Ultrathin, pre-stressed, concrete component system

Abstract

The UTPSCCS is a three-part, pre-fabricated structure that consists of a concrete panel mounted between two concrete columns. Multiple components are assembled to form the exterior wall of a Passive House. A Passive House is a highly-insulated building that achieves at least 80% energy efficiency via airtight construction and a minimal transfer of heat between exterior walls and an interior living space. The UTPSCCS is suitable for Passive House construction because the wall is a free-standing shell that does not touch the interior living space and, thus, does not transfer heat. The UTPSCCS panel may alternatively be used as a wall to provide noise suppression along highways, between traffic and residential properties, or as a wall to separate areas within a property or a wall to separate many properties from the general public.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the construction and manufacture of an ultrathin, prestressed, concrete component system for construction of an exterior wall for a Passive House building, or other types of wall for noise barrier or separation of areas within a property, or separation of properties from the general public.BACKGROUND OF THE INVENTION

[0002] Typical exteriors of buildings consist of a variety of materials, including masonry, concrete, metal, and glass. Reinforced concrete and steel frame or wood frame structures often have cladding systems to protect them from vibrations and climatic conditions. The patent document U.S. Pat. No. 6,711,866 B2 (inventor Brian M. Blount, May 30, 2004) discloses a thin prestressed concrete cladding panel with six steel wire tendons. The panel is described as approximately 1.5 inches thick, and the design includes a bolt-and-screw system embedded within the panel. A wall composed of 1.5-inch-thick panels, each with six steel tendons, requires a large amount of materials. It is not only heavy and expensive but depletes environmental resources. The bolts and screws connect the concrete cladding with the building's interior space and create thermal bridging, which negatively impacts energy efficiency of a building. Construction material costs are high due to the extra thickness of the Blount panel (i.e, 1.5 inches versus 0.5 inch for the panel described herein), as well as the provision of bolts and screws to keep the panel in place in the built environment; installation of the Blount panel (labor costs) is expensive because of the cost to install the many bolts that must be used to secure said panels to a building structure. Maintenance costs for the Blount panel are high (labor costs) because of the freeze-thaw cycle (i.e., loosening of the bolts and screws and the re-tightening of them) at the bolts and screws and other connections between the Blount panel and building exterior.SUMMARY

[0003] The invention remedies the aforementioned drawbacks by providing a panel that is ultrathin (0.5 inch) and a component system that is freestanding, without screws, bolts, or brackets. Ultrathin, pre-stressed, concrete component system (UTPSCCS), comprising three-part, prefabricated components, consists of a concrete panel mounted between two concrete columns. Multiple components are assembled to form the exterior wall of a Passive House or other structure as described below. A Passive House is a highly insulated building that achieves at least 80% energy efficiency via airtight construction and a minimal transfer of heat between exterior walls and an interior living space. The UTPSCCS is suitable for Passive House construction because the wall is a free-standing shell that does not touch the interior living space, does not transfer heat, and achieves zero thermal bridging. Special care is taken at the windows (not shown) and doors (not shown) (and other penetrations, not shown) to minimize the de minimis thermal bridging effects there. Triple pane windows can reduce thermal bridging through the glazing, and insulation and airtight construction can reduce thermal bridging at the perimeter of the door and window frames. Part one of the UTPSCCS is a concrete panel that is flat on the face and has a raised grid on the reverse side. The grid pattern provides additional flexural strength without having the panel be thicker everywhere, thereby requiring less concrete material and less weight. Prestressed stainless steel cable is embedded within the concrete panel along each line of the grid. There are two types of panels. Type 1 designates the panel that is placed along the base of the assembled wall, subsequently referred to as the “bottom-most panel.” Type 2 designates the panels that are stacked on top of the Type 1 panels, subsequently referred to as the “stackable panel.” Both types are flat on their faces. Both are 0.5 inches thick with raised grids that protrude from their reverse sides. Both contain 1 / 16-inch diameter cables embedded within their panels and / or grid elements. The difference between Type 1 and Type 2 panels is the grid pattern. The grid on the bottom-most panel protrudes a consistent 0.5 inch from its reverse surface. On the stackable panel, the majority of the grid pattern protrudes 0.5 inch but there is a wider, thicker horizontal grid bar nearest the base of the panel, which protrudes 1.5 inches. The purpose of the wider, thicker bar in the stackable panel is to provide a ridge for resting on the panel below it. The grid spacings and the thickness of the grid and panels remain consistent no matter the size of the panels. Parts 2 and 3 of the UTPSCCS are mirror-image concrete columns that assist in holding each panel in place. The panels are inserted into cavities in the columns. There are two types of column: Type 1, linear columns that allow panels to be placed along the length of a building; and Type 2, corner columns that are placed at the corners of the building. The linear column has slots (set at 180 degrees from each side) into which panels are stacked vertically. The corner column is configured with slots to hold two sets of stacked panels set at a 90-degree angle to one another. There are no nails, screws, or brackets required to keep the panels in place; panel wall integrity is accomplished by gravity effects. The panels and columns can be sized and cast in the desired dimensions. The spacing of the ½-inch grids is variable, based on the desired flexural panel strength. The panels and columns are then assembled horizontally and vertically and at angles to form walls. The height of the columns and the distance between them may vary depending on the dimensions of the wall and the size of the panels. But the other dimensions of the columns remain the same.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The nineteen (19) figures (FIGS.) described below comprise a set to adequately explain the components of the UTPSCCS and how they are assembled to create an exterior wall system for a Passive House, or other type of structure as described below.

[0005] FIG. 1—Part 1, Type 1 (bottom-most) panel, face view.

[0006] FIG. 2—Part 1, Type 1 (bottom-most) panel, illustrating the raised grid pattern, reverse view.

[0007] FIG. 3—Part 1, Type 1 (bottom-most) panel, illustrating the placement of the embedded cable along the grid lines, reverse view.

[0008] FIG. 4—Part 1, Type 1 (bottom-most) panel, illustrating the location of the pre-stressed cable and raised grid line, edge view

[0009] FIG. 5—Part 1, Type 2 (stackable) panel, face view.

[0010] FIG. 6—Part 1, Type 2 (stackable) panel, illustrating the raised grid pattern and the singular stackable grid line, reverse view.

