The subject application generally relates to forms for concrete walls and in particular, to a concrete form panel and a concrete formwork comprising the same.
In the field of building and construction, formwork for constructing concrete walls consists of two spaced arrays of panels, typically fabricated of plywood, that are connected by rods, trusswork or other connecting structure. More recently, it has become desirable to use insulating material such as expanded polystyrene (EPS) for the formwork, in order to provide thermal and acoustic insulation to the finished concrete wall.
Concrete formworks comprising insulating material have been previously described. For example, U.S. Pat. No. 4,426,061 to Taggart describes a method and apparatus for forming insulated walls by pouring concrete directly on a form made in part of insulating material which will remain in place after the concrete sets. An apparatus for spacing the sheets of insulating material from the sheets of other material to create a concrete form is also described. The apparatus provides the function of bridging adjacent sheets of insulating material to create an adequate seal for the concrete.
In some applications, once the concrete has been poured and has set, it is desirable to remove or “strip” the formwork to expose the finished concrete surface. In some cases, portions of the formwork can adhere to the finished concrete surface, creating imperfections on the concrete surface.
Improvements are generally desired. It is therefore at least an object to provide a novel concrete form panel, and a concrete formwork comprising the same.
It should be appreciated that this summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to be used to limit the scope of the claimed subject matter.
Accordingly, in one aspect, there is provided a concrete form panel for a concrete formwork, the concrete form panel comprising: a foam body having a concrete-facing surface and an outward-facing surface opposite the concrete-facing surface, the outward-facing surface having a plurality of slots formed therein; and a plurality of structural elements, each structural element being accommodated in a respective slot, each structural element having apertures formed therein for accommodating ties.
Each slot may extend: at least a portion of the height of the foam body, or at least a portion of the length of the foam body. Each slot may extend the height or the length of the foam body.
Each structural element may be bonded by adhesive to the foam body. Each structural element may embedded in the foam body, the structural element being accessible from the outward-facing surface. Each structural element may engage the foam body by interference fit.
Each structural element may be sized to have an outward-facing surface that is flush with the outward-facing surface of the foam body.
Each structural element may be sized such that it protrudes beyond the outward-facing surface of the foam body. Each structural element may have an outward-facing surface that is offset from the outward-facing surface of the foam body. Each structural element may have a plurality of additional apertures formed in sidewalls thereof, the additional apertures defining a plurality of ventilation passages through the structural element. Each structural element may have an additional aperture formed in each sidewall thereof, the additional apertures defining a single ventilation passage through the structural element.
Each structural element may comprise at least one layer of corrugated material. Each layer of corrugated material may comprise a sinusoidal or zig-zag configuration of sheet material disposed between two generally planar sheets of sheet material. Corrugations of the at least one layer of corrugated material may define a plurality of ventilation passages through the structural element.
The concrete form panel may further comprise a film disposed on the concrete-facing surface. An interfacial strength between the film and the foam body may be greater than the adhesive strength between the film and set concrete. The film may be a film of plastic. The concrete form panel may further comprise an adhesive layer disposed between the film and the foam body.
The foam body may have a first lateral surface and a second lateral surface, the first and second lateral surfaces either having connecting features formed therein or the first and second lateral surfaces being generally planar. The foam body may have a top surface and a bottom surface, the top and bottom surfaces either having connecting features formed therein or the top and bottom surfaces being generally planar.
The concrete form panel may further comprise additional slots formed at edges of the outward-facing surface, each additional slot being sized to accommodate a portion of one of the structural elements.
In another aspect, there is provided a concrete formwork, comprising: a plurality of panels defining spaced, opposing sides of the formwork, at least some of the panels being concrete form panels each comprising: a foam body having a concrete-facing surface and an outward-facing surface opposite the concrete-facing surface, the outward-facing surface having a plurality of slots formed therein, and a plurality of structural elements, each structural element being accommodated in a respective slot, and each structural element having apertures formed therein for accommodating ties; and a plurality of ties accommodated by the structural elements and connecting the panels of the opposing sides of the formwork.
