GB2460662A

GB2460662A - A collapsible support mechanism for the use in the formation of a concrete slab, raft or beam.

Info

Publication number: GB2460662A
Application number: GB0810160A
Authority: GB
Inventors: Kelly Louise Ross
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-06-04
Filing date: 2008-06-04
Publication date: 2009-12-09
Also published as: GB0810160D0

Abstract

A support mechanism comprises collapsible support structures (1) each of which is extended and locked in position by a tapered wedge (10), allowing the construction of formwork (5) over the supports (1) for forming form a concrete slab, raft or beam. When the concrete has cured, the support structures (1) are collapsed by removing the tapered wedges (10), allowing the support mechanism (11) to be removed from the void between the underside of the formwork (5) and the ground. A wedge can be removed by pulling on a wire 13 or bar with a hook engaging in a hole (12).

Description

Page 1 Support mechanism for forming a foundation raft, stab or beam.

This invention relates to a support mechanism for the use in the formation of a concrete slab, raft or beam.

When building on ground, which is liable to subsidence or heave, it is well known to erect the building or other superstructure on a raft, slab or beam, itself supported by piles, with the underside of the raft, slab or beam spaced above the ground by a void or compressible material. The void or compressible material, which prevents any heave from being significantly transmitted to the underside of the raft, slab or beam, has, previously, taken a variety of forms.

Typically a collapsible or crushable spacer, made for example of hardboard, cardboard, and/or polystyrene has been used. However, these techniques are generally expensive.

Furthermore, collapsible spaces can collapse prematurely, typically in wet weather, and crushable spacers require additional space to avoid the transmission of the heave to the raft, slab or beam, through the crushed material.

This invention aims to provide a support mechanism which overcomes the above problems, is easy to use, cheap to manufacture, simple in operation and potentially reduces the carbon footprint by recycling the support mechanism.

This invention, by means of a simple support mechanism, a rigid structure is provided on which to construct the necessary raft, slab or beam. The ability to collapse the support mechanism, when appropriate, ensures that it can be removed and reused.

It is envisaged that the method of forming a concrete raft, slab or beam for a building or other superstructure would comprise of the following steps:-erect formwork, which is spaced above the ground by means of the support mechanism; pouring concrete in the formwork to form the concrete raft, slab or beam; and when the concrete is set, releasing the support mechanism to provide a void between the underside of the raft, slab or beam and the ground.

This invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of this invention in its fully extended position Figure 2 is a schematic end on view of this invention in its fully extended position Figure 3 is a schematic side view of this invention in its collapsed position Figure 4 is a schematic end on view of this invention in its collapsed position.

As can be seen in Figures 1 and 2, a support structure (1) is shown in its fully extended position. Within the support mechanism (11) there are three support structures (1), as shown in Figure 1. The support structures (1) rest on top of a suitable base layer (2), which is placed over the surface of the ground (3). The three support structures (1) are connected together by a metal C' section top tray (4), on to which sits the permanent formwork (5), which is used to construct the raft, slab or beam.

Page 2 It can be seen in Figure 2, that the support structure (1) has a top plate (6), on to which the top tray (4) sits. The support structure (1) has a square base plate (7) which sits on the base layer (2). To the base plate (7) a lower vertical section (8) is fixed. To the top plate (6) an upper vertical section (9) is also fixed, such that the upper vertical section (9) fits over the lower vertical section (8). Both the upper vertical section (9) and the lower vertical section (8) are held in place by a removable tapered wedge (10). The tapered wedge (10) ensures that the upper vertical section (9) and the lower vertical section (8) are kept at a set distance apart.

As can be seen in Figures 3 and 4, a support structure (1) is shown in its collapsed position.

The support structure is only collapsed once the concrete raft, slab or beam has been poured and set. The support structure is collapsed by the removal of the tapered wedge (10), which is facilitated by tying a steel wire (13) through a hole (12) in the tapered wedge (10). This allows the upper vertical section (9) to side downwards within the lower vertical section (8).

An alternative method of removing the tapered wedge (10), maybe by the use of a steel hook' bar, which can be threaded through the hole (12) in order to pull on the tapered wedge (10). Once the support mechanism (11) has been collapsed, it can be easily removed from below the raft, slab or beam, for reuse. Page3

Claims

Claims 1. A support mechanism for use in the formation of a concrete foundation raft, slab or beam for a building or other superstructure, the support mechanism comprising: a base member for engagement, in use, with the ground; a top member for engagement, in use, with the raft, slab or beam; connecting means for connecting the base member and the top member such that they are relatively moveable between a close configuration and an open configuration; a support structure provided between the base member and the top member for, in use, retaining the base member and the top member in the open configuration; a removable wedge allowing the collapse of the support structure.
2. A support mechanism according to claim 1, wherein the collapsible mechanism comprises of a support structure connected to a tapered wedge connecting vertical sections which interconnect with each other.
3. A support mechanism according to claim 1, which comprises of a support structure with a base member, which when in use, connects with the surface ground.
4. A support mechanism according to claim 1, which ftLrther comprises of a series of support structures which are interconnected to each other by a top tray.
5. A support mechanism according to claims 1 and 2 wherein the tapered wedge, when inserted in the vertical sections enables the support structure to remain in its extended position.
6. A support mechanism according to claims 1 and 2 wherein the tapered wedge, when removed from the vertical sections, allows the collapse of the support structure.
7. A support mechanism substantially as herein described with reference to, and as illustrated by the accompanying drawings.
8. A method of forming a concrete foundation raft, slab or beam for a building or other superstructure, the method comprising the steps of:-constructing formwork, which is spaced above the ground by means of the support mechanism according to any one of the proceeding claims, pouring concrete in the formwork to form the raft, slab or beam, when the concrete has cured, collapsing the support mechanism to provide a void between the underside of the formwork and the ground, when collapsed, the removal of the support mechanism from the void, to allow for reuse.