[0011] FIG. 7—Part 1, Type 2 (stackable) panel, illustrating the placement of the embedded cable along the grid lines and the singular stackable grid line, reverse view

[0012] FIG. 8—Part 1, Type 2 (stackable) panel, illustrating the locations of the pre-stressed cables, raised grid, and singular stackable grid, edge view

[0013] FIG. 9—Part 2 or Part 3 corner columns, four views

[0014] FIG. 10—Part 2 or Part 3 corner column, top view dimensions

[0015] FIG. 11—Part 2 or Part 3 linear column, four views

[0016] FIG. 12—Part 2 or Part 3 linear column, top view dimensions

[0017] FIG. 13—Part 2 or Part 3, one side of a corner or linear column, edge view dimensions

[0018] FIG. 14—Part 2 or Part 3, column edge view, illustrating the UTPSCCS bottom-most and stackable panels

[0019] FIG. 15—Part 2 or Part 3, column edge view, illustrating the UTPSCCS stacked panels within the column

[0020] FIG. 16—Part 1, Part 2, and Part 3 assembled UTPSCCS partial wall assembly, face view

[0021] FIG. 17—Part 1, Part 2, and Part 3 assembled UTPSCCS completed wall assembly, four sides top view.

[0022] FIG. 18—Photo of Two Prototype Part 1 panels (stacked), and Part 2 and Part 3 columns, reverse and oblique views

[0023] FIG. 19—Tensioning device for a continuous cable before concrete is poured into a panel rubber mold; oblique view.DETAILED DESCRIPTION

[0024] The UTPSCCS has three unique features: a) Concrete panels that are thinner than commercially-available prestressed panels due to the raised grid pattern; b) a panel-in-slot (cavity) design that requires no bolts, no screws, nor any other fastener; and c) a free-standing shell that has no contact with an interior space (except at the minimal points where windows, doors, and utility penetrations are identified), thus drastically limiting heat transfer, i.e., thermal bridging. A detailed description of each figure is provided below. This section concludes with: a) Description of the rubber mold device not shown; b) alternate uses for the UTPSCCS panel; and c) the recipe for the concrete in the UTPSCCS panel (Part 1 of the patent). The recipe for the concrete in the linear and corner columns (Parts 2 and 3 of the patent) is not provided, as the appropriate recipe is not proprietary.

[0025] Referring first to FIGS. 1-8, there is therein illustrated a preferred embodiment of the invention comprising an ultrathin, prestressed reinforced concrete panel 10 and 11, which maybe, for example 144 inches in length, 72 inches in width, and have a ½ inch thickness. This size is only illustrative as the panel may be made of a variety of sizes. An ultrathin panel as used herein refers to a panel with a maximum thickness of approximately ½ inch. The illustrated panels 10 and 11 are formed with an exposed face 12 for all panel types, and an opposite back face 14 (for the Part 1, Type 1, bottom-most panel), and 16 (for the Part 1, Type 2, stackable panel) each of which faces are flat and parallel to one another. Alternatively, the exposed face 12 may be textured rather than flat to achieve a desired architectural appearance on the panel. Panel 10 is shown as formed with a pair of opposite side faces, or edges, 60, 62, and a pair of opposite side faces, or edges, 70, 72. In the illustrated embodiment the side and faces are at 90-degree angles with each other and are mirror images of each other in shape. Extending through the panel 10 and 11 is a prestressed, parallel tendon, which may comprise a singular, longitudinally extending stainless steel wire rope 30. This single wire rope extends between the side faces 60, 62 and side faces 70, 72 (for panel 10), and side faces 64, 66 and side faces 74, 76 (for panel 11).

[0026] Referring more particularly to FIG. 4, the tendon 30, spaced a distance d1 (as measured in a center line with respect to the panel grid feature (on panel face 14), from the exposed face 12. The distance d1 is preferably approximately equal to ⅜ inches and distances d2 is preferably approximately equal to 0.4 inches from either edge of the 112, 114 grid features on face 14, in the case of the ½ inch panel, T1. The tendon diameter is preferably 1 / 16-inch, 7×7 strand stainless steel wire rope. Such rope configuration facilitates formation of a secure bond between the concrete and the rope 30, and positioning it ⅜ inch from the panel face 12 assures that the tensioning effect will be present not only in the ½ inch portion of the panel 10 between panel edges 60, 62, but also in the raised grid elements 112, 114 of panel 10, and also along the raised grid elements 112 and 114 of panel 11 in FIG. 8. FIG. 7 and FIG. 8 also illustrate the tendon 30 near the raised grid element 114 of panel 11, and where a set of three tendons 30 extend along the grid element 116 between the 74, 76 edges. The three tendons of grid element 116 are equally spaced at a d3 distance from the face 16 of panel 11, preferably ¾ inch, and each one separated by d4, preferably 11 inch, and from each edge of the grid element 116. Note that in panels 10 and 11, the grid elements 112, 114 are raised T2, preferably 0.5 inch, and T3 across, preferably ¾ inch, while in panel 11, grid element 116 is raised T4, preferably 1.5 inches, and T5 across, preferably 5 inches, with T6 distance from the bottom of grid element 116 to the panel 11 edge 66, preferably 4 inches.

[0027] Referring, second, to FIGS. 9-12, there is therein illustrated a preferred embodiment of another feature of the invention comprising a corner column 80 and a linear column 50. FIG. 9 illustrates column 80, where top face 25A, bottom-up face 20, face 24, face 23, face 22, and face 21 are illustrated. FIG. 10 also illustrates column 80, but only the top face 25A, with preferred dimensions, including the overall dimensions of T7 by T8, preferably approximately 29 inches by 13 inches, with a cavity depth (for panel 10 and 11 insertion) of T9, preferably 12½ inch and a cavity width of T10, preferably 4 inches. The housing for the panel slot is T11, preferably 4½ inches thick, with a slot channel base of T12, preferably 3½ inches. FIG. 11 illustrates column 50, where top face 25B, bottom-up face 90, face 29, face 28, face 27, and face 26 are illustrated. FIG. 12 illustrates column 50, but only the top face 25B, with preferred dimensions, including the overall dimensions of T13 by T14, preferably approximately 32 inches by 13 inches, with a cavity depth (for panel 10 and 11 insertion) of T15, preferably 12½ inch and a cavity width of T16, preferably 4 inches. The housing for the panel slot is T17, preferably 4½ inches thick, with a slot channel base of T18, preferably 3½ inches.

