Patent Publication Number: US-2004040239-A1

Title: Prefabricated thin wall concrete panel

Description:
TECHNICAL FIELD  
       [0001] The present invention relates to a composite prefabricated concrete and insulating foam material panel, and including the method of fabricating a concrete wall utilizing such panels.  
       BACKGROUND ART  
       [0002] Various prefabricated or precast concrete wall panels are known for fabricating building structures or walls attached to the structure. The majority of known prefabricated concrete wall panels either utilize these panels as the exterior cladding, with a conventional inner wall being built adjacent an inner surface of the panel and insulated with conventional material, such as wool insulation, or insulated concrete wall panels having insulating polystyrene panels glued thereto. Most of the known prefabricated or precast concrete wall panels are for erection on foundation walls or to be attached to a structure. The assembly of precast concrete wall panels known in the art most often requires metal connectors that are welded together in order to interconnect the panels to a foundation or a structure and to each other. This is a time-consuming and expensive method of construction. Also, most known prefabricated concrete wall panels are very heavy and cumbersome to transport. Accordingly, only a few panels are transported on flatbed trucks at a time to a construction site, and this also adds to the cost of a building structure.  
       [0003] There is a need to provide prefabricated concrete wall panels that are insulated, lightweight, easy to manipulate, can be installed quickly in alignment and leveled, that have a finished texture on at least an outer surface or on both the outer and inner surfaces of the panel and wherein the panel can provide its own foundation or be easy to interconnect to a footing.  
       SUMMARY OF INVENTION  
       [0004] It is a feature of the present invention to provide a prefabricated concrete wall panel that provides the above needs.  
       [0005] Another feature of the present invention is to provide a prefabricated concrete wall panel that can be made with a plurality of exterior embossed finished surfaces and wherein the inner concrete wall panel may also have an interior finished surface and be provided with floor and roof connectors whereby to construct a building structure using a plurality of these panels.  
       [0006] Another feature of the present invention is to provide a prefabricated concrete wall panel and wherein an inner insulated foam material is adhered to the inside surfaces of opposed outer and inner concrete panel sections and adhered thereto by exposed fibers that are mixed with the concrete to form a composite concrete and insulating foam material bearing wall.  
       [0007] Another feature of the present invention is to provide a prefabricated concrete wall panel that is provided with connecting pins to support and interconnect the panel to a footing, a wall or a floor that is provided with aligned pin-locating holes having predetermined depths whereby to automatically level and align a plurality of panels together.  
       [0008] Another feature of the present invention is to provide a prefabricated concrete wall panel, with the outer or inner or both surfaces of the top section of the concrete panel having an embossed pattern provided with discrete construction material pieces and which may be casted with concrete of a different color to simulate real construction material pieces.  
       [0009] Another feature of the present invention is to provide a method of fabricating a wall structure utilizing prefabricated wall panels constructed in accordance with the present invention.  
       [0010] According to the above features, from a broad aspect, the present invention provides a prefabricated concrete wall panel comprising a bottom foundation section, adapted to be mounted at least partly underground, and a top wall section. The wall panel has an outer concrete panel section and an inner concrete panel section spaced from one another by an insulating foam material adhered to an interior surface of the panel sections. The wall panel has opposed flat parallel side walls and top and bottom end walls. The outer concrete panel section has an exterior finished surface.  
       [0011] According to a further broad aspect of the present invention, the prefabricated concrete wall panel is provided with footing-connecting pins projecting an equal predetermined length from the bottom end wall thereof and adapted to be received in pin-locating holes formed in a top surface of a footing or foundation and wherein said pin-locating holes are of predetermined depth to provide for auto-leveling and alignment of a plurality of the prefabricated concrete wall panels disposed side by side.  
       [0012] According to a still further broad aspect of the present invention, there is provided a prefabricated concrete wall panel comprising a bottom foundation section adapted to be mounted at least partly underground, and a top wall section projecting above ground. The top wall section has an exterior embossed patterned surface on at least one of an exterior or interior surface thereof. The wall panel has opposed flat parallel side walls and a top and bottom end wall. The bottom end wall has footing-connecting pins. The connecting pins project an equal predetermined length and are received on a top wall of a footing having pin-locating holes, which provides for automatic leveling and alignment of a plurality of prefabricated concrete wall panels disposed side by side.  
