Foundation void former unit

Abstract

A void former unit ( 10 ) for use in a concrete foundation ( 25 ) includes a plurality of tyres ( 12 ) located side-by-side. The void former can have a retention element in the form of tyre tread or conveyor belt ( 16 ) located around the perimeter of the plurality of tyres. Typically, each tyre has an in-use upper side wall removed therefrom, thus enabling a fill material ( 36 ) to be located within each tyre, and between each tyre and the retention element, and in any voids between the tyres in the unit The improvement comprises arranging a capping element ( 80 ) on the unit and/or in-filling the unit with fill material ( 74,78 ) formed from tyre or conveyor belt material. The unit can be used in a concrete foundation by arranging one or more of the void former units on the ground and in-filling the units with the fill material and/or covering the units with the capping element prior to concrete pouring.

1 . A unit for use as a void former in a concrete foundation, the unit including a plurality of tyres located side-by-side, wherein a continuous capping element is located on top of the unit in use.  
   
   
       2 . A unit as claimed in  claim 1  wherein the capping element is fastened to the unit in use.  
   
   
       3 . A unit as claimed in  claim 1  or  2  wherein the capping element defines a platform on the void former which in use can support a human user, reinforcing mesh, or utilities pipework and/or ducting.  
   
   
       4 . A unit as claimed in any one of the preceding claims wherein the capping element is a roll-formed sheet material.  
   
   
       5 . A unit as claimed in  claim 4  wherein the roll-formed sheet material is roll-formed steel which is optionally galvanised or coated.  
   
   
       6 . A unit as claimed in  claim 4  or  5  wherein the roll-formed sheet is corrugated.  
   
   
       7 . A unit for use as a void former in a concrete foundation, the unit including a plurality of tyres located side-by-side, wherein a fill material formed from tyre or conveyor belt material is located within and/or between each tyre in use.  
   
   
       8 . A unit as claimed in  claim 7  wherein the tyre or conveyor belt material is located in voids within and between each tyre.  
   
   
       9 . A unit as claimed in  claim 7  or  8  wherein the material located within each tyre includes tyre side walls, coiled tyre tread or coiled conveyor belt, and/or particulate tyre/conveyor belt material.  
   
   
       10 . A unit as claimed in  claim 7  or  8  wherein the material located outside each tyre in the unit includes coiled tyre tread/conveyor belt and/or particulate tyre/conveyor belt material.  
   
   
       11 . A unit as claimed in any one of  claims 7  to  10  wherein a further fill material of sand, aggregate or crushed cobble stone is dispersed through the tyre or conveyor belt fill material.  
   
   
       12 . A unit as claimed in any one of the preceding claims wherein a retention element is provided to extend around a perimeter of the plurality of tyres.  
   
   
       13 . A unit as claimed in  claim 12  wherein the retention element extends continuously around the perimeter of the plurality of tyres.  
   
   
       14 . A unit as claimed in  claim 12  or  13  wherein the retention element is one or more lengths of tyre tread or conveyor belt.  
   
   
       15 . A unit as claimed in any one of  claims 12  to  14  wherein the retention element is located at the perimeter of the plurality of tyres in a manner such that, when located on ground in use, an undercut with respect to the outermost periphery of the unit is defined between the outside of the retention element and the ground.  
   
   
       16 . A unit as claimed in  claim 15  wherein the retention element has, or is sufficiently flexible to define, a transverse curvature that can match the curvature of an outer lateral face of each of the plurality of tyres to thereby define the undercut.  
   
   
       17 . A unit as claimed in any one of  claims 12  to  16  wherein each tyre in the unit is fixed to each adjacent tyre, and each tyre is fixed at one fixing point at least to the retention element.  
   
   
       18 . A unit as claimed in  claim 17  wherein each tyre is fixed using screwing, bolting, pinning and/or adhesive.  
   
   
       19 . A unit as claimed in any one of  claims 1  to  6  wherein a fill material is located within each tyre in use.  
   
   
       20 . A unit as claimed in  claim 19  wherein the fill material is located in voids within and between each tyre.  
   
   
       21 . A unit as claimed in  claim 19  or  20  wherein the fill material includes sand, aggregate or crushed cobble stone.  
   
   
       22 . A unit as claimed in  claim 21  wherein the fill material is, alternatively or additionally, tyre or conveyor belt material.  
   
   
       23 . A unit as claimed in  claim 22  wherein the fill material located within each tyre includes tyre side walls, coiled tyre tread or coiled conveyor belt, and/or particulate tyre/conveyor belt material.  
   
