Insulated concrete form

Information

  • Patent Grant
  • 6170220
  • Patent Number
    6,170,220
  • Date Filed
    Friday, January 16, 1998
    28 years ago
  • Date Issued
    Tuesday, January 9, 2001
    25 years ago
  • Inventors
  • Examiners
    • Stephan; Beth A.
    • Glessner; Brian E.
    Agents
    • Needle & Rosenberg, P.C.
Abstract
An insulated concrete structure including at least one longitudinally-extending side panel and at least one web member partially disposed within the side panel. The web member extends from adjacent the external side of the side panel through and out of the interior surface of the side panel. The first embodiment of the present invention uses opposed side panels that form a cavity therebetween into which concrete is poured and cured. The second embodiment uses a single side panel as a form, onto which concrete is poured. Once the concrete cures on the single side panel, it is used as a tilt-up wall, floor, or roof panel.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention encompasses a building component used to make insulated concrete forms and, more particularly, to a system that can be used to make cast-in-place walls using two opposed side panels or tilt-up walls using a single side panel.




2. Background Art




Concrete walls in building construction are most often produced by first setting up two parallel form walls and pouring concrete into the space between the forms. After the concrete hardens, the builder then removes the forms, leaving the cured concrete wall.




This prior art technique has drawbacks. Formation of the concrete walls is inefficient because of the time required to erect the forms, wait until the concrete cures, and take down the forms. This prior art technique, therefore, is an expensive, labor-intensive process.




Accordingly, techniques have developed for forming modular concrete walls, which use a foam insulating material. The modular form walls are set up parallel to each other and connecting components hold the two form walls in place relative to each other while concrete is poured therebetween. The form walls, however, remain in place after the concrete cures. That is, the form walls, which are constructed of foam insulating material, are a permanent part of the building after the concrete cures. The concrete walls made using this technique can be stacked on top of each other many stories high to form all of a building's walls. In addition to the efficiency gained by retaining the form walls as part of the permanent structure, the materials of the form walls often provide adequate insulation for the building.




Although the prior art includes many proposed variations to achieve improvements with this technique, drawbacks still exist for each design. The connecting components used in the prior art to hold the walls are constructed of (1) plastic foam, (2) high density plastic, or (3) a metal bridge, which is a non-structural support, i.e., once the concrete cures, the connecting components serve no function. Also, these procedures also cannot be used to make floors or roof panels.




One embodiment of a connecting component is disclosed in U.S. Pat. No. 5,390,459, which issued to Mensen on Feb. 21, 1995 and which is incorporated herein by reference. This patent discloses “bridging members” that comprise end plates connected by a plurality of web members. The bridging members also use reinforcing ribs, reinforcing webs, reinforcing members extending from the upper edge of the web member to the top side of the end plates, and reinforcing members extending from the lower edge of the web member to the bottom side of the end plates. As one skilled in the art will appreciate, this support system is expensive to construct, which increases the cost of the formed wall.




SUMMARY OF THE INVENTION




The disadvantages of the prior art are overcome by the present invention, which provides an insulated concrete form comprising at least one longitudinally-extending side panel and at least one web member partially disposed within the side panel. The web member extends from adjacent the external surface of the side panel through and out of the interior surface of the side panel. Two embodiments of the present invention are described herein. The first embodiment uses opposed side panels that form a cavity therebetween into which concrete is poured and cured. The second embodiment uses a single side panel as a form, onto which concrete is poured. Once the concrete cures and bonds to the side panel, it is used as a tilt up wall, floor, or roof panel.




In the first embodiment, the web member is molded into a side panel, in which the web member projects beyond the interior surface of the side panel and facing, but does not touch, an opposing, identical side panel. The first embodiment also uses a connector which attaches to the two opposing web members, thereby bridging the gap between the two side panels for positioning the side panels relative to each other. The connectors preferably have apertures to hold horizontally disposed re-bar. The connectors also have different lengths, creating cavities of different widths for forming concrete walls having different thicknesses. The connectors are interchangeable so that the desired width of the wall can be set at the construction site.




