AU2009222558A1

AU2009222558A1 - Expansion joints and formwork for concrete

Info

Publication number: AU2009222558A1
Application number: AU2009222558A
Authority: AU
Inventors: Mark Anthony Connolly; Paul Francis Connolly; David Boyd Taylor
Original assignee: Connolly Key Joint Pty Ltd
Current assignee: Leviat Pty Ltd
Priority date: 2003-03-25
Filing date: 2009-10-01
Publication date: 2009-10-22
Anticipated expiration: 2024-03-03
Also published as: AU2008207677A1; AU2009101012B4; AU2008207677B2; AU2009101012A4; AU2004200839A1; AU2009222558B2

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "EXPANSION JOINTS AND FORMWORK FOR CONCRETE" The following statement is a full description of this invention, including the best method of performing it known to us: 1 TITLE: EXPANSION JOINTS AND FORMWORK FOR CONCRETE THIS INVENTION relates to expansion joints and formwork for concrete. Expansion joints are provided between adjacent concrete slabs 5 to accommodate the thermal contraction and expansion of the slabs as the ambient temperature varies. In extreme conditions, eg., in full sunlight, the temperature variation over a day may be 30-40 0 C. If insufficient capacity for expansion is provided, there is a tendency for one slab to be vertically displaced relative to an adjacent slab as the first slab attempts to move up 10 and over the other slab. There have been many types of expansion joints used in the past, but these usually have limitations, including cost of manufacture, ease of installation and/or expansion capacity, and inability to be used in continuous concrete pours. 15 SUMMARY OF THE INVENTION It is an object of the present invention to provide an expansion joint member designed to avoid, or at least ameliorate the deficiencies of the known joints. It is a preferred object of the present invention to provide such 20 an expansion joint member which can be used for both sealed and unsealed joints between slabs. It is a further preferred object of the present invention to provide an expansion joint member which can be used, or modified, to act as formwork, for the perimeter of concrete slabs as a substitute for conventional 25 timber, steel or plastic formwork. Other preferred objects of the present invention shall become apparent from the following description. Throughout the specification, the terms "substantially vertical" and "substantially horizontal" shall be used to describe the common 2 orientation of a component when in use. In one aspect, the present invention resides in an expansion joint member, including: a substantially vertical, planar body; 5 at least two, vertically spaced, substantially horizontal, flanges extending from one side face of the body; and a plurality of sets of aligned holes in the flanges operable to receive supporting stakes or pins; the body, or a first portion of the body spaced from the one side 10 face, being compressible to accommodate thermal expansion of concrete slabs when separated by the body wherein: the body, or the first portion of the body spaced from the one side face, is formed of resiliently compressible material integral with, or attached to, a second portion of the body incorporating the one side face. 15 In one preferred embodiment, the second portion and the flanges are formed from sheet metal (eg., steel or aluminium) which is optionally roll-formed to shape. Preferably, the first portion of the body is formed by an elongate strip of resiliently compressible material, eg., an elastomeric material, such as rubber or foam-rubber, which may have a tear 20 off top portion or cover strip. A suitable material is sold under the trade mark "ABELFLEX". In a second embodiment, the body is formed of a relatively low density (or aerated) plastic (eg., expanded polystyrene); or the second portion of the body is formed of a relatively rigid, non-compressible plastic 25 (eg., PVC) and the first portion is formed of the low-density (or aerated) plastic, eg., as a co-extrusion, or is adhered to the second portion, eg., by a suitable adhesive or thermal welding. In a third embodiment, the body may be formed of a hollow extrusion where internal ribs are compressible to allow the "partial collapse" 3 of the body to accommodate thermal expansion of the adjacent concrete slabs. The "partial collapse" is preferably a controlled, resilient "collapse" of the body. Preferably, releasable locking means are provided between the 5 body and/or the flanges, and the stakes or pins, to enable the vertical position of the expansion joint member, relative to an adjacent slab to be poured, to be vertically adjusted. Preferably, spaced holes are provided in the body, or in the second portion of the body, of the expansion joint member, to allow steel 10 reinforcing rods