The panels defining both sides of the formwork may be the concrete form panels.
The panels defining a first side of the formwork may be the concrete form panels, and the panels defining a second side of the formwork are hardboard sheets. The hardboard sheets may be selected from the group consisting of: OSB (oriented strand board), plywood, fiber cement board, and cement board.
The ties may be fastened to the structural elements by fasteners, each fastener selected from the group consisting of: a threaded nut; a threaded hemispherical fastener; a clip; and a pin.
In another aspect, there is provided a method of forming a concrete wall, comprising: stacking a plurality of panels to define spaced, opposing sides of a formwork, at least some of the panels being concrete form panels each comprising: a foam body having a concrete-facing surface and an outward-facing surface opposite the concrete-facing surface, the outward-facing surface having a plurality of slots formed therein, and a plurality of structural elements, each structural element being accommodated in a respective slot, and each structural element having apertures formed therein for accommodating ties; connecting opposing panels with a plurality of ties accommodated in the structural elements; and pouring concrete into the volume defined between the opposing sides of the formwork.
The method may further comprise fastening wall finishing materials to outward-facing surfaces of the structural elements.
The connecting may further comprise: fastening the ties to the structural elements using fasteners, each fastener being selected from the group consisting of: a threaded nut; a threaded hemispherical fastener; a clip; and a pin.
Embodiments will now be described more fully with reference to the accompanying drawings in which:
The foregoing summary, as well as the following detailed description of certain examples will be better understood when read in conjunction with the appended drawings. As used herein, an element or feature introduced in the singular and preceded by the word “a” or “an” should be understood as not necessarily excluding the plural of the elements or features. Further, references to “one example” or “one embodiment” are not intended to be interpreted as excluding the existence of additional examples or embodiments that also incorporate the described elements or features. Moreover, unless explicitly stated to the contrary, examples or embodiments “comprising” or “having” or “including” an element or feature or a plurality of elements or features having a particular property may include additional elements or features not having that property. Also, it will be appreciated that the terms “comprises”, “has”, “includes” means “including by not limited to” and the terms “comprising”, “having” and “including” have equivalent meanings.
As used herein, the term “and/or” can include any and all combinations of one or more of the associated listed elements or features.
It will be understood that when an element or feature is referred to as being “on”, “attached” to, “connected” to, “coupled” with, “contacting”, etc. another element or feature, that element or feature can be directly on, attached to, connected to, coupled with or contacting the other element or feature or intervening elements may also be present. In contrast, when an element or feature is referred to as being, for example, “directly on”, “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element of feature, there are no intervening elements or features present.
It will be understood that spatially relative terms, such as “under”, “below”, “lower”, “over”, “above”, “upper”, “front”, “back” and the like, may be used herein for ease of description to describe the relationship of an element or feature to another element or feature as illustrated in the figures. The spatially relative terms can however, encompass different orientations in use or operation in addition to the orientation depicted in the figures.
Turning now to
The concrete formwork 20 comprises a plurality of concrete form panels 22 that are stacked to form two (2) spaced sides of the concrete formwork, and a plurality of ties 24 connecting opposing concrete form panels 22. When connected by the ties 24, the concrete form panels 22 define a volume 28 into which concrete is to be poured. In the example shown, the concrete form panels 22 are stacked in a staggered arrangement.
The concrete form panel 22 may be better seen in
In this embodiment, the foam body 30 has a plurality of connecting features formed therein for enabling abutting concrete form panels 22 to be connected. In the example shown, the connecting features comprise a groove 54 formed in the first lateral surface 38, a tongue 56 formed on the second lateral surface 42, a tongue 58 formed on the top surface 44, and a groove 62 formed in the bottom surface 46. In the example shown, the foam body 30 has a length of eight (8) feet, a height of four (4) feet and a thickness of six (6) inches, and the slots 48 have a pitch of twelve (12) inches, however it will be understood that the foam body 30 may alternatively be differently dimensioned.