The web member is also molded into a side panel for the second embodiment so that a portion of the web member projects beyond the interior surface of the side panel. In use, the side panel is first horizontally disposed so that the interior surface and portion of the web member extending therethrough are positioned upwardly. Forms are placed around the periphery of the side panel and concrete is then poured onto the interior surface. Once the concrete cures and bonds with the interior surface and the portion of the web member extending therethrough, the side panel and connected concrete can be used as a tilt-up wall, flooring member, or roof panel.











BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS





FIG. 1

is a perspective view of the first embodiment of the present invention.





FIG. 2

is a perspective side view of a

FIG. 1

taken along line


2





2


.





FIG. 2A

is an alternative view of

FIG. 2

showing concrete disposed between the two opposed side panels.





FIG. 3

is a perspective view of one side panel shown in

FIG. 1

, in which three web members show four attachment points extending through the interior surface of the side panel, two web members show two connectors attached to attachment points, and one web member shows two connectors and another web member attached thereto.





FIG. 4

is a perspective view of the connector in FIG.


3


.





FIG. 5

is a perspective view of the side panel of the second embodiment of the present invention, in which a portion of the side panel is cut away to shown the body portion of the web member partially disposed therein.





FIG. 5A

is an alternative view of

FIG. 5

showing concrete disposed on and connected to the side panel.











DETAILED DESCRIPTION OF THE INVENTION




The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. As used in the specification and in the claims, “a” can mean one or more, depending upon the context in which it is used. The preferred embodiment is now described with reference to the figures, in which like numbers indicate like parts throughout the figures.




As shown in FIGS.


1


-


5


A, the present invention comprises a concrete form system


10


used for constructing buildings. A first embodiment of the present invention, shown in

FIGS. 1

,


2


, and


2


A, comprises at least two opposed longitudinally-extending side panels


20


, at least one web member


40


partially disposed within each of the side panels


20


, and a connector


50


disposed between the side panels


20


for connecting the web members


40


to each other. As shown in

FIG. 2A

concrete C is poured between the side panels


20


so that it bonds with the side panels


20


and the web members


40


. A second embodiment of the present invention, which is discussed in more detail below and shown in

FIGS. 5 and 5A

involves using a single side panel


20


that bonds with the concrete C, instead of using opposed side panels


20


on both sides of the concrete.




Each side panel


20


has, a top end


24


, a bottom end


26


, a first end


28


, a second end


30


, an exterior surface


32


, and an interior surface


34


. The presently preferred side panel


20


has a thickness (separation between the interior surface


34


and exterior surface


32


) of approximately two and a half (


2{fraction (1/2)}) inches, a height (separation between the bottom end 26 and the top end 24) of sixteen (


16) inches, and a length (separation between the first end


28


and second end


30


) of forty-eight (48) inches. The dimensions can be altered, if desired, for different building projects, such as increasing the thickness of the side panel


20


for more insulation. Half sections of the side panels


20


can be used for footings.




Referring now to

FIGS. 1 and 2

, the interior surface


34


of one side panel


20


faces the interior surface


34


of another side panel


20


in the first embodiment and the opposed interior surfaces


34


are laterally spaced apart from each other a desired separation distance so that a cavity


38


is formed therebetween. Concret—in its fluid state—is poured into the cavity


38


and allowed to cure (i.e., harden) therein to form the wall as shown in FIG.


2


A. Preferably, the opposed interior surfaces


34


are parallel to each other. The volume of concrete C received within the cavity


38


is defined by the separation distance between the interior surfaces


34


, the height of the side panels


20


, and the length of the side panels


20


.




The side panels


20


are preferably constructed of polystyrene, specifically expanded polystyrene (“EPS”), which provides thermal insulation and sufficient strength to hold the poured concrete C until it substantially cures. The formed concrete wall using polystyrene with the poured concrete C has a high insulating value so that no additional insulation is usually required. In addition, the formed walls have a high impedance to sound transmission.




As best shown in

FIGS. 3 and 5

, the interior surface


34


preferably includes a series of indentations


36


therein to enhance the bond between the side panels


20


and concrete. To improve further the bond between the side panels


20


and the concrete C poured in the cavity


38


, a portion of each of the web members


40


formed in the side panels


20


extends through the interior surface


34


of the side panels


20


into the cavity


38


. A portion of each web member


40


is integrally formed within one side panel


20


and is also cured within the concrete C so that the web member


40


strengthens the connection between the side panel


20


and the concrete. That is, since the web member


40


is an integral part of the side panel


20


, it “locks” the side panel


20


to the concrete C once the concrete C is poured and cures within the cavity


38


.