[0028] Referring, second, to FIGS. 13 to 15, there is therein illustrated a preferred embodiment of another feature of the invention comprising column 50 and column faces 26, 28. FIG. 13 illustrates column 80, but only the column face 26, with locations of column face 25B, column face 29, column face 90, and column face 27. The column slot cavity has various dimensions T19 (with a dimension dependent on the desired height of a constructed wall), T20 (with a preferred dimension of 13 inches), T21 (with a preferred dimension of 5½ inches), T22 (with a preferred dimension of 4½ inches), T23 (with a preferred dimension of 4½ inches), T24 (with a preferred dimension of 4 inches), T25 (with a preferred dimension of 5½ inches), T26 (with a preferred dimension of 3 inches), T27 (with a preferred dimension of 5½ inches), T28 (with a preferred dimension of 2 inches), and T29 (with a preferred dimension of 6½ inches). FIG. 14 also illustrates column 50, column face 26, with locations of column faces 27, 29, 90, 25B. To the right of column 50 is a panel 10 with panel edge 70 and the location of panel edges 60, 62 and panel faces 12, 14. Above panel 10 are two panels 11. Each one has panel edge 74, and locations of panel edges 64, 66 and panel faces 12, 16. FIG. 15 illustrates two columns 50, each with three panels stacked within the column cavity. The column 50 to the left illustrates column face 28, and the locations of column faces 27, 29, 90, 25B. Of the stacked panels, the bottom-most is a panel 10, with a panel 11 resting upon a panel 10 with a grid element 116 (FIG. 8) of panel 11 sitting directly on panel 10's panel edge 60. Upon the panel 11 just mentioned is another panel 11, stacked in an identical way as discussed above, except, now, the second panel 11's grid element 116 rests upon the lower panel 11 panel edge 64. Additional panels 11 maybe stacked to achieve a desired height of a well with, likewise, extending the height of the columns 50, 80 to accommodate the extra panel height. Alternatively, the desired wall height may comprise a single panel 10 and appropriately-sized columns 50, 80.

[0029] Referring, third, to FIG. 16 to 17, there is therein illustrated a preferred embodiment of another feature of the invention comprising three columns 50 with two sets of stacked panels 10 and 11 resting between two columns 50 and one set of panels between a column 80 and a column 50. Each column 50 illustrates its panel face 29, while column 80 illustrates its column face 22. As illustrated in FIG. 15, the bottom-most panel in each stack is a panel 10 and each panel above it is a panel 11. FIG. 17 illustrates ten columns 50 and four columns 80 in a top view of a panel wall that totally surrounds an interior space. The illustrated top edges of the panels 11 are panel edges 64. The illustrated top of column 50 faces is column edge 25B and the top of columns face for columns 80 is column edges 25A. Note that the illustrated interior space could be a Passive House structure, that has no thermal bridging between its space and the columns 50, 80 or panels 10, 11.

[0030] Referring, fourth, to FIG. 18, there is therein illustrated a preferred embodiment of another feature of the invention comprising two columns 50, a panel 10 and panel 11. That figure is a photo of constructed panel 11 stacked upon panel 10, resting between tow columns 50, within each column's cavity.

[0031] Referring, fifth, to FIG. 19, there is therein illustrated a preferred embodiment of the invention, comprising the framing element 110, tensioning device 102, and cable 30 that is used to pre-tension the singular cable 30 through a panel 10 or panel 11. The preferred material of construction for framing element 110 is wood, size 2″ by 4″ and as long and wide as desired to produce the desired panel size. The exact spacing between the holes illustrated on framing element 110 faces 00, 02, 04, 06 are only important as they align to the precise holes of the rubber mold (not shown) into which the concrete mix for panel 10 and panel 11 is poured. The holes of framing element 110 faces 00, 02, 04, 06 align with the position of the wire rope 30 illustrated as described: a) Panel 10 in FIG. 3, panel edges 60, 62, 70, 72; b) panel 10 in FIG. 4, panel edge 60; c) panel 11 in FIG. 7, panel edges 64, 66, 74, 76; and d) panel 11, FIG. 8, panel edge 74 and grid element 116.Rubber Mold Feature Not illustrated

[0032] In both the Blount patent and the application herein, the mold device into which concrete is poured (see concrete recipe for panels 10, 11 below) are not illustrated. Such a device is typically composed of a rubber material, placed within the framing element 110 (for example) illustrated in FIG. 19, at the appropriate position so that the singular cable 30 becomes embedded at the depth into the panels 10, 11 identified in FIGS. 3, 4, 7, and 8 after the concrete is poured. The prestress force (about 40 pounds of tension) is not released until the concrete is fully cured, after about 48 hours.Alternative Uses for UTPSCCS Panel

[0033] The potential uses for the UTPSCCS panel are described below.

[0034] a) Exterior wall for a Passive House. In this application, the key feature is the separation of the exterior wall from the interior living spaces. Whenever materials of construction provide a pathway for heat transfer between outside climate conditions to interior climate-controlled conditions, the costs of maintaining a comfortable living space increase, due to the costs of heating, cooling, and / or humidity control. The Passive House exterior wall application for the UTPSCCS panel allows for a minimum of thermal bridging, to only those locations where there are windows and doors, and utility penetrations of the panel. See FIG. 18 for a depiction of this application.

[0035] b) Highway noise barriers, separation within a property, or the separation of multiple properties from the general public. In this application, the key feature is the linear panel and columns constructed to a desired height to control access or noise between a highway and a residential area. A benefit of the UTPSCCS panel over other similar wall designs is the relative ease of replacement, should a panel become damaged. This is so, as the panels may be raised out of their configuration and a replacement panel inserted to correct a defect as there are no fasteners. See FIG. 16 for a depiction of this application.Considerations for the Creation of the Product of the Invention

[0036] There are six considerations important to the preparation and manufacturing of items comprising this invention.

[0037] 1. For panels that are exposed to moist atmospheres, it is desirable that the cable be non-corrosive. In place of stainless steel wire rope, carbon fiber tendons or glass fiber tendons or others could be used. In any event, a tendon must have a surface suitable for forming a firm bond between the tendon and the concrete. The tendon material should also be strong enough to limit relaxation over time so as not to lose the prestress of approximately 40 pounds which has proven satisfactory.