The concrete form panel 22 also comprises a film 70 disposed on the concrete-facing surface 34 of the foam body 30. The film 70 is a film of plastic, such as polypropylene or polyester, and the like. In this embodiment, the film 70 is disposed on the concrete-facing surface 34 during molding of the foam body 30, whereby the film 70 is positioned in the mold, and becomes affixed to the foam body 30 by fusing induced by heating during molding. During use, concrete poured into the volume 28 comes into contact with the film 70 and sets within the concrete formwork 20. The film 70 and the foam body 30 are configured such that the interfacial strength between the film 70 and the foam body 30 is greater than the adhesive strength between the film 70 and the set concrete.
In the example shown, each tie 24 is in the form of a steel rod having threaded ends 74 for each engaging a fastener 76. The fastener 76 may be better seen in in
In use, the concrete formwork 20 is assembled by stacking concrete form panels 22, by engaging tongues 56 and grooves 54 of horizontally-abutting concrete form panels 22, and by engaging tongues 58 and grooves 62 of vertically-abutting concrete form panels 22, so as to form the two (2) spaced, opposing sides of the concrete formwork 20. When arranged in this manner the films 70 of the concrete form panels 22 on opposite sides of the concrete formwork 20 face each other. During stacking of the concrete form panels 22, ties 24 are inserted through opposing concrete form panels 22, such that they pass through apertures 72 of the structural elements 50, and through the foam bodies 30 and the films 70, and such that the ties 24 extend between the opposing concrete form panels 22. Fasteners 76 are then fastened to the threaded ends 74 of the ties 24 to connect the concrete form panels 22, thereby completing assembly of the concrete formwork 20 and defining the volume 28 into which the concrete is to be poured, as shown in
With the concrete formwork 20 assembled, concrete C is poured into the volume 28 defined between the concrete form panels 22 and is allowed to set, as shown in
Once the concrete has set, the fasteners 76 may be removed and the concrete form panels 22 separated from the set concrete C. As the interfacial strength between the film 70 and the foam body 30 is greater than the adhesive strength between the film 70 and the set concrete, the concrete form panel 22 easily separates from the set concrete C, with the film 70 remaining affixed to the foam body 30, resulting in a smooth surface on each side of the set concrete C. Portions of the ties 24 that project from the sides of the set concrete are then cut or cleaved using a suitable tool (not shown) such as a saw or a hammer, resulting in a concrete wall 90 having sides that are generally smooth, as shown in
Alternatively, once the concrete has set, some or all of the concrete form panels 22 may alternatively not be separated from the set concrete C, and may instead remain in place as desired to provide a layer of insulation on one or both sides of the set concrete C.
As will be appreciated, the film 70 strengthens the foam body 30, and thereby advantageously reinforces the concrete form panel 22.
As will also be appreciated, the film 70 prevents the concrete from adhering to the foam body 30, which advantageously prevents portions of the foam body 30 from breaking off during separation of the concrete from panels 22 and remaining attached to the set concrete C, otherwise creating rough surfaces on the sides of the concrete wall 90.
As will be appreciated, the structural elements 50 provide structural support to the foam body 30 and thereby strengthen the concrete form panel 22, which advantageously reduces the number of ties 24 needed to achieve the necessary structural integrity in the concrete formwork 20, as compared to conventional concrete form panels used in conventional concrete formworks.
Other configurations are possible, and in other embodiments the concrete formwork may alternatively be differently configured. For example,
In this embodiment, concrete formwork 120 comprises a plurality of the concrete form panels 22, which are described above and with reference to
Each hardboard sheet 126 is a sheet of material selected from the group consisting of OSB (oriented strand board), plywood, fiber cement board, cement board, and the like. The hardboard sheet 126 may alternatively be a sheet of one or more other suitable materials. The hardboard sheets have apertures 132 formed therein that are sized to accommodate the ties 24, and the apertures may be formed at the site of assembly of the concrete formwork 120 or may be formed prior to delivery to the site.