As shown in FIGS.


1


-


3


and


5


, each side panel


20


has at least one web member


40


formed into it. Preferably, the each web member


40


formed within a side panel


20


is separated a predetermined longitudinal distance, which is typically eight (8) inches. Based on the preferred length of the side panel


20


of forty-eight inches, six web members


40


are formed within each side panel


20


, as shown in

FIGS. 3 and 5

.




The portions of each web member


40


that extend through the interior surface


34


of the side panel


20


form attachment points


44


. The attachment points


44


are disposed within the cavity


38


and spaced apart from the interior surface


34


of the side panels


20


. As discussed below, the connectors


50


detachably engage two attachment points


44


on opposed web members


40


, which position the interior surfaces


34


of the side panels


20


at a desired separation distance and support the side panels


20


when the concrete is poured into the cavity


38


.




Referring now to

FIG. 3

, each web member


40


also preferably has an end plate


42


disposed adjacent the exterior surface


32


of the side panel


20


. The end plates


42


are substantially rectangular in plan view. Each end plate


42


of the web members


40


are completely disposed within a portion of one respective side panel


20


. That is, the end plates


42


are located slightly below the exterior surface


32


of, or recessed within, the side panel


20


, preferably at a distance of one-quarter (¼) of an inch from the exterior surface


32


. This position allows for easily smoothing the surface of the side panels


20


without cutting the end plate


42


should the concrete, when poured, create a slight bulge in the exterior surface


32


of the side panels


20


. Alternatively, the end plates


42


can abut the exterior surface


32


of panels. It is also preferred in the first embodiment that each end plate


42


is oriented substantially upright and disposed substantially parallel to the exterior surface


32


of the side panel


20


.




Similar to the end plate


42


, the attachment points


44


are also oriented substantially upright so that one attachment point


44


is disposed above another attachment point


44


. As best shown in

FIGS. 2 and 3

, each of the web members


40


has four spaced-apart attachment points


44


, in which the attachment points


44


for each web member


40


are vertically disposed within the cavity


38


in a substantially linear relationship. The attachment points


44


are placed in two groups—a top group of two attachment points


44


and a bottom group of two attachment points


44


. Adjacent attachment points


44


in the two groups are spaced apart a first distance from each other, preferably approximately two and an eighth (2⅛) inches apart between center points. In addition, the closest attachment points


44


of the two groups, i.e., the lowermost attachment point


44


of the top group and the uppermost attachment point


44


of the bottom group, are spaced apart a second distance from each other. The second distance, which is approximately six (6) inches in the preferred embodiment, is more than double and almost triple the first distance. As one skilled in the art will appreciate, the number of attachment points


44


used for each web member


40


can be varied based on factors such as the dimensions of the side panels


20


and the wall strength or reinforcement desired.




The design of the attachment points


44


is an improvement over prior art systems, which lack multiple mounting points for attaching an interconnecting device. The side panels


20


and web members


40


in the present invention can be cut horizontally over a wide range of heights to satisfy architectural requirements, such as leaving an area for windows, forming odd wall heights, and the like, and still have at least two attachment points


44


to maintain structural integrity of the wall. Prior art systems, in contrast, lose structural integrity if cut horizontally, thus requiring extensive bracing to resist collapsing when concrete is poured into the cavity


38


between the panels.




Referring again to

FIGS. 1 and 2

, the attachment points


44


of the web members


40


extend into the cavity


38


and the attachment point


44


of each web member


40


formed within one side panel


20


is spaced apart from the attachment points


44


of the web members


40


formed within the opposed side panel


20


. Thus, the web members


40


preferably do not directly contact each other; instead, each attachment point


44


independently engages the connector


50


that interconnects the web members


40


and, accordingly, the side panels


20


.