[0038] 2. The concrete mix utilized should be one that will have durability under the climatic conditions to which the panel will be exposed such as freeze / thaw cycles, and should be resistant to shrinkage so that prestress will not be lost and the panel's architectural appearance will be maintained. To optimize the properties of the concrete, the aggregate size preferably should not exceed one half of the panel thickness (e.g., 14 inch) and the concrete mix should have a low water-cement ratio. See concrete recipe below.

[0039] 3. On account of the aggregates in the concrete mix, it is difficult to obtain a flat back face 14, 16 on panels 10, 11 respectively. So that a flat back face and flat panel grid elements 112, 114, 116 are obtained, the concrete mix (provided below) should be mixed first without the aggregates, and immediately placed within the rubber mold for panel 10 or panel 11, filling up the cavities for grid elements 112, 114, 116, creating a ⅛ inch covering for the produced panel faces 14, 16. Within 15 minutes of pouring the mix just described, the proper amount of aggregate is added to the concrete now remaining, mixed for uniformity, then poured upon what has already been poured. In this way, the surfaces of the rubber mold for panel 10, 11 are covered with the smooth cement and sand mixture before the aggregate has a chance to sink, placing the aggregate next to this cement-sand layer but not next to the rubber mold surface.

[0040] 4. Tensioning means are provided for applying tension to the wire rope during the casting and hardening of the panel. Referring more particularly in FIG. 19, the illustrated tensioning device 102 is arranged to apply tension to the single wire rope 30. The wire rope 30 is inserted into the tensioning device 102 suitably mounted to the framing element 110, then inserted into the hole on the framing element face 06 nearest the tensioning device 102, extending longitudinally to the hole on the other end of framing element 110, exiting framing element face 04, then reinserted into the framing element face 04 at the next hole of framing element 110, and repeating the above step at the other end of the framing element 110, where wire rope 30 re-enters framing element face 06, exits framing element 04, and then goes around framing element 110 to enter the nearest hole on framing element face 02, and continues this weaving action between framing element faces 02 and 00 until the wire rope 30 exits the second to the last hole nearest the tensioning device 102 on framing element 00, where wire rope 30 goes through framing element 110, exits framing element face 06 and enters the tensioning device 102 to join the other end of wire rope 30 so that the tensioning device 102 can simultaneously apply tension to both ends of wire rope 30, to about 40 pounds of tension. The steps outlined above provide the arrangement of the wire rope along the panel grid elements 112, 114, 116 positions illustrated in FIGS. 3, 4, 7, 8 as provided by a rubber mold (not shown). In this way, the exact positioning of the holes on frame element faces 00, 02, 04, 06 are not important, although the holes in the rubber mold next to the interior faces of the frame element 110 are critical to wire rope 30 positioning in the rubber mold prior to the pouring of the cement mix. The key to the weaving of wire rope 30 through the wooden frame element 110 is angling the wire rope 30 entrance and exit holes such that wire rope 30 never bends at a 90-degree angle, which may damage the wire rope 30 and cause failure when tension is applied.

[0041] 5. When the wire rope 30 is in place and the proper tension applied thereto, a concrete mix of desired composition may be poured into the mold. If desired, a texturing element may be applied upon the surface of the just-poured concrete mix. A vibrating device (not shown) may be used to flatten the wet concrete surface, before texturing if texturing is applied. In order to avoid warping of the cured concrete, framing element 110 and the poured concrete should not be moved while curing and the tension applied to wire rope 30 is not released until the concrete is fully cured. Various concrete curing techniques such as steam curing (i.e., an atmosphere of between 120-140 degrees F. for the first 18 hours of concrete curing) may be used if the ambient temperature of the concrete curing room cannot be kept consistent during the estimated 48 hour curing period. When the panel has developed sufficient strength, the tension on the wire rope 30 is released using wire cutters on the wire rope 30 at the tension device 102, then cut at the edges of the panels 10, 11 prior to removal from the rubber mold (not shown). The panels 10, 11 may be allowed to continue to cure in a moist environment for up to five days, thereby reducing the panel's resistance to shrinkage and maintain pre-stress.

[0042] 6. It is noteworthy to point out that the panel faces 14 and 16, with the gridded elements 112, 114, and 116 (waffle-like) are advantageous in that this design feature provides a higher strength to weight ratio than a flat faced panel without the grid.Recipe for UTPSCCS Panel Concrete

[0043] The concrete for the UTPSCCS panel is composed of: a) Portland Pozzolana Cement; b) sand; c) ¼-inch gravel (or similar material, such as recycled glass); d) water; and e) super plasticizer. Note that this recipe includes a melamine plasticizer, also known as polycarboxylate plasticizer, which can reduce the amount of water in the concrete mix by 15% to 20%, and increase the strength of the concrete.

[0044] The constituent ratio and weight of each material for the panel 10, 11 concrete mix are as follows: a) cement 2.4 lb or 1,104 g; b) sand 2.4 lb or 1,104 g; c) ¼-inch gravel 2.4 lb or 1,104 g; d) water 1.0 lb or 441.5 g; and e) super plasticizer 0.002 lb or 0.077 g. Without the cable 30, this mix weighs 8.2 pounds. But this 8.2 pounds of concrete mix will produce an approximate 2.5 square foot (by 0.5 inch thick) panel 10, 11, so the per square foot weight of the cured concrete is approximately 6.6 pounds.

[0045] Note: the recipe for the columns 50, 80 is not provided as it is not proprietary. Only the shape of the columns is proprietary with cavities and cavity protrusions illustrated in FIGS. 9, 10, 11, 12, 13, 14, and 15.

Examples

Embodiment Construction

[0024]The UTPSCCS has three unique features: a) Concrete panels that are thinner than commercially-available prestressed panels due to the raised grid pattern; b) a panel-in-slot (cavity) design that requires no bolts, no screws, nor any other fastener; and c) a free-standing shell that has no contact with an interior space (except at the minimal points where windows, doors, and utility penetrations are identified), thus drastically limiting heat transfer, i.e., thermal bridging. A detailed description of each figure is provided below. This section concludes with: a) Description of the rubber mold device not shown; b) alternate uses for the UTPSCCS panel; and c) the recipe for the concrete in the UTPSCCS panel (Part 1 of the patent). The recipe for the concrete in the linear and corner columns (Parts 2 and 3 of the patent) is not provided, as the appropriate recipe is not proprietary.