and/or dowel members (used to keep slabs in vertical alignment) to extend through the expansion joint member. BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying 15 drawings, in which: FIG. 1 is a sectional end view of a first embodiment of the expansion joint member; FIG. 2 is a similar view of a second embodiment; FIG. 3 is a similar view of a third embodiment; 20 FIGS. 4 and 5 are perspective views of the first embodiment in use; and FIGS. 6 and 7 are respective section end views of joints formed, corresponding to FIG. 5 and 4, respectively DETAILED DESCRIPTION OF THE 25 PREFERRED EMBODIMENTS Referring to FIGS. 1 and 4 to 7, the expansion joint member 10 has substantially vertical body 11 where the body has a second body portion 12 and a pair of vertically spaced, substantially horizontal flanges 13, 14 roll formed from a single piece of galvanised sheet steel. Spaced pairs of holes 4 15, 16 in the flanges 13, 14 are adapted to receive stakes 17 which are releasably locked relative to the expansion joint member 10 by, eg., wedges 18 to allow the vertical height of the expansion member to be selectively adjusted. (In an alternative embodiment, not shown, the holes 15, 16 may 5 be non-circular, and are releasably engaged by flanges or other releasable locking formations on the stakes 17.) The first portion 20 of the body 11 may be formed by an elongate strip of "ABELFLEX" (Registered Trade Mark) resiliently compressible material (or other resiliently compressible elastomeric material) 1o which is fixed to the second portion 12, eg., by contact (or other suitable) adhesive (or double-sided tape) (not shown)). The first body portion 20 has a removable top strip 21, as illustrated in more detail in FIG. 5. In the embodiment shown in FIG. 5, the top strip 21 may be removed to leave a recess or groove 19 which may be filled with a sealant (not shown) to seal 15 the expansion joint between the slabs CS. It will be noted that the first portion 20 is of greater height (eg., by 10mm) than the second portion 12 of the body 11. For the sealed type joints shown in FIGS. 5 and 6, the expansion joint member 10 will be installed in the configuration shown in FIGS. 5 and 6 where the top edge 22 20 of the first portion 20 provides a screeding surface for the concrete. (FIG. 6 shows the joint, after the concrete slabs have been poured, but before the top strip 21 has been removed and the sealant applied to the groove 19.) For a non-sealed type joint of FIGS. 4 and 7, the expansion plate member 10 will be used in an inverted configuration, where the adjacent top edges of the 25 first and second portions 20, 12, will provide the screeding surface. The flanges 13, 14 are offset by 10mm, relative to the centre line of the first body portion 20 and equally spaced about the centre line of the second body portion 12. The holes 23 are offset relative to the centre line of the second body portion 12, but are equally spaced about the centre 5 line of the final expansion joint. A plurality of holes 23 are provided in the second body portion 12 (and may also be provided through the first body portion 20) to allow reinforcing steel rods and/or dowels 30, to extend through the body 11. The 5 dowels 30 may be of any suitable cross-section (eg., circular, square, rectangular, thin planar). It will be readily apparent to the skilled addressee that the resiliently compressible material of the first body portion 20 will accommodate up to, eg., 10-15mm of thermal expansion/contraction 10 between adjacent concrete slabs CS. Referring to the embodiment of FIG. 2, the expansion joint member 110 has a substantially vertical body 111 with substantially horizontal flanges 113, 114, each having holes 115, 116 therethrough. The body 111 is formed integrally with the flanges 113, 114 by 15 an extrusion process, the body 111 being hollow, and divided into "zones" by resiliently compressible ribs 124. Spaced holes 123 through the body 111 allow the passage of steel reinforcing rods and/or dowels as hereinbefore described. In the third embodiment of FIG. 3, the expansion joint member 20 210 again has a body 211 and flanges 213, 214 (with holes 215, 216) integrally formed by an extrusion method. The body 211 is formed of plastics material with a high percentage of void spaces (or aeration) to allow resilient compression of the body in the horizontal direction by the adjacent concrete slabs CS. 25 In an alternative embodiment, not shown, the body 211 may be formed by a co-extrusion, where the second body portion and flanges are integrally formed of a readily non-compressible, rigid material, eg, PVC, and the first body portion (spaced from the flanges 213, 214) are formed, by co extrusion, of the compressible (ie., aerated) material.