Referring now to

FIG. 4

, the connector


50


has opposed ends


52


and a length extending therebetween. The ends


52


of the connector


50


are of a shape to complementarily and removably engage the attachment point


44


of two respective web members


40


within opposed panels. As best shown in

FIG. 5

, the attachment point


44


is substantially rectangular and flat and, as best shown in

FIG. 4

, each end


52


of the connector


50


has a track


54


into which the rectangular member is slidably received.




To vary the width of the cavity


38


(i.e., the separation between the interior surfaces


34


of the opposed side panels


20


), different connectors


50


can have varying lengths. The width of the cavity


38


can be two (2), four (4), six (6), eight (8) inches or greater separation. Different connectors


50


are sized accordingly to obtain the desired width of the cavity


38


. Also, as one skilled in the art will appreciate, the fire rating, sound insulation, and thermal insulation increase as the width of the cavity


38


, which is filled with concrete, increases.




Referring now to

FIGS. 2 and 4

, the connectors


50


also preferably define an aperture


56


of a size to complementary receive a re-bar (not shown) therein. The re-bar provides reinforcing strength to the formed wall. The diameter of the re-bar can be one quarter (¼) inch or other dimension as required for the necessary reinforcement, which depends on the thickness of the concrete wall and the design engineering requirements. The connectors


50


preferably have two apertures


56


and re-bar can be positioned in either both of the apertures


56


before the concrete is poured into the cavity


38


. The apertures


56


can be designed so that the re-bar is securably snapped into place for ease of assembly.




The web members


40


and connectors


50


are preferably constructed of plastic, more preferably high-density polyethylene, although polypropylene or other suitable polymers may be used. Factors used in choosing the material include the desired strength of the web member


40


and connector


50


and the compatibility of the web member


40


with the material used to form side panels


20


. Another consideration is that the end plates


42


should be adapted to receive and frictionally hold a metal fastener, such as a nail or screw, therein, thus providing the “strapping” for a wall system that provides an attachment point


44


for gypsum board (not shown), interior or exterior wall cladding (not shown), or other interior or exterior siding (not shown). Thus, the web members


40


function to align the side panels


20


, hold the side panels


20


in place during a concrete pour, and provide strapping to connect siding and the like to the formed concrete wall.




One skilled in the art will appreciate that a plurality of side panels


20


can be longitudinally aligned to form a predetermined length and be vertically stacked to form a predetermined height. For example, as shown in

FIG. 1

, the first end


28


of one side panel


20


abuts the second end


30


of another side panel


20


and the bottom end


26


of one side panel


20


is disposed on the top end


24


of another side panel


20


. Thus, a series of side panels


20


can be aligned and stacked to form the concrete system


10


into which concrete C is poured to complete the wall. One consideration, however, is that the side panels


20


are not vertically stacked too high and filled at one time so that the pressure on the bottom side panel


20


is greater than the yield strength of the web members


40


or EPS side panels


20


. Instead, the stacked wall can be filled and cured in stages so that the pressure is not excessive on the lower side panels


20


.




To facilitate the stacking of the components, the side panels


20


are optionally provided with a series of projections


35


and indentations


37


that complementarily receive offset projections


35


and indentions


37


from another side panel


20


. The projections


35


and indentations


37


in the adjacent side panels


20


mate with each other to form a tight seal that prevents leakage of concrete during wall formation and prevents loss of energy through the formed wall.




Still referring now to

FIG. 1

, the present invention also uses comer sections


39


.




Preferably, each comer section


39


forms a substantially right angle and concrete C is also poured into the comer section similar to the other sections of the concrete form system


10


. Forty-five degree angle comer sections can also be used. Thus, the formed concrete wall is contiguous for maximum strength, as opposed to being separately connected blocks. Still another embodiment of the present invention, which is not shown, uses non-linear side panels


20


so that the formed wall has curvature instead of being straight.




The first embodiment of the present invention is an improvement over the prior art. Although other systems use connector


50


elements, the prior art lacks a web member


40


having an end plate


42


, which provides a nailing/screwing strip adjacent the exterior surface


32


of the side panel


20


, and has an attachment point


44


or similar connection projecting into the cavity


38


adjacent the interior surface


34


. Moreover, the present invention uses less plastic and is, therefore, less expensive to manufacture.