       [0013] According to a still further broad aspect of the present invention, there is provided a method of fabricating a wall structure utilizing prefabricated wall panels of the present invention. The method comprises providing a footing on a ground surface and drilling pin-locating holes having precise dimensions at predetermined locations along a top surface of the footing using a leveling instrument to determine the depth of said holes for installing a leveled panel. The said panel is positioned vertically on said footing with said footing-connecting pins projecting into complementary ones of said pin-locating holes and resting on a bottom end of the holes for self-leveling and alignment of a plurality of panels on said footing in side-by-side relationship. Once the panels and the pins are in place, the receiving holes are filled with epoxy which forms a “welding” between the side wall of the holes and the pins. 
     
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
     [0014] A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:  
     [0015]FIG. 1 is a front elevation view illustrating the configuration of a prefabricated concrete wall panel constructed in accordance with the present invention;  
     [0016]FIG. 2 is a cross-section view along cross-section lines II-II of FIG. 1;  
     [0017]FIG. 3A is a front elevation view of a prefabricated concrete wall panel constructed in accordance with the present invention, and having an embossed patterned outer surface provided with discrete pieces projecting from one of the side walls of the panel in alignment with complementary piece cavity located adjacent the opposite side wall on the outer surface of the panel;  
     [0018]FIG. 3B are elevation views showing two discrete patterned templates having casted material pieces simulating a plurality of stones and integrated together in the outer surface of the top wall section of the outer concrete panel section of FIG. 3A, with thin bricks or stones to be glued in depressions to dissimulate the joint between panels;  
     [0019]FIG. 4 is an elevation view showing a concrete wall panel incorporating therein window openings having window frames and mounted in the wall panel;  
     [0020]FIG. 5 is a fragmented elevation view of a prefabricated rectangular concrete wall panel, which is longitudinal in shape, and which is adapted for mounting directly on the top surface of a foundation wall; and  
     [0021]FIG. 6 is a schematic view showing a jig assembly for drilling pin-locating holes at predetermined locations along a top surface of a foundation or a footing. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
     [0022] Referring now to the drawings, and more particularly to FIGS. 1 and 2, there is shown generally at  10  the prefabricated concrete wall panel of the present invention. The wall panel  10  comprises a bottom foundation section  11 , which is adapted to be mounted at least partly under a ground surface  12 , as shown in FIG. 2, and connected to a footing  13 , as will be described later. The prefabricated concrete wall panel  10  also defines a top wall section  12 , which is formed integral with the bottom foundation section, in the preferred embodiment herein described. However, in a further embodiment, as illustrated in FIG. 7, only a top wall section  12  is provided that can be secured directly on a top surface of a foundation wall by the pin connections.  
     [0023] As better seen from FIG. 2, the concrete wall panel  10  is a composite panel having an outer concrete panel section  14  and an inner concrete panel section  15 . The panel sections are spaced from one another by an insulating foam material  16 , which is adhered to an interior surface  14 ′ and  15 ′ of the concrete panel sections  14  and  15 , respectively. As also herein shown, the foam material  16  has a greater thickness in the top wall section  12  than in the foundation section  11 , although this is not essential as the insulating foam material  16  can be of a constant width throughout.  
     [0024] Furthermore, and as illustrated in FIGS. 1 and 2, the prefabricated concrete wall is of substantially rectangular configuration and defines opposed flat parallel side walls  17  and  17 ′, and opposed parallel top and bottom end walls  18  and  19 , respectively. The outer concrete panel section  14  has an exterior embossed patterned surface  20  formed integral therewith to simulate an assembly of exterior finished construction material, such as stone, as herein shown, brick or wood boards, etc. The spacing between the embossed pattern pieces  20 ′ defines a joint  21 , which simulates a mortar joint.  
     [0025] The insulating foam material  16  is a polyurethane foam or other suitable insulating foam capable of being applied in a mold containing the panel sections and expanding therebetween and adhering to the inner surfaces  14 ′ and  15 ′ of the outer and inner concrete panel sections. However, to ensure better bonding of the foam to these panels, the concrete that is utilized to form these panel sections has fibers  22  mixed with the concrete. These fibers replace the reinforcing steel. These fibers may be applied to the concrete at the mixing stage to make sure it is uniformly distributed once the concrete is poured. The fibers can project from the inner surfaces  14 ′ and  15 ′, respectively. These fibers then bind with the foam material when it is injected between the panels to provide a stronger connection between the foam and the panel sections  14  and  15 . The adhesion between the foam, herein polyurethane, and the concrete is very strong, but can be made stronger by using glue on the inner surfaces of the panel sections  14  and  15 .  