[0025]Referring first to FIGS. 1-8, there is therein illustrated a preferred embodiment of the inven...

FIELD OF THE INVENTION

[0001] The present invention relates to the construction and manufacture of an ultrathin, prestressed, concrete component system for construction of an exterior wall for a Passive House building, or other types of wall for noise barrier or separation of areas within a property, or separation of properties from the general public.BACKGROUND OF THE INVENTION

[0002] Typical exteriors of buildings consist of a variety of materials, including masonry, concrete, metal, and glass. Reinforced concrete and steel frame or wood frame structures often have cladding systems to protect them from vibrations and climatic conditions. The patent document U.S. Pat. No. 6,711,866 B2 (inventor Brian M. Blount, May 30, 2004) discloses a thin prestressed concrete cladding panel with six steel wire tendons. The panel is described as approximately 1.5 inches thick, and the design includes a bolt-and-screw system embedded within the panel. A wall composed of 1.5-inch-thick panels, each with six steel tendons, requires a large amount of materials. It is not only heavy and expensive but depletes environmental resources. The bolts and screws connect the concrete cladding with the building's interior space and create thermal bridging, which negatively impacts energy efficiency of a building. Construction material costs are high due to the extra thickness of the Blount panel (i.e, 1.5 inches versus 0.5 inch for the panel described herein), as well as the provision of bolts and screws to keep the panel in place in the built environment; installation of the Blount panel (labor costs) is expensive because of the cost to install the many bolts that must be used to secure said panels to a building structure. Maintenance costs for the Blount panel are high (labor costs) because of the freeze-thaw cycle (i.e., loosening of the bolts and screws and the re-tightening of them) at the bolts and screws and other connections between the Blount panel and building exterior.SUMMARY

[0003] The invention remedies the aforementioned drawbacks by providing a panel that is ultrathin (0.5 inch) and a component system that is freestanding, without screws, bolts, or brackets. Ultrathin, pre-stressed, concrete component system (UTPSCCS), comprising three-part, prefabricated components, consists of a concrete panel mounted between two concrete columns. Multiple components are assembled to form the exterior wall of a Passive House or other structure as described below. A Passive House is a highly insulated building that achieves at least 80% energy efficiency via airtight construction and a minimal transfer of heat between exterior walls and an interior living space. The UTPSCCS is suitable for Passive House construction because the wall is a free-standing shell that does not touch the interior living space, does not transfer heat, and achieves zero thermal bridging. Special care is taken at the windows (not shown) and doors (not shown) (and other penetrations, not shown) to minimize the de minimis thermal bridging effects there. Triple pane windows can reduce thermal bridging through the glazing, and insulation and airtight construction can reduce thermal bridging at the perimeter of the door and window frames. Part one of the UTPSCCS is a concrete panel that is flat on the face and has a raised grid on the reverse side. The grid pattern provides additional flexural strength without having the panel be thicker everywhere, thereby requiring less concrete material and less weight. Prestressed stainless steel cable is embedded within the concrete panel along each line of the grid. There are two types of panels. Type 1 designates the panel that is placed along the base of the assembled wall, subsequently referred to as the “bottom-most panel.” Type 2 designates the panels that are stacked on top of the Type 1 panels, subsequently referred to as the “stackable panel.” Both types are flat on their faces. Both are 0.5 inches thick with raised grids that protrude from their reverse sides. Both contain 1 / 16-inch diameter cables embedded within their panels and / or grid elements. The difference between Type 1 and Type 2 panels is the grid pattern. The grid on the bottom-most panel protrudes a consistent 0.5 inch from its reverse surface. On the stackable panel, the majority of the grid pattern protrudes 0.5 inch but there is a wider, thicker horizontal grid bar nearest the base of the panel, which protrudes 1.5 inches. The purpose of the wider, thicker bar in the stackable panel is to provide a ridge for resting on the panel below it. The grid spacings and the thickness of the grid and panels remain consistent no matter the size of the panels. Parts 2 and 3 of the UTPSCCS are mirror-image concrete columns that assist in holding each panel in place. The panels are inserted into cavities in the columns. There are two types of column: Type 1, linear columns that allow panels to be placed along the length of a building; and Type 2, corner columns that are placed at the corners of the building. The linear column has slots (set at 180 degrees from each side) into which panels are stacked vertically. The corner column is configured with slots to hold two sets of stacked panels set at a 90-degree angle to one another. There are no nails, screws, or brackets required to keep the panels in place; panel wall integrity is accomplished by gravity effects. The panels and columns can be sized and cast in the desired dimensions. The spacing of the ½-inch grids is variable, based on the desired flexural panel strength. The panels and columns are then assembled horizontally and vertically and at angles to form walls. The height of the columns and the distance between them may vary depending on the dimensions of the wall and the size of the panels. But the other dimensions of the columns remain the same.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The nineteen (19) figures (FIGS.) described below comprise a set to adequately explain the components of the UTPSCCS and how they are assembled to create an exterior wall system for a Passive House, or other type of structure as described below.

[0005] FIG. 1—Part 1, Type 1 (bottom-most) panel, face view.

[0006] FIG. 2—Part 1, Type 1 (bottom-most) panel, illustrating the raised grid pattern, reverse view.

[0007] FIG. 3—Part 1, Type 1 (bottom-most) panel, illustrating the placement of the embedded cable along the grid lines, reverse view.

[0008] FIG. 4—Part 1, Type 1 (bottom-most) panel, illustrating the location of the pre-stressed cable and raised grid line, edge view

[0009] FIG. 5—Part 1, Type 2 (stackable) panel, face view.

[0010] FIG. 6—Part 1, Type 2 (stackable) panel, illustrating the raised grid pattern and the singular stackable grid line, reverse view.

[0011] FIG. 7—Part 1, Type 2 (stackable) panel, illustrating the placement of the embedded cable along the grid lines and the singular stackable grid line, reverse view

[0012] FIG. 8—Part 1, Type 2 (stackable) panel, illustrating the locations of the pre-stressed cables, raised grid, and singular stackable grid, edge view

[0013] FIG. 9—Part 2 or Part 3 corner columns, four views

[0014] FIG. 10—Part 2 or Part 3 corner column, top view dimensions

[0015] FIG. 11—Part 2 or Part 3 linear column, four views

[0016] FIG. 12—Part 2 or Part 3 linear column, top view dimensions

[0017] FIG. 13—Part 2 or Part 3, one side of a corner or linear column, edge view dimensions

[0018] FIG. 14—Part 2 or Part 3, column edge view, illustrating the UTPSCCS bottom-most and stackable panels

[0019] FIG. 15—Part 2 or Part 3, column edge view, illustrating the UTPSCCS stacked panels within the column

[0020] FIG. 16—Part 1, Part 2, and Part 3 assembled UTPSCCS partial wall assembly, face view

[0021] FIG. 17—Part 1, Part 2, and Part 3 assembled UTPSCCS completed wall assembly, four sides top view.