Furthermore, in prior art systems, the panels are made so that large, thick, plastic connector elements slide down in a “T” slot formed within the inside surface of the panel itself. These prior art designs are structurally weak and the construction workers in the field have substantial difficulty avoiding breaking the panels while sliding the connector


50


element into place. Additionally, the prior art panels can break off from the cured concrete if any “pulling” occurs while mounting sheetrock or other materials onto the outer side of the panel. The present invention provides a stronger “interlocking” system between the side panels


20


, the web member


40


, and the connectors


50


, which are imbedded within concrete in the cavity


38


.




Referring now to

FIGS. 5 and 5A

the second embodiment of the present invention uses a single side panel


20


to construct the insulated concrete form, unlike the first embodiment that uses opposed side panels


20


. The side panel


20


is horizontallydisposed so that the attachment points


44


extend upwardly. The interior surface


34


of the side panel


20


becomes the surface onto which concrete C is poured. Forms (not shown) are placed around the of the periphery, namely, the top end


24


, bottom end


26


, first end


28


, and second end


30


of the side panel


20


, to prevent the fluid concrete C from leaking off of the interior surface


34


. Once the concrete C hardens by curing, the forms are removed and the side panel


20


and cured concrete slab creates a concrete structure shown in FIG.


5


A. Unlike the first embodiment, only one side panel


20


is used and the portion opposite the side panel


20


is exposed to atmosphere, instead of contacting another, second side panel.




The concrete slab maintains its relative position against the interior surface


34


of the side panel


20


by the attachment points


44


of the web member


40


. That is, by projecting beyond the interior surface


34


of the side panel


20


, the web members


40


anchor the side panel


20


to the concrete slab. The connectors


50


can also be connected to the attachment points


44


to increase the surface area to which the concrete bonds. If the connectors


50


are the incorrect length, then they can easily be cut to the proper dimension at the construction site. Furthermore, re-bar can be positioned in the apertures


56


of the connectors


50


prior to pouring the concrete to strengthen the formed concrete structure.




The concrete structure, after curing, can be tilted upright so that concrete is on one side and the side panel


20


on the other side. In construction terminology, the concrete structure is called a “tilt-up” concrete wall. No prior art system has the ability to form such a concrete structure. The concrete structure can also be used as an insulated concrete floor, in which the panels are poured on the ground and after the concrete cures, placed on top of the tilt-up walls or the cast-in-place walls of the first embodiment. The second embodiment of the present invention can also be used to create roof panels. No insulated concrete form system exists in the prior art that can be used for tilt-up concrete walls, roof panels, or flooring because the prior art does not have a member extending partially beyond the interior surface of the side panel, but not extending all the way to a second, opposed panel. Nor is there a prior art form system that can be used for floor/ceiling and roof panels which can be cast as separate structural “panels” on the ground, and then lifted up to be placed on top of walls to form floors/ceilings or roofs.




Furthermore, the second embodiment of the present invention can be used to construct an entire building made of insulated concrete walls (“cast in place” or “til-tup”), floors, ceilings, and roof panels. The present invention is a major advancement in technology because no prior art concrete form system can build an entire building. The present invention additionally improves the speed of construction and lowers cost compared with the prior art.




Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention except as and to the extent that they are included in the accompanying claims.



Claims
  • 1. A method of constructing a concrete structure, comprising the steps of:a. disposing an interior surface of one side panel upright and substantially horizontal, said one side panel including a web member partially disposed therein so that a portion of said web member extends through the interior surface thereof, wherein said web member is constructed of a plastic comprising high-density polyethylene or polypropylene; b. pouring fluid concrete onto the interior surface of said one side panel so that the portion of said web member that extends through the interior surface of said one side panel is disposed within said poured concrete; and c. allowing said poured concrete to substantially cure so that said poured concrete becomes a concrete slab having a first side contacting the interior surface of said one side panel and an opposed second side wherein the portion of said web member that extends through the interior surface of said one side panel is disposed within said concrete slab to assist in maintaining contact between said concrete slab and said one side panel so that said joined concrete slab and one side panel become a concrete structure.
  • 2. The method of claim 1, further comprising the step of tilting said concrete structure to be disposed substantially upright.
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