BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an expansion joint for use in building construction.

2. Description of the Prior Art

In the construction of large areas of concrete decking which can either be on-ground decking or suspended decking, the decking is cast in sections with expansion joints being incorporated between adjacent sections principally to absorb movement between the sections primarily arising from temperature variation within the overall structure and possibly seismic loading. For suspended sections in multi-storey construction, movement between the sections can also arise from high wind loading which causes the structure to sway. The movement between the sections of the deck structure can be a combination of horizontal, vertical, and sideways movement and the expansion joint which is designed to accommodate the anticipated range of movement is installed in a gap between two adjacent sections.

For some applications it is necessary that the expansion joint while permitting the anticipated movement between the concrete sections also provides a waterproof seal between the sections. An example of such a requirement is in multi-storey car parks in which individual storeys may be wholly or partially exposed to the prevailing weather conditions and in wet conditions will be exposed to water brought in on the tyres or bodies of vehicles using the car park. Existing expansion joints for car parks and the like are subject to extensive wear both from vehicular traffic and pedestrian traffic and may be subject to a failure whereby the expansion joint is no longer watertight allowing water to leak through the joint into whatever structure lies beneath and which, when the car park is part of a retail complex, could be part of a retail area leading to possible disruption to trading and perhaps generating safety issues. It is to be noted that even for an on-ground deck structure water penetration between adjacent concrete sections may need to be prevented to prevent damage to the underlying substructure. Significant ongoing repair and rectification work is required with some current expansion joint systems which cause that problem. SUMMARY OF THE INVENTION

According to the present invention there is provided an expansion joint for providing a substantially watertight seal between two concrete sections in building construction, the joint comprising an elongate seal of elastomeric material comprising a main sealing body for location under compression between opposing edges of the concrete section and integral lateral wings, one wing extending from each side of the main sealing body to overlie the surface of the adjacent concrete section or a rebate formed in the surface of the adjacent concrete section, and elongate locking plates for extending in the length direction of the seal, the locking plates being adapted to be anchored to the concrete sections with the plates overlying the lateral wings to thereby retain the wings to the concrete sections.

Advantageously each lateral wing has an upstanding lip extending longitudinally along its outer edge, and the underside of the associated locking plate is formed with a keyway for receiving the lip to provide a positive lock for the lip.

BRIEF DESCRIPTION OF THE DRAWINGS

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

Figure 1 is an end view of an elongate elastomeric seal within the expansion joint of the preferred embodiment;

Figure 2 is a perspective view corresponding to Figure 1 ;

Figure 3 is a schematic section showing the expansion joint installed between two concrete sections, with seal locking plates of the joint being surface-mounted;

Figure 4 is a schematic section similar to Figure 3 but showing the seal locking plates mounted within rebates in the surface of the concrete sections; and

Figure 5 is an end view of one of the seal locking plates, the particular plate shown being that used in the configuration of Figure 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The expansion joint of the preferred embodiment of the invention principally comprises an elongate seal 2 of an extruded elastomeric material comprising a main body 4 which lies between, and in contact with, the opposed edges of the concrete sections 5, and lateral wings 6 integrally formed with the main body 4 and overlying the surface of the adjacent concrete sections 5 (see Fig. 3) or the surface of a rebate formed in the concrete sections 5 (see Fig. 4). The seal is of elongate form typically of many metres in length, 25m in one practical example, and the main body 4 comprises a complex array of intersecting ribs extending in the length direction of the seal. The design of the main body provides for significant compressibility of the seal from side-to-side and also significant flexibility. The main body 4 is mounted between the opposed side edges of the concrete sections 5 under lateral compression which is the condition shown in Figures 3 and 4 and in that state the main body 4 can absorb further compressive loading consequent on the concrete sections moving closer together, or expansion while still remaining under compression, consequent on the concrete sections moving further apart. Accordingly throughout its range of use the seal acts as a compression seal between the two concrete sections. It is to be noted that the precise configuration of the main body of the seal and in particular that of its intersecting ribs can differ from that particularly shown. The upper surface 4a of the main body which is its wear surface contacted by vehicular and pedestrian traffic is of ribbed form in the embodiment shown.

Each of the lateral wings 6 is retained to the concrete section 5 by an elongate locking plate 10 which overlies the wing and which is firmly secured to the concrete section externally of the wing for example by expansion anchors 12 set into the concrete section whereby the wing is firmly clamped between the underside of the plate and the concrete section. The plate is preferably of metal, aluminium for example. In practice the plate will be supplied in lengths of several meters and a series of plates will be laid end to end to run for the length of the seal. It will be understood from Figs. 3 and 4 that the configuration of the plate 10 will vary depending on whether it is to be mounted in a rebate or surface-mounted. Advantageously the outer edge of each wing 6 includes an upstanding lip 13 received in a groove or keyway 14 which formed in the underside of the locking plate as clearly shown in Fig. 5.

Although Figure 5 just shows the locking plate shaped for use in the configuration of Fig. 3, that for use in the configuration of Figure 4 will be substantially similar.

To install the seal a watertight adhesive is applied between the underside of each wing 6 and the adjacent surface of the concrete and adhesive is also applied to the underside of the locking plate 10 to bond and seal the plate 10 to the wing 6 and to the concrete externally of the wing 6 and this bonding action in conjunction with the fixing provided by the anchors 12 between the locking plate 10 and concrete provides very reliable retention of the seal. The engagement of the upstanding lip 13 of each wing 6 within the longitudinal keyway 14 in the underside of the locking plate also provides a positive retention; accordingly this engagement mechanically locks the outer edge of the seal to the locking plate.

Advantageously the underside of the locking plate 10 in the area which lies externally of the wing 6 includes a keyway 16 of undercut shape (see Fig. 5), as shown dovetail shape by way of example, to assist in bedding the plate to the concrete.

As shown in Figures 3 and 4 the outer surface 4a of the main body 4 of the seal in its installed state is substantially flush with the upper surface of the two locking plates 10. The upper surface of each locking plate 10 is preferably provided with an anti-slip finish, such as a knurled finish.

It is particularly preferred that the material from which the seal is formed is heat weldable whereby two lengths of seal can be connected onsite by heat welding to provide a watertight joint between the adjacent lengths. A preferred material for the seal is a thermoplastic vulcanisate such as that sold under the trade mark "Santoprene" which is an elastomeric material which has properties comparable with that of vulcanised rubber while having processing characteristics of thermoplastic material.

The locking plates in conjunction with the upstanding lips on the wings of the seal provide reliable and positive retention of the seal even in conditions of heavy wear. The presence of the locking plates also prevent spalling of the edges of the concrete sections. The seal and its method of retention by the locking plates provides an effective watertight seal between the two concrete sections and it is anticipated that it will avoid the need for frequent maintenance necessary in some existing systems.