of a rectangular opening in the set of wall ties.

3. The wall unit as claimed in claim 1, further including at least one reinforcing rod extending substantially parallel to and between adjacent wall ties along an edge of a rectangular opening in the set of wall ties

4. The wall unit as claimed in claim 1, wherein each wall tie has a generally I-shaped cross-section.

5. The wall unit as claimed in claim 1, having a concrete filling in the gap between the formwork panels.

6. A wall tie for spacing opposite substantially parallel formwork panels in a wall unit, the wall tie comprising:

an elongated member with substantially parallel opposite flat longitudinal edges for retaining a formwork panel, each edge having a plurality of slots which intermittently interrupt the edge to allow a reinforcing mesh to be recessed into the wall tie clear of the edge.

7. The wall tie as claimed in claim 6, wherein the wall tie has a plurality of apertures distributed along its length between the opposite edges.

8. The wall tie as claimed in claim 6, having a generally I-shaped cross-section.

9. The wall tie as claimed in claim 6 formed from one of a metal, polymer or composite material.

10. The wall tie as claimed in claim 6 wherein said flat longitudinal edges are arranged to adhesively and/or mechanically retain a formwork panel.

11. A method of manufacturing a wall unit comprising:

assembling a set of substantially parallel elongated wall ties having opposite edges which are substantially coplanar on each side of the set so as to lie in two substantially parallel planes containing said edges,

recessing at least one reinforcing mesh into the wall ties on at least one side of the set by inserting the mesh in slots in the wall tie edges on that side of the set, and

securing at least one formwork panel to the substantially coplanar edges on each side of the set of wall ties.

12. The method as claimed in claim 11, wherein the wall ties include apertures which are aligned in a direction substantially normal to the longitudinal direction of the wall ties, the method further includes inserting at least one reinforcing rod through the apertures to lie along an edge of a rectangular opening in the set of wall ties.

13. The method as claimed in claim 11, further including inserting at least one reinforcing rod substantially parallel to and between adjacent wall ties to lie along an edge of a rectangular opening in the set of wall ties.

14. The method as claimed in claim 11, wherein each wall tie has a generally I-shaped cross-section.

15. The method as claimed in claim 11, further including filling the gap between the formwork panels with concrete.

16. A method of manufacturing a wall unit comprising:

assembling a set of substantially parallel vertical elongated wall ties having opposite edges which are substantially coplanar on each side of the set, each wall tie having a plurality of openings distributed along its length between its opposite edges with the openings of adjacent wall ties substantially aligned in a horizontal direction,

inserting a plurality of reinforcing rods horizontally through respective sets of aligned openings, the openings being configured such that under gravity each rod is deflected towards, and comes to rest adjacent, an edge of the wall tie, and

17. The method claimed in claim 16, wherein the openings are triangular and each rod comes to rest at the lowermost angles of the respective set of aligned triangular openings.

18. The method claimed in claim 16, wherein vertically consecutive rods come to rest adjacent alternate edges of the wall ties.

19. The method claimed in claim 16, further including filling the gap between the formwork panels with concrete.

20. A wall unit made by the method of claim 16.