     [0026] As herein shown, the concrete wall panel  10  is further provided with footing-connecting pins  23  that project from the bottom end wall  19  at a predetermined equal distance therefrom. As shown in FIG. 2, the footings  13  on which these panels are supported are also provided with pin-locating holes  24 , which are predrilled using a jig assembly, as will be described later with reference to FIG. 8. The pin-locating holes  24  may have different depths, depending on the level of the top surface  23 ′ of the footing  23 .  
     [0027] Referring now to FIGS. 3A and 3B, there is shown an embossed stone and brick pattern  20 ′ and  20 ″ respectively, on the outer surface  14 ″ of the outer concrete panel section  14 , whereby to simulate a stone wall. The stones and bricks  25  and  25 ′, are formed by two different templates. These pattern templates produce mortar joints  26  which delineate each of the discrete construction material pieces  27  and  27 ′. Concrete is poured over these templates, which are located against a bottom wall of a mold, not shown herein but obvious to a person skilled in the art.  
     [0028] As shown in FIG. 3A and 3B, some of the discrete material pieces  27  are missing along the opposed side edges  28  of the panel sections  14  and replaced by cavities  29 , or cavity portions, to receive thin material pieces  27 ″ adhesively secured in the aligned cavity portions  27 ″ of opposed wall panels, such as panels  10  and  10 ′ to bridge the abutting side edges of the panels. The material pieces  27 ″ provide a connection between the panels and camouflage the joints. It is also pointed out that these cavities  29  can also be formed in adjacent top and bottom end walls  18  and  19  when panels are laid one on top of another to also provide horizontal seam connections. When panels are to be laid one on top of another, the top wall  18  of the lower panel is provided with pin-locating holes of sufficient depth to receive the footing-connecting pin projecting from the bottom end wall of the uppermost panel. This provides quick and easy alignment.  
     [0029]FIG. 4 illustrates a still further embodiment of the prefabricated concrete wall panel  10 ″ and wherein the panel is provided with window and door openings  35  having different configurations. Also, the discrete material pieces in the embossed pattern can be of different sizes, whereby to simulate window ledges  36  and window crowns  37 , or any other decorative brick or stone pattern. The window frames and sashes may also be pre-mounted. Although not illustrated, the discrete material pieces can simulate wood planks disposed horizontally or vertically. It is also pointed out that, in the casting of the outer concrete panel section  14 , the templates disposed on the bottom surface of the mold can be filled with a colored concrete, thereby simulating certain material, such as red brick or grey brick, or colored planks, etc. After this concrete has set slightly, a second layer of concrete is poured binding to the first layer, delineating the discrete material pieces, so that when the panel section is pulled out of the mold the discrete pieces have one color and the joints  21  there-between will have the grey color of concrete simulating a motor joint.  
     [0030] As shown in FIG. 2, the outer surface  15 ″ of the inner concrete panel section  15  is provided with one or more floor joist connecting steel brackets  38 , which project from the outer surface  15 ″ thereof and which are provided for interconnecting a floor structure to surrounding vertical walls of a building structure formed by a plurality of these prefabricated concrete wall panels  10 . The inner concrete panel section  15  is further provided at a top end wall  18  thereof with a roof structure attachment bracket  39 . These brackets are attached to the concrete panels when casted by fasteners  39 ′ and  38 ′, respectively. Of course, if these panels are to be laid one on top of the other, it is only the uppermost panel that will be provided with this roof structure attachment brackets  39 .  
     [0031] As shown in FIG. 2, the panel  10  is further provided with transverse connecting rods  40  that are secured to and between the outer and inner concrete panels  14  and  15  and span the insulating foam material  16 . These transverse connecting rods  40  are connected to the panel sections  14  and  15  prior to the injection of the insulating foam  16  between the panel sections. These transverse connecting rods  40  also prevent deformation of the panel sections during their fabrication stage and thereafter. During extreme temperatures, the exterior skin can curve if it is not retained.  