6 As shown in FIGS. 1, 2, 3 and 6, a strip of tear-off tape 21A, 121A, 221A may be provided to provide a clear joint line. In addition, as shown in FIGS. 2 and 3, a tear-off moulding strip 121, 221 may be provided on the body 112, 212, to enable the expansion 5 joint members 110, 210 to be used in the preparation of sealed joints. The specific profiles illustrated are by way of illustrative examples only and their specific shapes are not essential to putting the invention into effect. In addition, the profiles may be formed, eg., by folding or other io suitable metal-working techniques, in addition to roll-forming. The present invention provides expansion joint members, for concrete slabs, which are relatively inexpensive to manufacture, easy to install, and readily adaptable to a wide range of intended applications. Various changes and modifications may be made to the 15 embodiments described and illustrated without departing from the present invention.

Claims

1. An expansion joint member, including: a substantially vertical, planar body; at least two, vertically spaced, substantially horizontal, flanges 5 extending from one side face of the body; and a plurality of sets of aligned holes in the flanges operable to receive supporting stakes or pins; the body, or a first portion of the body spaced from the one side face, being compressible to accommodate thermal expansion of concrete 10 slabs when separated by the body, wherein: the body, or the first portion of the body spaced from the one side face, is formed of resiliently compressible material integral with, or attached to, a second portion of the body incorporating the one side face.

2. A joint member as claimed in Claim 1 wherein: 15 the second portion and the flanges are formed from sheet metal optionally roll-formed to shape; and the first portion of the body is formed by an elongate strip of resiliently compressible material such as an elastomeric material, with an optional tear-off top portion or cover strip. 20

3. A joint member as claimed in Claim 1 wherein: the body is formed of a relatively low-density or aerated plastic; or the second portion of the body is formed of a relatively rigid, non compressible plastic and the first portion is formed of a low-density or aerated plastic, as a co-extrusion with the second portion, or is adhered to 25 the second portion by a suitable adhesive or thermal welding.

4. A joint member as claimed in Claim 1 wherein: the body is formed of a hollow extrusion where internal ribs are compressible to allow the "partial collapse" of the body to accommodate thermal expansion of adjacent concrete slabs in use. 8

5. A joint member as claimed in any one of Claims 1 to 4 wherein: releasable locking means are provided between the body and/or the flanges, and the stakes or pins, to enable a vertical position of the joint member, relative to an adjacent slab to be poured, to be vertically 5 adjusted.

6. A joint member as claimed in any Claim 1 or Claim 2 wherein: the first portion is of greater vertical height than the second portion; and the flanges are vertically offset relative to the centre line of the first portion, being equally spaced about the centre line of the second portion.

7. A joint member as claimed in Claim 6 wherein: a plurality of holes are provided through the first and second portions, to allow reinforcing rods and/or dowels to extend therethrough, the holes being vertically aligned with the centre line of the first portion. is

8. A joint member as claimed in Claim 3 or Claim 4 wherein: a moulding strip is detachably mounted on one end of the body and is removable, after the adjacent concrete slabs have been poured, to form a channel for a sealed joint.

9. A joint member as claimed in Claim 8 wherein: 20 the flanges are equally spaced about the centre line of the body; and a plurality of holes are provided through the body, to allow reinforcing rods and/or dowels to extend therethrough, the holes being aligned with the centre line of the combined body and moulding strip. 25

10. A joint member as claimed in any one of Claims 1 to 9 wherein: a strip of tear-off tape is provided at one end of the body, or of the first portion of the body , to be removed after adjacent concrete slabs are poured to provide a clear joint line.

11. A formwork for concrete slabs employing the expansion joint 9 member as claimed in any one of Claims 1 to 10.

12. A formwork as claimed in Claim 11 wherein: spaced holes or knock-outs are provided in the body of the expansion joint member, to allow steel reinforcing rods and/or dowel 5 members, used to keep slabs in vertical alignment, to extend through the body.

13. An expansion joint member substantially as hereinbefore described with reference to FIG. 1; or FIG. 2; or FIG. 3; or FIGS. 1, 4 an 7; or FIGS. 1, 5 and 6; of the accompanying drawings.