In use, the concrete formwork 120 is assembled by stacking concrete form panels 22, in the manner described above for concrete formwork 20, to form the first side of the concrete formwork 120. Hardboard sheets 126 are arranged to form the second side of the concrete formwork 120. When arranged in this manner, the films 70 of the concrete form panels 22 face the opposing hardboard sheets 126. As the concrete form panels 22 are being stacked and the hardboard sheets 126 are being arranged, ties 24 are inserted through the concrete form panels 22 and the hardboard sheets 126 such that they pass through apertures 72 of the structural elements 50, through the foam bodies 30 and the films 70, and through the apertures 132 of the opposing hardboard sheets 126. Fasteners 76 are then fastened to the threaded ends 74 of the ties 24 to connect the concrete form panels 22 to the hardboard sheets 126, thereby completing assembly of the concrete formwork 120 and defining the volume 128 into which the concrete is to be poured, shown in
With the concrete formwork 120 assembled, concrete is then poured into the volume 128 defined between the stacked assembly of concrete form panels 22 and the hardboard sheets 126, and is allowed to set.
Once the concrete has set, the fasteners 76 adjacent the hardboard sheets 126 are removed and the hardboard sheets 126 are separated from the set concrete. Portions of the ties 24 that project from the one (1) side of the set concrete are then cut or cleaved using a suitable tool (not shown) such as a saw or a hammer, resulting in a concrete wall having a first side that is generally smooth. The concrete form panels 22 and fasteners remain in place to provide a layer of insulation on the first side of the set concrete.
The concrete form panel is not limited to the configuration described above, and in other embodiments the concrete form panel may be differently configured. For example,
Although in the embodiment described above, the foam body 230 has a plurality of slots 248 that are oriented along the height of the foam body 230, in other embodiments, the slots may alternatively be oriented along the length of the foam body, and such that they that do not extend the full length of the foam body but rather extend a majority of the length of the foam body 230.
Unlike concrete form panel 22, concrete form panel 322 does not have a film disposed on the concrete-facing surface 34. Rather, during use, the concrete-facing surface 34 of the foam body strongly adheres to the concrete as the concrete sets in the concrete formwork. Whether the concrete form panel 322 defines the interior surface or the exterior surface of the concrete wall will depend on the positioning of the concrete form panel 322 in the concrete formwork 20 or 120.
As will be understood, the outwardly-facing surface 382 structural element 350 provides a fastening surface for exterior or interior wall finishing materials (not shown), such as drywall sheets or siding panels, for example. Additionally, the structural element 350 has a depth, defined by each sidewall 384, that is greater than the depth of the slot 48 formed in the foam body 30.
Owing to the thickness of the structural element 350, when the structural element 350 is accommodated in the slot 48, a portion of the structural element 350 protrudes by a distance D beyond the outward-facing surface 36, as indicated in
As will be appreciated, the use of structural elements 350, which provide fastening surfaces for wall finishing materials, advantageously reduces the amount of labor and cost required to finish the interior and/or exterior of the concrete wall 90, as compared to conventional concrete form panels used in prior art concrete formworks.
In other embodiments, the structural elements may be differently configured. For example,
Additionally, the structural element 1150 has a plurality of apertures 1188 formed in the sidewalls 1186, in the portion of the structural element 1150 that protrudes beyond the outward-facing surface 36. As will be understood, the apertures 1188 advantageously allow for ventilation in a generally lateral direction between the concrete form panel 22 and the finishing material. In the example shown, the positions of the apertures 1188 on opposite sidewalls 1186 are staggered, such that the apertures 1188 define diagonal flow passages through the interior of the structural element 1150, relative to the length of the structural element 1150. However, it will be understood that the positions of the apertures 1188 on opposite sidewalls 1186 may alternatively be aligned, such that such that the apertures 1188 define perpendicular flow passages through the interior of the structural element 1150, relative to the length of the structural element 1150.