     [0032] Referring now to FIG. 5, there is shown a prefabricated concrete wall panel  50  constructed in accordance with the present invention, but wherein the panel has a long span. As described above, the panels may have a multitude of dimensions. However, in the embodiment as shown in FIG. 5, the panel  50  only comprises a top wall section  51 , which is intended to project above the ground surface  52  or the top wall  53  of a foundation  54 . The top wall section  51  would also have an exterior embossed pattern surface  20 , as described above, and this would be provided on at least the exterior or interior surface thereof or on both surfaces, depending on the intended use of this panel. of course, in warm climates, the inner concrete panel section  15  may not have a surface material affixed thereto, and merely the concrete would be exposed to act as a finished interior surface.  
     [0033] The panel  50  has opposed flat parallel side walls  55  and  55 ′ and opposed parallel top end wall  56  and bottom end wall  57 . The bottom end wall is provided with footing-connecting pins  58  adjacent opposed ends thereof. As previously described, these connecting pins project a predetermined equal length and there are pairs of these pins adjacent opposed ends of the panels. These pins are disposed in pin-locating holes  59  provided in the top surface  53  of the foundation  54  and drilled with the jig assembly to provide auto-leveling and alignment. Of course, the foundation  54  may be merely a concrete footing if these panels are for mounting on soil that is not affected by frost, such as in warm climate areas. These wall panels  50  are mounted side by side and may be used to provide an elongated privacy wall. In the particular embodiment as described with respect to FIG. 5, the walls are solid concrete walls and do not have an insulating center core.  
     [0034] It is also preferred that the prefabricated concrete wall panels, as described above, when mounted on a footing or foundation wall, be further provided by a grout joint  60  (see FIG. 2), which is disposed in a lower space between the bottom end walls  19  of the concrete panels and the top surface  23 ′ of the footing  13 . The grout can be applied on the bottom end wall of the panel about the pins  23  prior to positioning the panels on their foundation. A cement pad  61  is also disposed in the gap between the bottom end walls  19  of the panels  10  and the top wall  23 ′ of the footings  23  to seal this lower space.  
     [0035] The method of fabricating a wall structure utilizing prefabricated wall panels  10  of the present invention comprises essentially the steps of providing a footing on a ground surface or providing a foundation  70 , as illustrated in FIG. 6. Drilling jigs  71  are disposed at predetermined locations on the top surface  72  of the foundation wall  70 , and a drill or drills  73  are placed in operation whereby to drill pairs of holes  24  of predetermined depth. A further jig  74  is then installed over the drilled holes  24  and, with the use of a laser device  75 , ensures the proper location of the drilling jig  71  at a predetermined distance, on the footing, from the holes  24 , whereby to drill a second pair of holes  24 ′ at a precise distance to match the distance between the sets of pins  58  projecting from the lower surface of the specific panels to be installed on the foundation wall. The laser instrument  75  is a leveling instrument and also determines the depth at which the second holes  24 ′ must be drilled whereby to ensure that the panels to be supported in these holes on their pins  23  are substantially perfectly leveled and also perfectly aligned longitudinally. Further holes are drilled adjacent each panel location to support adjacent panels. The adjacent panels are disposed on the foundation wall  70  with their connecting pins projecting into complementary ones of the pin-locating holes  24  and resting on the bottom ends  24 ″ of these holes. The depths of the holes vary depending on the level of the top surface of the footing or foundation whereby to support leveled panels. An epoxy sealant material  60 , as previously described with reference to FIG. 2, is applied about the pins  23  against the bottom end wall  19  of the panel to seal the footing-connecting pins to the top surface of the footing to prevent humidity infiltration and rust. A cement grout  61  is disposed in any space between the top surface  72  of the footing  70  and the bottom end wall  19  of the panels to reinforce the connection therebetween and to seal that space. Another coat of sealant material, such as tar, may also be applied to the outside wall of the foundation section  11 , particularly if the foundation section is buried in the ground. Although not shown, the vertical joints between the panels intended to be in the ground would also be sealed with a geotextile canvas or other sealant materials, not shown herein but obvious to a person skilled in the art.  
     [0036] Although not shown, electrical pipes or conduits are put in place within the wall whereby to be wired on site. If the inner surface is to form a finished surface, then nailing spots or convenient attachments can be put in place at specific locations to install curtains, blinds or to install anything on the wall inner surface, such as paintings, frames, etc.  
     [0037] It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.