This invention relates to insulated concrete form construction methods and walls and buildings constructed using insulated concrete forms.
Insulated concrete form (ICF) construction techniques typically involve fixing two foam forms a fixed distance apart and pouring concrete between the forms. After the concrete has set, the foam forms remain in place to provide insulation for the concrete structure. Reinforcing members, such as rebar or mesh, may be located in the gap between the forms before the pour to become embedded in the concrete and provide reinforcement to the structure after the concrete sets.
Foam forms for ICF construction typically have ties that hold the two foam layers a set distance apart during the concrete pour. An example of a suitable foam form are Nudura (trademark) forms, though other suitable forms are also commercially available comprising a high enough density and appropriate chemical formula to meet the fire requirements. While the present application only illustrates straight foam forms for straight walls comprising two planar rectangular foam layers for ease of illustration, forms for alternate wall configurations including angles, corners and curves may also similarly be used.
Multi-storey concrete structures have traditionally not been constructed using ICF due to the difficulties in maintaining alignment of the forms during the pour. While ICF is used for construction near ground level, inaccuracies in alignment tend to become exaggerated with each additional storey of construction making their use in multi-storey structures more problematic. Deviations in the forms during the pour require repairs to the foam and concrete structure that are difficult, time consuming and expensive.
One aspect of the difficulties faced in building multi-storey concrete structures using ICF construction techniques has been the lack of ready access to the outside of the structure during construction above the first storey. Another aspect of the difficulties faced in building multi-storey concrete structures using ICF construction techniques has been the difficulty in creating openings through the structure including openings to accommodate windows, doors, sliding doors, glass blocks. A further aspect of the difficulties faced in building multi-storey concrete structures using ICF construction techniques has been creating openings through the structure at upper storey locations where access to the outside of the structure during construction is limited.
Wooden frame openings are a standard residential construction technique used in wood frame residential structures that have been adapted for use in ICF structures. One method of creating openings using ICF construction techniques has been to cut the opening through the forms and create a wooden frame around the shape of the intended opening. After erecting the forms on a suitable base, the permanent wooden frame about the shape of the opening is inserted between the forms. The wooden frame is then braced and concrete poured in at the top of the forms to fill the wall. A waterproof membrane is typically applied over the frame and adjoining area of the forms to prevent moisture from entering the ICF structure. A limitation of this construction technique is that the wooden frame remains in the ICF structure.
An advantage of ICF structures in general is that they are not prone to rot or ingress of water into the structure. The use of a wooden frame may cause complications as wood may react with the concrete, rot over time, or allow ingress of water if the membrane is damaged. A further limitation of using permanent wooden frames is that voids may form in the concrete beneath the frame. A further limitation of using permanent wooden frames is that the portion of the ICF structure bounded by the wooden frame is not thermally sealed compared to the portion of the ICF structure bounded by the insulated forms. A further limitation of using permanent wooden frames is that some building codes restrict the use of wood in contact with concrete for concrete structures.
There is a need for a system and method of ICF construction for creating openings through a multi-storey concrete structure.
There is a further need for a system and method of ICF construction that creates openings through a multi-storey concrete structure without the need for a permanent wooden frame embedded in the structure.
In drawings which illustrate by way of example only a preferred embodiment of the invention,
a is an illustration of an ICF structure.
b is an isometric illustration of a set of ICF forms having an opening.
There is provided a method of constructing an insulated concrete form structure having a structure opening through the structure, the structure opening defined by form edges and opening forms bonded to a concrete core of the structure, the method comprising erecting a set of spaced apart forms on a base; positioning opening forms in the space between the forms around a form opening through the forms; securing the opening forms around the form opening; and, pouring concrete to fill the space between the forms, around the opening forms, to a top portion of the forms, creating the concrete core of the structure; whereby the opening forms bond to the concrete core, the opening forms and the form edges defining the structure opening.
The method may further comprise, while positioning the opening forms, leaving an opening forms gap at a lower portion of the forms opening; pouring a first pour of concrete to fill the space between the forms upto the gap of opening forms; positioning opening forms to close the opening forms gap and allowing the first pour of concrete to set; pouring a second pour of concrete to fill the space between the forms from the top of the first pour around the opening forms to a top portion of the forms.
Additionally, the method may comprise after pouring the first pour of concrete, agitating the concrete before positioning opening forms to close the opening forms gap. The agitator may be inserted through the opening forms gap to agitate the concrete.
Alternatively, the method may additionally comprise
There is provided an insulated concrete from structure having been constructed using the above methods.