[0022] FIG. 18—Photo of Two Prototype Part 1 panels (stacked), and Part 2 and Part 3 columns, reverse and oblique views

[0023] FIG. 19—Tensioning device for a continuous cable before concrete is poured into a panel rubber mold; oblique view.DETAILED DESCRIPTION

[0024] The UTPSCCS has three unique features: a) Concrete panels that are thinner than commercially-available prestressed panels due to the raised grid pattern; b) a panel-in-slot (cavity) design that requires no bolts, no screws, nor any other fastener; and c) a free-standing shell that has no contact with an interior space (except at the minimal points where windows, doors, and utility penetrations are identified), thus drastically limiting heat transfer, i.e., thermal bridging. A detailed description of each figure is provided below. This section concludes with: a) Description of the rubber mold device not shown; b) alternate uses for the UTPSCCS panel; and c) the recipe for the concrete in the UTPSCCS panel (Part 1 of the patent). The recipe for the concrete in the linear and corner columns (Parts 2 and 3 of the patent) is not provided, as the appropriate recipe is not proprietary.

[0025] Referring first to FIGS. 1-8, there is therein illustrated a preferred embodiment of the invention comprising an ultrathin, prestressed reinforced concrete panel 10 and 11, which maybe, for example 144 inches in length, 72 inches in width, and have a ½ inch thickness. This size is only illustrative as the panel may be made of a variety of sizes. An ultrathin panel as used herein refers to a panel with a maximum thickness of approximately ½ inch. The illustrated panels 10 and 11 are formed with an exposed face 12 for all panel types, and an opposite back face 14 (for the Part 1, Type 1, bottom-most panel), and 16 (for the Part 1, Type 2, stackable panel) each of which faces are flat and parallel to one another. Alternatively, the exposed face 12 may be textured rather than flat to achieve a desired architectural appearance on the panel. Panel 10 is shown as formed with a pair of opposite side faces, or edges, 60, 62, and a pair of opposite side faces, or edges, 70, 72. In the illustrated embodiment the side and faces are at 90-degree angles with each other and are mirror images of each other in shape. Extending through the panel 10 and 11 is a prestressed, parallel tendon, which may comprise a singular, longitudinally extending stainless steel wire rope 30. This single wire rope extends between the side faces 60, 62 and side faces 70, 72 (for panel 10), and side faces 64, 66 and side faces 74, 76 (for panel 11).

[0026] Referring more particularly to FIG. 4, the tendon 30, spaced a distance d1 (as measured in a center line with respect to the panel grid feature (on panel face 14), from the exposed face 12. The distance d1 is preferably approximately equal to ⅜ inches and distances d2 is preferably approximately equal to 0.4 inches from either edge of the 112, 114 grid features on face 14, in the case of the ½ inch panel, T1. The tendon diameter is preferably 1 / 16-inch, 7×7 strand stainless steel wire rope. Such rope configuration facilitates formation of a secure bond between the concrete and the rope 30, and positioning it ⅜ inch from the panel face 12 assures that the tensioning effect will be present not only in the ½ inch portion of the panel 10 between panel edges 60, 62, but also in the raised grid elements 112, 114 of panel 10, and also along the raised grid elements 112 and 114 of panel 11 in FIG. 8. FIG. 7 and FIG. 8 also illustrate the tendon 30 near the raised grid element 114 of panel 11, and where a set of three tendons 30 extend along the grid element 116 between the 74, 76 edges. The three tendons of grid element 116 are equally spaced at a d3 distance from the face 16 of panel 11, preferably ¾ inch, and each one separated by d4, preferably 11 inch, and from each edge of the grid element 116. Note that in panels 10 and 11, the grid elements 112, 114 are raised T2, preferably 0.5 inch, and T3 across, preferably ¾ inch, while in panel 11, grid element 116 is raised T4, preferably 1.5 inches, and T5 across, preferably 5 inches, with T6 distance from the bottom of grid element 116 to the panel 11 edge 66, preferably 4 inches.

[0027] Referring, second, to FIGS. 9-12, there is therein illustrated a preferred embodiment of another feature of the invention comprising a corner column 80 and a linear column 50. FIG. 9 illustrates column 80, where top face 25A, bottom-up face 20, face 24, face 23, face 22, and face 21 are illustrated. FIG. 10 also illustrates column 80, but only the top face 25A, with preferred dimensions, including the overall dimensions of T7 by T8, preferably approximately 29 inches by 13 inches, with a cavity depth (for panel 10 and 11 insertion) of T9, preferably 12½ inch and a cavity width of T10, preferably 4 inches. The housing for the panel slot is T11, preferably 4½ inches thick, with a slot channel base of T12, preferably 3½ inches. FIG. 11 illustrates column 50, where top face 25B, bottom-up face 90, face 29, face 28, face 27, and face 26 are illustrated. FIG. 12 illustrates column 50, but only the top face 25B, with preferred dimensions, including the overall dimensions of T13 by T14, preferably approximately 32 inches by 13 inches, with a cavity depth (for panel 10 and 11 insertion) of T15, preferably 12½ inch and a cavity width of T16, preferably 4 inches. The housing for the panel slot is T17, preferably 4½ inches thick, with a slot channel base of T18, preferably 3½ inches.

