GB2445943A

GB2445943A - ICF web

Info

Publication number: GB2445943A
Application number: GB0701381A
Authority: GB
Inventors: Malcolm Howorth; Graeme Howorth; Peter B Dunford
Original assignee: ICF Technology Ltd
Current assignee: ICF Technology Ltd
Priority date: 2007-01-25
Filing date: 2007-01-25
Publication date: 2008-07-30
Also published as: GB0701381D0

Abstract

The invention relates to an insulated concrete form (ICF) web, used to connect expanded polystyrene sheets together to create a building block, in insulated concrete form wall structures. The cavity which the webs create is then subsequently filled with concrete to form a monolithic wall structure. The ICF web comprises a uniform structural loading surface B (firring web) so as to enable external and internal load fixings at any point along the fining Piece B without distortion taking place within the Web body K (L figure 2) leading to structural failure. The provision of Ribs within the Web structure E enable eccentrically fixed loads at B to be safety transmitted to the cavity D where the Web section K (L figure 2) is encased in concrete. The strength of the fining Piece B is preferably further enhanced by the provision of Tabs A which extend into the cavity of the Form D and become embedded in the concrete.

Description

ICF WEB

The invention relates to the polymer Webs that are used to connect Expanded Polystyrene (EPS) sheets together to create a building block (referred to as Form or Forms in the remainder of this document) in some Insulated Concrete Form (ICF) wall structures. The cavity which the Webs create is filled with concrete to form a monolithic wall structure, the EPS remaining to provide insulation.

Such Webs are a proven method of construction for ICF's, and come in a variety of shapes and sizes to suit the manufacturer's requirements, and many claim, once the cavity has been filled with concrete and cured, that they are able to support external loads once fixings have been screwed into flat sections on the face, or near to the face of the EPS, which are commonly known as Fining Pieces. However, through Finite Element Analysis, we have learnt that other Web designs cannot provide a uniform level of support throughout the length of the Firring Piece, resulting in uneven stresses throughout the web structure which would, if left unchecked, result in failure of the web.

The object of this invention is to produce a Web that addresses these problems by providing a web structure that distributes the loads from the fining pieces uniformly to the rest of the Web, and not isolating forces in one area.

Accordingly, this invention will allow commercially-available exterior cladding systems to be fixed to any part of the Fining piece due to the use of Ribs in a lattice-girder design, connecting the fining piece to the inner part of the Web, which also feature Tabs at the ends of the inner part of the Web that become embedded within the concrete core.

Preferably, the base material will be made of a mouldable polymer, such as Talc Filled Polypropylene, but extrudable polymers could be used with the correct plasticiser. These higher strength materials allow fixing of heavier loads such as those associated with tile hanging and resist long term deformation and creep.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings which: FIGURE 1 shows a front and plan view of our Web from a standard Form FIGURE 2 shows a front and plan view of our Web from a FloorForm FIGURE 3 a section through a Form, indicating the position of the Web within the Form FIGURE 4 is a section showing part on our ICF wall with external cladding applied.

FIGURE 5 shows a typical side view (vertical section) of the Form cavity closer with a window frame and ciii in position, along with internal and external finishes; FIGURE 6 is a section through a FloorForm indicating the purpose of the FloorFonn Web (fig.2) tabs (A) in securing the exterior EPS wall (F) to the concrete within the cavity section (D).

Figures 1 & 2 -The Webs are shown in Figures 1 & 2, Figure 1 detailing the Standard Web and Figure 2 detailing the FloorForm Web. The main body of the Web (K) is symmetrical both vertically and horizontally around the mid-point and is divided into two distinct areas; those that are embedded into the EPS wall (Figure 3 item C) and the central part (Figure 3 item D) which is within the cavity which receives the concrete. The Web (K) has two identical external faces which are referred to as Firring Pieces (B) which allow finishes to be mechanically fixed to the Web (K) and their loads transferred to the central part of the Web (K), transmitting the load into the hardened concrete within the cavity (D). As fixing points for external/internal finishes are not uniform, reinforcement Ribs (E) allow the webs to transfer loads from the Firring Pieces (B) throughout their length and transfer these to the core (D). To ensure these forces are anchored to the concrete within the cavity (D) at the extremities of the Web (K), Tabs (A) are provided which become embedded to the concrete.

Figure 2 shows the main body of the FloorForm Web (L). As with Web (K), the FloorForm Web (L) has two sections (C) which are embedded within the EPS (Figure 6 item Q). However, the FloorForm is filled with concrete to form a ledge (M) within the cavity section (D) to accept floor constructions (Figure 6 item P).

Further standard!CF Forms are then placed above the FloorForm and the cavity filled, whereby encapsulating Tabs (A) in concrete which allow the forces applied to the Fining Piece (B) to be transmitted to the concrete core (D) Figure 3-This shows a side view of a standard Form with the two walls of EPS (F) shown either side of the web (K) with the web parts (C) being embedded within the EPS wall. Tabs (A) are visible within the core of the Form which is filled with concrete.

Figure 4-This shows a vertical cross-section of the Form at window head level (J) with vertical plain clay tiling (G) fixed to the embedded Fining piece (B) [not seen] via timber battens (H). As can be seen, the vertical spacing of the timber battens (H) is not even or symmetrical about the centreline (N) of the Web (K), creating non-uniform loadings on the web (K) Figure 5-This shows an isometric view of the standard Web (K) with all points previously mentioned above and shows the lattice-girder detail of part (C) of the web.

Figure 6-This shows the FloorForm (L) acting as the support for a concrete floor structure (P) with Tabs (A) being encapsulated within the cavity void left by the floor construction (P). Part standard Forms are shown above and below the FloorForm with their protruding Tabs (A). /.

Claims

I. An ICF Web when used in Insulating Concrete Forms (ICF) provides a Fining Piece capable of transmitting unequally spaced loads fixed to the Firring Piece, back to the concrete core, preventing isolated failure of the Web.
2. An ICF Web when used as claimed in Claim 1, which includes reinforcement Ribs to the web in a lattice-girder arrangement to transfer the loads from the Fining Piece through the Ribs to the central part of the Web that is encapsulated in the concrete core.
3. An ICF Web when used as in Claim 1 or Claim 2, which incorporates Tab protrusions at the internal extremities of the web body to secure the Web firmly into the concrete core to prevent distortion of the web in these areas and thereby prevent failure of the Webs.
4. An ICF Web when used as in Claim 1, Claim 2 or Claim 3, which incorporates reinforcement of the web design by inclusion of thickenings protruding from the normal plane of the web to prevent distortion of the web in these areas and thereby prevent failure of the Webs.
5. An ICF Web when used as in Claims I to 4, which is moulded using a Talc Filled Polypropylene for additional strength and long term creep resistance.