Additionally, the structural element 1250 has a plurality of apertures 1288 formed in the sidewalls 1286, and in the portion of the structural element 1250 that protrudes beyond the outward-facing surface 36. As will be understood, the apertures 1288 advantageously allow for ventilation in a generally lateral direction between the concrete form panel 22 and the finishing material. In the example shown, the positions of the apertures 1288 on opposite sidewalls 1286 are staggered, such that the apertures 1288 define diagonal flow passages through the interior of the structural element 1250, relative to the length of the structural element 1250. However, it will be understood that the positions of the apertures 1288 on opposite sidewalls 1286 may alternatively be aligned, such that such that the apertures 1288 define perpendicular flow passages through the interior of the structural element 1250, relative to the length of the structural element 1250.
As will be understood, the corrugated structure of the structural element 1350 advantageously enables ventilation in a generally lateral direction between the concrete form panel 22 and the finishing material. In the example shown, the corrugations in each layer 1386 define a plurality of flow passages 1392 that traverse the width of the structural element 1350, and that are oriented generally perpendicularly to the length of the structural element 1350. However, it will be understood that the corrugations in each layer 1386 may alternatively be oriented diagonally relative to the length of the structural element 1350. The structural element 1350 may for example be a furring strip fabricated by Quarrix Building Products, a subsidiary of Liberty Diversified International of Minneapolis, U.S.A., and as described in U.S. Pat. Nos. 6,938,383 and 7,117,649.
In this embodiment, the foam body 1430 has a plurality of slots 1448 and 1452 formed in the outward-facing surface 1436, with each slot 1448 being sized to accommodate a structural element 1450, and with each slot 1452 being formed at the edge of the outward-facing surface 1436 and having half (½) the width of a slot 1448. In the example shown, the slots 1448 have a pitch of two (2) feet, however it will be understood that the foam body 1430 may alternatively be differently dimensioned.
Each structural element 1450 has a generally C-shaped cross section, and has apertures 1472 formed therein for accommodating ties 24. The structural element 1450 is fabricated of a material having suitable strength, such as steel or another metal, or plastic. The structural elements 1450 are bonded to the slots 1448 and 1452 formed in the foam body 30 by adhesive (not shown). In the example shown, the structural element 1450 has a length of four (4) feet, a width of four (4) inches and a depth of one (1) inch, however it will be understood that the structural element 1450 may alternatively be differently dimensioned.
As will be understood, when two (2) concrete form panels 1422 abut horizontally, the adjoining slots 1452 combine to provide a slot that is sized to accommodate one (1) structural element 1450. As will be understood, when ties 24 are passed through apertures 72 of a structural element 1450 accommodated by two adjoining slots 1452, the abutting concrete form panels 1422 advantageously become fastened together by the structural element 1450 and the ties 24.
The concrete form panel 1422 also comprises the film 1470, which is disposed on the concrete-facing surface 1434 of the foam body 1430. In this embodiment, the film 70 is disposed on the concrete-facing surface 34 during molding of the foam body 1430, whereby the film 70 is positioned in the mold and becomes affixed to the foam body 1430 during molding. During use, concrete poured into the volume 28 comes into contact with the film 70 and sets within the concrete formwork 20. The film 70 and the foam body 1430 are configured such that the interfacial strength between the film 70 and the foam body 1430 is greater than the adhesive strength between the film 70 and the set concrete.
In other embodiments, the fasteners may be differently configured. For example, although in the embodiment described above, the fastener is a threaded nut, in other embodiments, other fasteners may be used.
Although in the embodiments described above, the foam body of the concrete form panel is fabricated of EPS foam, in other embodiments, the concrete form panel may alternatively be fabricated of another suitable foam material, such as for example extruded polystyrene (XPS) foam.
Although in the embodiments described above, the foam body of the concrete form panel is formed by molding, in other embodiments, the foam body may alternatively be formed by cutting the foam body from a larger block of already-molded foam, such as EPS foam, XPS foam, and the like.
