Abstract:
A web ( 10 ) for an insulated concrete form ( 20 ) comprises a pair of opposed web elements ( 12 ) and a pair of connectors ( 14 ). The web elements ( 12 ) and the connectors ( 14 ) are provided with mutually interengaging formations, such as a non-circular tube ( 12.1 ) and V-shaped hook formations ( 14.1 ), whereby the web element ( 12 ) and the connectors ( 14 ) are rigidly connected together in a plane to form a stable structure.

Description:
FIELD OF THE INVENTION 
     This invention relates to an insulated concrete form and, in particular, to a web for an insulated concrete form. 
     BACKGROUND OF THE INVENTION 
     Insulated concrete forms allow concrete foundations and walls to be poured and insulated at the same time. Each form comprises a pair of spaced foam panels separated by webs extending between the panels. 
     The webs are important in that they should be sturdy enough to provide a form that is stable and strong and yet does not interfere with the pouring of the concrete into the form. 
     It is accordingly an object of the present invention to provide a web for an insulated concrete form which satisfies the above requirements. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided a web for an insulated concrete form comprising a pair of opposed web elements and a pair of connectors for connecting the web elements together in spaced relationship, the web elements and the connectors being provided with mutually interengaging formations whereby the web elements and the connectors are rigidly held together in a plane. 
     Each web element may comprise a flat strip provided with a non-circular tube on one side forming said mutually interengaging formation on the web element for engaging with one of the connectors. 
     Each connector may comprise a steel bar and wherein said mutually interengaging formations on the connector comprise V-shaped or U-shaped hook formations at its opposite ends, respectively, for engaging with the non-circular tube on each of said opposed web elements. 
     Also according to the invention there is provided an insulated concrete form comprising a pair of opposing panels of a thermal insulating material which are connected together in spaced relationship by means of a plurality of the webs as described. 
     Further objects and advantages of the invention will become apparent from the description of preferred embodiments of the invention below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
     FIG. 1 is an end view of a web element for an insulated concrete form; 
     FIG. 2 is a plan view of a connector for connecting a pair of the web elements of FIG. 1 together to form a web; 
     FIG. 3 is a plan view showing a pair of the web elements of FIG. 1 connected together by two of the connectors of FIG. 2 to form a web; 
     FIG. 4 is a perspective view of an insulated concrete form which has been manufactured using five of the webs of FIG. 3; 
     FIG. 5 is another perspective view of the insulated concrete form of FIG. 4 with a part of the side cut away to show the web; and 
     FIG. 6 is a close-up view of the insulated concrete form of FIG. 4 showing how the web is embedded. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In FIG. 3, reference numeral  10  generally indicates a web comprising a pair of web elements or furring strips  12  which are connected together by means of a pair of connectors  14 . 
     An end view of a furring strip  12  is shown in FIG.  1 . It is of a high density plastic. On one side of the strip  12 , the plastic is shaped into a diamond-shaped tube  12 . 1 . Extending from the tube  12 . 1  is a flat section  12 . 2  which is 1.8″ in width. At the opposite side of the flat section  12 . 2 , the plastic is formed into a bar  12 . 3  which is 0.975″ in width. As shown, the bar  12 . 3  is flat on the outside and has six ribs  12 . 4  on the inside, each rib  12 . 4  being ⅛″ deep. 
     A connector is shown in FIG.  2 . It comprises a bar of 9 gauge galvanised steel. 
     The connector  14  is formed into a V-shaped hook  14 . 1  at each end. The hooks  14 . 1  are inserted into the diamond-shaped tube  12 . 1  and engage with the opposite corners of the diamond shape, as shown in FIGS. 1 and 3. This provides for rigidity and stability in the plane of the web  10 , i.e. the strips  12  cannot move or rotate relative to each other. Once the hooks  14 . 1  are inserted, they lock the connector  14  into place and are difficult to remove from the diamond-shaped tube  12 . 1 . 
     An insulated concrete form  20  is formed using several of the webs  10 , as shown in FIGS. 4 to  6 . 
     The form  20  comprises a pair of opposing panels  22  of expanded polystyrene connected together in spaced parallel relationship by the webs  10 . The strips  12  of the webs  10  are embedded in the polystyrene during the moulding of each panel  22 . For this purpose, the mould that is used for producing the panels  22  is provided with a long prong for each furring strip  12 . The tube  12 . 1  slides over the prong to locate each furring strip  12  in position in the mould. 
     The mould is then closed and the mould cavity is filled with expanded polystyrene which then completely encases the furring strips  12 . Only the openings of the tubes  12 . 1  are visible after the moulding is completed, as shown in FIG.  6 . 
     The furring strip  12  is embedded so that the flat side of the bar  12 . 3  is about ½″ from the outside wall of the panel  22 . Since the steel connector  14  is engaged with the plastic tube  12 . 1 , which only has minimal thermal conductivity, and the bar  12 . 3  is located ½″ away from the outside wall of the panel  22 , a full thermal break is obtained. Therefore, the conductivity of heat or cold through a wall constructed with the insulated concrete forms  20  is effectively counteracted. 
     After moulding, the panels  22  are joined together by the connectors  14  which are inserted into the diamond-shaped tubes  12 . 1 , as described above. The form  20  can therefore easily be assembled, either on or off the job site, which allows for larger shipments of the form  20 , saving delivery costs. The connection of the connectors  14  may also be effected while the panels  22  are still warm after ejection from the mould. 
     The strip  12  is manufactured (extruded) in continuous form and is then cut into the required length, depending on the depth of the form  20  that is being made. 
     As shown, the form  20  is provided with tongue  20 . 1  and groove  20 . 2  formations for easy placement of adjacent forms  20 . 
     In use, the forms  20  are placed on the foundation of a building being constructed. Steel reinforcing bars are placed in the forms  20  and the forms  20  are then filled with concrete. The web  10  provides for faster flow of the concrete because it does not form an obstruction inside the form  20 , thus counteracting the formation of weak spots, such as air pockets. 
     The form  20  can also be used for forming the foundation and for this purpose can be provided in a larger size than a form intended for use in forming a wall. The form  20  can be provided for a variety of wall and foundation widths, ranging from 4″ wide to 32″ wide. 
     The form  20  also allows for stucco applications to be uniform in density and counteracts cracking of the stucco because the web elements  12  are completely encased within the form panels  22 . 
     The flat outside of the bar  12 . 3  on the furring strip  12  is to accommodate the attachment of interior and exterior sheeting to the walls, while the ribs  12 . 4  improve the strength of the bar  12 . 3  and also provide for more securely embedding the bar  12 . 3  inside the panel  22 . 
     While only preferred embodiments of the invention have been described herein in detail, the invention is not limited thereby and modifications can be made within the scope of the attached claims.