There is provided an insulated concrete form structure having a structure opening through the structure, the structure opening defined by opening edges of the forms and opening forms bonded to a concrete core of the structure, the structure comprising a set of forms erected on a base; the forms spaced apart to define a gap-bounded by the forms; the gap filled with a concrete core; a forms opening through the forms and a concrete opening through the concrete core; a perimeter of the structure opening defined by the opening edges of the forms and a set of opening forms; the opening forms spanning the gap at the opening edges; one surface of the opening forms bonded to the concrete core and defining the concrete opening and an opposite surface of the opening forms defining the structure opening; whereby the opening forms insulate the concrete core and provide a moisture barrier between the concrete core and the structure opening.
The opening forms of the structure may further comprise ties affixed to the surface of the opening forms bonded to the concrete, and extending into and terminating in the concrete core; the ties bonded to the concrete core.
In
During construction, the forms 8, 10 are erected spaced apart on a base with the reinforcement located in the space between the forms 8, 10. Concrete may then be poured into the space between the forms 8, 10. Concrete agitators (not shown) may be used to remove voids from the fresh concrete. After the concrete has had sufficient time to cure and set to comprise a concrete structure, the forms 8, 10 may stay in place to provide insulation of the structure.
b is an isometric view and
In situations where the structure opening 14 is relatively wide, or its lower portion 12 is located relatively close to a lower portion of the forms 8, 10, it is desirable to utilise a two-step concrete pour as described below. In the embodiment illustrated in
The positioned opening forms 13, 17 are preferably braced using temporary bulkheads 25 (not shown in this Figure) affixed to the forms 8, 10 and optionally additional supports 26 (not shown in this Figure) across the structure opening 14. While it is not necessary to position the temporary bulkheads 25 for the upper opening form 17 at this time, it is desirable to do so to protect the opening form 17 from inadvertent concrete pour.
A first concrete pour may be made to a bottom portion of the opening forms 13 to either side of the structure opening 14 upto a pour line 11. It is desirable to size the opening forms 13 to extend past the structure opening 14 a width of the lower opening form 15 to be positioned in the lower portion 12 of the structure opening 14. In this fashion the lower portion of the opening forms 13 indicates a preferred level of the pour line 11.
Omitting the opening form 15 in a lower portion 12 of the structure opening 14 allows for visual inspection of the level of the concrete during the pour and to ensure no voids form in the concrete below the lower portion 12 of the structure opening 14. After completing the pour to the pour line 11, the concrete may be agitated by inserting a concrete agitator into the concrete accessible through the form opening 12.
After agitation the concrete below the lower portion 12 of the structure opening 14 is preferably dressed and leveled to provide a bonding surface to receive the opening form 15 to be positioned in the lower portion 12 of the structure opening 14. After the concrete has been dressed and leveled, the opening form 15 may be positioned on the concrete surface in the lower portion of the structure opening 14 as illustrated in
After the concrete of the first pour has sufficiently set, a support 26 may be erected using the opening form 15 positioned in the lower portion of the structure opening 14 as a base to support the opening form 17 positioned in the upper portion of the structure opening 14. After completing bracing, a second concrete pour may fill the space between the forms 8, 10 from a level of the first pour to an upper portion of the forms 8, 10 around the structure opening 14.
Opening forms 13, 15 and 17 may preferably be sized from scrap cuttings of forms 8, 10 used at a building site. For instance, forms 8, 10 may be cut to create the forms opening 12. The cutting may be sized to create opening forms 13, 15 and 17. Preferably the opening forms 13, 15 and 17 are sized in length to span lengths of the forms opening 12 in a single piece and sized in width to form a friction-fit engagement with the forms 8, 10.
Preferably, opening forms 13, 15 and 17 include tie remnants affixed to one surface of the opening forms 13, 15 and 17. The forms 8, 10 are typically joined by ties affixed to a surface of each form 9, 10 and spanning the space between the forms. When cutting the forms, it is preferably to cut the form ties at roughly a mid-point along the length of the ties to leave a tie remnant on each form cutting.
When positioning the opening forms 13, 15 and 17, it is preferable to locate the surface covered in tie remnants facing the space between the forms 8, 10. In this fashion both the surface of the opening forms 13, 15 and 17 and the tie remnants bonds to the concrete core 16.
If a stucco exterior is being applied to the forms 8, 10, a mesh 18 may be fitted in with the opening forms 13, 15 and 17 as illustrated in
The ICF method described may be modified according to a particular ICF structure. In the case where the structure opening is narrow, or is located near an upper portion of the forms 8, 10, it may not be necessary to conduct a two step pour.
This application is a continuation application of application Ser. No. 11/872,894, filed Oct. 16, 2007, which is incorporated herein by reference.
Number | Date | Country | |
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Parent | 11872894 | Oct 2007 | US |
Child | 13368868 | US |