Although in the embodiments described above, the film 70 is disposed on the concrete-facing surface during molding of the foam body, whereby the film 70 is positioned in the mold and becomes affixed to the foam body during molding, in other embodiments, the film 70 may alternatively be disposed on the foam body after molding. For example, the film may alternatively be affixed to the concrete-facing surface by an adhesive layer, such as a glue layer, disposed between the film 70 and the concrete-facing surface of the foam body. In one such embodiment, the film 70 and glue layer may alternatively be provided on a disposable backing layer, and peeled from the backing layer and applied to the concrete-facing surface of the foam body. In other embodiments, the film may alternatively comprise two (2) or more layers of different plastic, with a first layer being polypropylene, polyester and the like, and a second layer being a plastic having a low glass transition temperature (Tg) (sometimes referred to as a “melting point”), such as polyethylene. In this embodiment, the film is affixed to the foam body by heating the film using a suitable tool, such as a hot air gun, a heater, an iron, a hot plate, and the like, so as soften or “melt” the low Tg layer. The softened or “melted” low Tg layer forms an adhesive layer, and thereby cause the first layer to adhere and become affixed to the foam body.
Although in the embodiments described above, the foam body has connecting features formed therein for enabling abutting concrete form panels to be connected, with the connecting features comprising a groove formed in the first lateral surface, a tongue formed on the second lateral surface, a tongue formed on the top surface, and a groove formed in the bottom surface, it will be understood that the connecting features are merely exemplary in shape and number, and other shapes and numbers of connecting features may alternatively be used. In other embodiments, the lateral surfaces, and/or the top and bottom surfaces, may alternatively have no connecting features formed thereon or therein, and may alternatively be generally planar surfaces.
Although in the embodiments described above, the foam body has a plurality of slots formed therein and the structural elements are bonded to the slots by adhesive, in other embodiments, the structural elements may alternatively not be bonded by adhesive and may instead be applied to and held against the foam body using the ties and fasteners. In other embodiments, the structural elements may alternatively be held in the slots by interference fit. For example, in one such embodiment, the slots may alternatively be sized smaller than the structural elements, so as to retain the structural elements by interference fit. In other embodiments, the foam body may have inwardly-extending grooves or other features formed therein adjacent the slots, and the structural elements may further comprise outwardly-extending tabs for engaging the grooves by interference fit. In still other embodiments, the foam body may alternatively be molded with the structural elements embedded therein, with the embedded structural elements being accessible from the concrete-facing surface of the foam body.
Although in embodiments described above, the concrete form panel comprises a film 70 disposed on the concrete-facing surface of the foam body, in other embodiments, the concrete form panel may alternatively also comprise a film 70 disposed on the outward-facing surface of the foam body, opposite the concrete-facing surface.
Although in the embodiments described above, each tie 24 is in the form of a steel rod having threaded ends for each engaging a fastener in the form of a threaded nut, in other embodiments, the tie and fastener may alternatively be differently configured. For example, in one embodiment, each tie may alternatively comprise two (2) or more connectable components which when connected provide a tie. As another example, in another embodiment, the tie and fasteners may alternatively be a single bolt and one fastener. Those skilled in the art will understand that still other configurations are possible. The tie may alternatively by fabricated of a suitable material other than steel, such as another metal or plastic.
Although in embodiments described above, the structural element has a plurality of apertures formed in the sidewalls, in the portion of the structural element that protrudes beyond the outward-facing surface, for allowing ventilation in a generally lateral direction between the concrete form panel and the finishing material, in other embodiments, the structural element may alternatively have only a single aperture, or a single elongate or slot-shaped opening, formed in each sidewall in the portion of the structural element that protrudes beyond the outward-facing surface, both of which thereby define only a single flow passage through the structural element.
Although embodiments have been described above with reference to the accompanying drawings, those of skill in the art will appreciate that variations and modifications may be made without departing from the scope thereof as defined by the appended claims.