[0028] Referring, second, to FIGS. 13 to 15, there is therein illustrated a preferred embodiment of another feature of the invention comprising column 50 and column faces 26, 28. FIG. 13 illustrates column 80, but only the column face 26, with locations of column face 25B, column face 29, column face 90, and column face 27. The column slot cavity has various dimensions T19 (with a dimension dependent on the desired height of a constructed wall), T20 (with a preferred dimension of 13 inches), T21 (with a preferred dimension of 5½ inches), T22 (with a preferred dimension of 4½ inches), T23 (with a preferred dimension of 4½ inches), T24 (with a preferred dimension of 4 inches), T25 (with a preferred dimension of 5½ inches), T26 (with a preferred dimension of 3 inches), T27 (with a preferred dimension of 5½ inches), T28 (with a preferred dimension of 2 inches), and T29 (with a preferred dimension of 6½ inches). FIG. 14 also illustrates column 50, column face 26, with locations of column faces 27, 29, 90, 25B. To the right of column 50 is a panel 10 with panel edge 70 and the location of panel edges 60, 62 and panel faces 12, 14. Above panel 10 are two panels 11. Each one has panel edge 74, and locations of panel edges 64, 66 and panel faces 12, 16. FIG. 15 illustrates two columns 50, each with three panels stacked within the column cavity. The column 50 to the left illustrates column face 28, and the locations of column faces 27, 29, 90, 25B. Of the stacked panels, the bottom-most is a panel 10, with a panel 11 resting upon a panel 10 with a grid element 116 (FIG. 8) of panel 11 sitting directly on panel 10's panel edge 60. Upon the panel 11 just mentioned is another panel 11, stacked in an identical way as discussed above, except, now, the second panel 11's grid element 116 rests upon the lower panel 11 panel edge 64. Additional panels 11 maybe stacked to achieve a desired height of a well with, likewise, extending the height of the columns 50, 80 to accommodate the extra panel height. Alternatively, the desired wall height may comprise a single panel 10 and appropriately-sized columns 50, 80.

[0029] Referring, third, to FIG. 16 to 17, there is therein illustrated a preferred embodiment of another feature of the invention comprising three columns 50 with two sets of stacked panels 10 and 11 resting between two columns 50 and one set of panels between a column 80 and a column 50. Each column 50 illustrates its panel face 29, while column 80 illustrates its column face 22. As illustrated in FIG. 15, the bottom-most panel in each stack is a panel 10 and each panel above it is a panel 11. FIG. 17 illustrates ten columns 50 and four columns 80 in a top view of a panel wall that totally surrounds an interior space. The illustrated top edges of the panels 11 are panel edges 64. The illustrated top of column 50 faces is column edge 25B and the top of columns face for columns 80 is column edges 25A. Note that the illustrated interior space could be a Passive House structure, that has no thermal bridging between its space and the columns 50, 80 or panels 10, 11.

[0030] Referring, fourth, to FIG. 18, there is therein illustrated a preferred embodiment of another feature of the invention comprising two columns 50, a panel 10 and panel 11. That figure is a photo of constructed panel 11 stacked upon panel 10, resting between tow columns 50, within each column's cavity.

[0031] Referring, fifth, to FIG. 19, there is therein illustrated a preferred embodiment of the invention, comprising the framing element 110, tensioning device 102, and cable 30 that is used to pre-tension the singular cable 30 through a panel 10 or panel 11. The preferred material of construction for framing element 110 is wood, size 2″ by 4″ and as long and wide as desired to produce the desired panel size. The exact spacing between the holes illustrated on framing element 110 faces 00, 02, 04, 06 are only important as they align to the precise holes of the rubber mold (not shown) into which the concrete mix for panel 10 and panel 11 is poured. The holes of framing element 110 faces 00, 02, 04, 06 align with the position of the wire rope 30 illustrated as described: a) Panel 10 in FIG. 3, panel edges 60, 62, 70, 72; b) panel 10 in FIG. 4, panel edge 60; c) panel 11 in FIG. 7, panel edges 64, 66, 74, 76; and d) panel 11, FIG. 8, panel edge 74 and grid element 116.Rubber Mold Feature Not illustrated

[0032] In both the Blount patent and the application herein, the mold device into which concrete is poured (see concrete recipe for panels 10, 11 below) are not illustrated. Such a device is typically composed of a rubber material, placed within the framing element 110 (for example) illustrated in FIG. 19, at the appropriate position so that the singular cable 30 becomes embedded at the depth into the panels 10, 11 identified in FIGS. 3, 4, 7, and 8 after the concrete is poured. The prestress force (about 40 pounds of tension) is not released until the concrete is fully cured, after about 48 hours.Alternative Uses for UTPSCCS Panel

[0033] The potential uses for the UTPSCCS panel are described below.

[0034] a) Exterior wall for a Passive House. In this application, the key feature is the separation of the exterior wall from the interior living spaces. Whenever materials of construction provide a pathway for heat transfer between outside climate conditions to interior climate-controlled conditions, the costs of maintaining a comfortable living space increase, due to the costs of heating, cooling, and / or humidity control. The Passive House exterior wall application for the UTPSCCS panel allows for a minimum of thermal bridging, to only those locations where there are windows and doors, and utility penetrations of the panel. See FIG. 18 for a depiction of this application.

[0035] b) Highway noise barriers, separation within a property, or the separation of multiple properties from the general public. In this application, the key feature is the linear panel and columns constructed to a desired height to control access or noise between a highway and a residential area. A benefit of the UTPSCCS panel over other similar wall designs is the relative ease of replacement, should a panel become damaged. This is so, as the panels may be raised out of their configuration and a replacement panel inserted to correct a defect as there are no fasteners. See FIG. 16 for a depiction of this application.Considerations for the Creation of the Product of the Invention

[0036] There are six considerations important to the preparation and manufacturing of items comprising this invention.

[0037] 1. For panels that are exposed to moist atmospheres, it is desirable that the cable be non-corrosive. In place of stainless steel wire rope, carbon fiber tendons or glass fiber tendons or others could be used. In any event, a tendon must have a surface suitable for forming a firm bond between the tendon and the concrete. The tendon material should also be strong enough to limit relaxation over time so as not to lose the prestress of approximately 40 pounds which has proven satisfactory.

[0038] 2. The concrete mix utilized should be one that will have durability under the climatic conditions to which the panel will be exposed such as freeze / thaw cycles, and should be resistant to shrinkage so that prestress will not be lost and the panel's architectural appearance will be maintained. To optimize the properties of the concrete, the aggregate size preferably should not exceed one half of the panel thickness (e.g., 14 inch) and the concrete mix should have a low water-cement ratio. See concrete recipe below.