   
       24 . A unit as claimed in  claim 22  or  23  wherein the fill material located outside each tyre in the unit includes coiled tyre tread/conveyor belt, and/or particulate tyre/conveyor belt material.  
   
   
       25 . A unit as claimed in any one of  claims 7  to  11  further including a capping element located on top of the unit in use.  
   
   
       26 . A unit as claimed in  claim 25  wherein the capping element defines a continuous platform on the void former which is fastened to the unit and in use can support a human user, reinforcing mesh, or utilities pipework and/or ducting.  
   
   
       27 . A unit as claimed in  claim 25  or  26  wherein the capping element is a roll-formed sheet material.  
   
   
       28 . A unit as claimed in  claim 27  where the roll-formed sheet material is roll-formed steel which is optionally galvanised or coated.  
   
   
       29 . A unit as claimed in  claim 27  or  28  wherein the roll-formed sheet is corrugated.  
   
   
       30 . A unit as claimed in any one of the preceding claims wherein each tyre in the unit has an in-use upper sidewall removed therefrom.  
   
   
       31 . A concrete foundation including one or more units as defined in any one of the preceding claims.  
   
   
       32 . A foundation as claimed in  claim 31  that is a monolithic raft slab.  
   
   
       33 . A foundation as claimed in  claim 32  wherein, prior to forming the slab, a reinforcing mesh for the slab is located on top of the one or more units.  
   
   
       34 . A foundation as claimed in any one of  claims 31  to  33  that includes a plurality of units positioned to define a plurality of channels therebetween such that, when concrete is poured into those channels, beams are defined which project downwardly in the foundation in use.  
   
   
       35 . A foundation as claimed in  claim 34  wherein each beam is keyed into an undercut defined between the unit and the ground.  
   
   
       36 . A method for preparing a concrete foundation on ground, including the steps of: 
 (i) arranging on the ground one or more units as defined in any one of  claims 1  to  6 , absent the capping element;    (ii) in-filling the unit(s) with a fill material; and    (iii) covering each unit with a respective capping element.    
   
   
       37 . A method as claimed in  claim 36  wherein the fill material is located and is as defined in any one of  claims 19  to  24 .  
   
   
       38 . A method as claimed in  claim 36  or  37  wherein, after step (iii), concrete is poured over the prepared concrete foundation to cover the one or more units and to fill any spaces therebetween.  
   
   
       39 . A method as claimed in  claim 38  wherein, after step (iii), and prior to concrete pouring, a reinforcing mesh is overlaid the one or more units, which is embedded in the concrete after concrete curing.  
   
   
       40 . A method as claimed in  claim 38  or  39  wherein reinforcing is arranged in one or more channels defined between adjacent units, which reinforcing is embedded in the concrete after concrete curing.  
   
   
       41 . A method as claimed in any one of the preceding  claims 36  to  40  wherein the capping element is a roll-formed sheet material which is cut to size and then positioned on each unit prior to overlaying the reinforcing mesh.  
   
   
       42 . A method of forming a unit as defined in any one of  claims 1  to  6  including the steps of: 
 arranging the plurality of tyres side-by-side;    sizing and then locating the capping element on the unit.    
   
   
       43 . A method as claimed in  claim 42  wherein, after arranging the tyres and prior to locating the capping element, a retention element as defined in any one of  claims 12  to  18  is fastened at the perimeter of the plurality of tyres.  
   
   
       44 . A method as claimed in  claim 42  or  43  wherein, prior to locating the capping element on the unit, the unit is filled with a fill material as defined in any one of  claims 19  to  24 .  
   
   
       45 . A method as claimed in any one of  claims 42  to  44  wherein the step of locating the capping element on the unit includes a further step of fixing the capping element to the unit using screws, bolts, pins and/or adhesive.  
   
   
       46 . A method of forming a unit as defined in any one of  claims 7  to  11  including the steps of: 
 arranging the plurality of tyres side-by-side;    in-filling the unit with a fill material formed from tyre or conveyor belt material.    
   
   
       47 . A method as claimed in  claim 46  wherein, after arranging the tyres and prior to in-filling the unit with the fill material, a retention element as defined in any one of  claims 12  to  18  is fastened at the perimeter of the plurality of tyres.  
   
   
       48 . A method as claimed in  claim 46  or  47 , further including the step of locating a capping element on the unit in a manner as defined in any one of  claims 42  to  45 .