[0039] 3. On account of the aggregates in the concrete mix, it is difficult to obtain a flat back face 14, 16 on panels 10, 11 respectively. So that a flat back face and flat panel grid elements 112, 114, 116 are obtained, the concrete mix (provided below) should be mixed first without the aggregates, and immediately placed within the rubber mold for panel 10 or panel 11, filling up the cavities for grid elements 112, 114, 116, creating a ⅛ inch covering for the produced panel faces 14, 16. Within 15 minutes of pouring the mix just described, the proper amount of aggregate is added to the concrete now remaining, mixed for uniformity, then poured upon what has already been poured. In this way, the surfaces of the rubber mold for panel 10, 11 are covered with the smooth cement and sand mixture before the aggregate has a chance to sink, placing the aggregate next to this cement-sand layer but not next to the rubber mold surface.

[0040] 4. Tensioning means are provided for applying tension to the wire rope during the casting and hardening of the panel. Referring more particularly in FIG. 19, the illustrated tensioning device 102 is arranged to apply tension to the single wire rope 30. The wire rope 30 is inserted into the tensioning device 102 suitably mounted to the framing element 110, then inserted into the hole on the framing element face 06 nearest the tensioning device 102, extending longitudinally to the hole on the other end of framing element 110, exiting framing element face 04, then reinserted into the framing element face 04 at the next hole of framing element 110, and repeating the above step at the other end of the framing element 110, where wire rope 30 re-enters framing element face 06, exits framing element 04, and then goes around framing element 110 to enter the nearest hole on framing element face 02, and continues this weaving action between framing element faces 02 and 00 until the wire rope 30 exits the second to the last hole nearest the tensioning device 102 on framing element 00, where wire rope 30 goes through framing element 110, exits framing element face 06 and enters the tensioning device 102 to join the other end of wire rope 30 so that the tensioning device 102 can simultaneously apply tension to both ends of wire rope 30, to about 40 pounds of tension. The steps outlined above provide the arrangement of the wire rope along the panel grid elements 112, 114, 116 positions illustrated in FIGS. 3, 4, 7, 8 as provided by a rubber mold (not shown). In this way, the exact positioning of the holes on frame element faces 00, 02, 04, 06 are not important, although the holes in the rubber mold next to the interior faces of the frame element 110 are critical to wire rope 30 positioning in the rubber mold prior to the pouring of the cement mix. The key to the weaving of wire rope 30 through the wooden frame element 110 is angling the wire rope 30 entrance and exit holes such that wire rope 30 never bends at a 90-degree angle, which may damage the wire rope 30 and cause failure when tension is applied.

[0041] 5. When the wire rope 30 is in place and the proper tension applied thereto, a concrete mix of desired composition may be poured into the mold. If desired, a texturing element may be applied upon the surface of the just-poured concrete mix. A vibrating device (not shown) may be used to flatten the wet concrete surface, before texturing if texturing is applied. In order to avoid warping of the cured concrete, framing element 110 and the poured concrete should not be moved while curing and the tension applied to wire rope 30 is not released until the concrete is fully cured. Various concrete curing techniques such as steam curing (i.e., an atmosphere of between 120-140 degrees F. for the first 18 hours of concrete curing) may be used if the ambient temperature of the concrete curing room cannot be kept consistent during the estimated 48 hour curing period. When the panel has developed sufficient strength, the tension on the wire rope 30 is released using wire cutters on the wire rope 30 at the tension device 102, then cut at the edges of the panels 10, 11 prior to removal from the rubber mold (not shown). The panels 10, 11 may be allowed to continue to cure in a moist environment for up to five days, thereby reducing the panel's resistance to shrinkage and maintain pre-stress.

[0042] 6. It is noteworthy to point out that the panel faces 14 and 16, with the gridded elements 112, 114, and 116 (waffle-like) are advantageous in that this design feature provides a higher strength to weight ratio than a flat faced panel without the grid.Recipe for UTPSCCS Panel Concrete

[0043] The concrete for the UTPSCCS panel is composed of: a) Portland Pozzolana Cement; b) sand; c) ¼-inch gravel (or similar material, such as recycled glass); d) water; and e) super plasticizer. Note that this recipe includes a melamine plasticizer, also known as polycarboxylate plasticizer, which can reduce the amount of water in the concrete mix by 15% to 20%, and increase the strength of the concrete.

[0044] The constituent ratio and weight of each material for the panel 10, 11 concrete mix are as follows: a) cement 2.4 lb or 1,104 g; b) sand 2.4 lb or 1,104 g; c) ¼-inch gravel 2.4 lb or 1,104 g; d) water 1.0 lb or 441.5 g; and e) super plasticizer 0.002 lb or 0.077 g. Without the cable 30, this mix weighs 8.2 pounds. But this 8.2 pounds of concrete mix will produce an approximate 2.5 square foot (by 0.5 inch thick) panel 10, 11, so the per square foot weight of the cured concrete is approximately 6.6 pounds.

[0045] Note: the recipe for the columns 50, 80 is not provided as it is not proprietary. Only the shape of the columns is proprietary with cavities and cavity protrusions illustrated in FIGS. 9, 10, 11, 12, 13, 14, and 15.

Examples

Embodiment Construction

[0024]The UTPSCCS has three unique features: a) Concrete panels that are thinner than commercially-available prestressed panels due to the raised grid pattern; b) a panel-in-slot (cavity) design that requires no bolts, no screws, nor any other fastener; and c) a free-standing shell that has no contact with an interior space (except at the minimal points where windows, doors, and utility penetrations are identified), thus drastically limiting heat transfer, i.e., thermal bridging. A detailed description of each figure is provided below. This section concludes with: a) Description of the rubber mold device not shown; b) alternate uses for the UTPSCCS panel; and c) the recipe for the concrete in the UTPSCCS panel (Part 1 of the patent). The recipe for the concrete in the linear and corner columns (Parts 2 and 3 of the patent) is not provided, as the appropriate recipe is not proprietary.

[0025]Referring first to FIGS. 1-8, there is therein illustrated a preferred embodiment of the inven...

Claims

1. Ultrathin, pre-stressed concrete panel that is thinner than commercially-available pre-stressed panels.

2. Panel-in-slot vertical column (i.e., column cavities) design that requires no bolts, screws, or fasteners to secure the panels, placed vertically into to the columns.

3. A free-standing, ultrathin, prestressed concrete exterior wall that has no contact with an interior space thus eliminating heat transfer (i.e., thermal bridging) when used as the exterior wall of a Passive House building.

Images