Abstract:
A method for using tilt-up panels with chamfered sides, extensions below the panels ad receptacles for removable eyelets approximately ⅔ of the way up the panel. Inserts may be used between the panels to hold epoxy or other materials. The inserts may include a T-shaped form that obviates the need for caulking between the outside portions of the panels.

Description:
BACKGROUND OF INVENTION 
   1. Field of the Invention 
   This invention relates generally to building construction procedures and equipment, and more particularly to a tilt-up concrete wall panel and a method for using it. 
   2. Description of Related Art 
   Tilt-up concrete wall panels are well known in the art. They facilitate building construction in the prior art, in which workers fabricate the panels at the building site and tilt them up into position to form the walls. Concrete wall panels of this type are generally limited in size because the stress of placement of these walls may cause them to break or crumble during the lifting process. 
   There are several disadvantages associated with tilt-up panels as they presently are used. During construction, structures formed by tilt-up panels are subject to being destabilized. Also, because panels in the present art are structurally deficient and cannot stand the rigors of transport, they must be manufactured on the construction site. The structural deficiency also prohibits the use of tilt-up panels for tall structures. In addition, current structures made with tilt-up panels may be subject to shearing forces that can weaken a structure. Moreover, there are no tilt-up panels which are designed to provide spacing for material to fill between tilt-up panels. Also, there are no tilt-up panels which use weld plates on the top, sides and bottom which may be used to provide increased support in a resulting structure. In addition, joints covers are not used which can protect seams between panels. 
   There is also a need for a panel specifically made to optimize the accommodation of an insert between tilt-up panels. The inserts help stabilize the panels, reduce the amount of shear on the panels, and serve as a plug between the panels so that an appropriate material may be filled between two panels. The inserts also may operate to serve as a gasket against water intrusion and an expansion joint between panels. Also, there is a need for a panel that has receptacles for removable lifting means, such as eyelets, as well as extensions below the panels, to allow large panels to be accurately placed during construction of a structure. In addition, there is a need for a panel with pre-constructed block-outs to allow conduit to run within support columns of a structure. Also, there is a need for panels with increased reinforcement within the inner side of support columns. The reinforcement would allow lifting means in mechanical communication with the increased reinforcement to be able to lift a panel without bending, weakening or breaking the panel. There is also a need for panels with weld plates on the sides so that adjacent panels may be securely welded together. There is also a need for a panel with increased strength so that the panels may reliably be manufactured off-site and transported to the construction site. Conventional tilt-up panels have not had these features which would improve the reliability of structures, increase the number of uses for tilt-up panels in the construction industry, decrease cost of production and increase speed of construction. 
   It may also be desirable with the construction of some buildings by tilt-up concrete wall panels to provide for a system with block-outs for running conduit throughout it. U.S. Pat. No. 6,182,416 to Brackin discloses a method for fabricating a tilt-up concrete wall panel at the building with removes that require nail holes to be placed in a concrete slab. U.S. Pat. No. 5,609,005 to Schierloh, et al., teaches a tilt-up panel with an offset anchor secured into the foundation for the structure. U.S. Pat. No. 4,659,057 to Felter teaches a system for forming concrete tilt-up wall panels that are lifted from points on the outer surface of the support columns, providing a design prone to crumbling. 
   In new construction, tilt-up wall panels are used for a variety of applications where the walls are relatively low. What is needed in the art is a tilt-up panel that is strong and sturdy enough to be manufactured off site and used for tall structures. A need exists for a panel for forming a structure with enhanced ability to resist shearing forces and improved expansion joints. A need also exists for a panel lifting system to allow long panels to be placed properly in forming a structure. A need also exists for a panel with block-outs for conduit and intrinsic structure for attaching drywall. Also, a need exists for a tilt-up wall system that uses an insert between panels and a joint cover at seams. It is therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed. 
   SUMMARY OF INVENTION 
   In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a front elevation view of the preferred embodiment of the invention. 
       FIG. 2  is a cross sectional top view of the invention. 
       FIG. 3  is a cross sectional side view of the lower portion of the preferred embodiment of the invention. 
       FIG. 4  is a cross sectional side view of the lower portion of the preferred embodiment of the invention in place on a footer. 
       FIG. 5  is a cross sectional top view of one embodiment of the invention with an insert between the panels. 
       FIG. 6  is a top view of a form for a panel. 
       FIG. 7  is a cross sectional view of a form for a panel showing the form attached to a secure surface. 
       FIG. 8  is a bottom view of a form for a panel. 
       FIG. 9  is a cross sectional view of a form for a panel. 
       FIG. 10  is a cross sectional view of an alternative embodiment of an insert for placement between panels. 
       FIG. 11  is a side view of an alternative embodiment of an insert for placement between panels. 
       FIG. 12  is a sectional view of an alternative embodiment of an insert in situ between two panels. 
   

   DETAILED DESCRIPTION 
   The present invention is a panel for tilt-up wall construction of a high strength structure, shown generally at  10  in  FIGS. 1 and 2 . The panel  10  is preferably made of concrete, approximately twelve feet long and about thirty feet high. As shown in  FIG. 2 , each panel is preferably reinforced by wire mesh  12 . It is preferred that the mesh is 6×6×4−4, and made of iron. The concrete panel  10  formed around the mesh  12  is approximately three inches in depth. Furthermore, it is preferred that each side of the panel  10  comprises a chamfered edge  14 , as shown in  FIG. 5 . 
   Each panel also includes intrinsic columnar supports  16   a ,  16   b . As shown in  FIG. 2 , it is preferred that a panel  10  has at least one interior columnar support  16   a  and an exterior columnar support  16   b  on each side. The supports  16   a ,  16   b  generally run the height of the panel  10 . 
   The columnar supports  16   a ,  16   b  are each reinforced internally by a means for reinforcing the supports centrally, preferably by one or more metal reinforcement bars  18 ,  20  generally running the height of each columnar support  16   a ,  16   b . As shown in  FIG. 2 , preferably, in each columnar support  16   a ,  16   b  of each panel  10  is at least an inner bar  18  and an outer bar  20 . However, additional bars may be preferred for additional strength. In the preferred embodiment, for the interior columnar supports  16   a , it is preferred that the inner bar  18  is especially strong and is rigid for improved strength during the tilt-up operation. For example, in the preferred embodiment the inner bar  18  is #8 rebar, and the outer bar  20  is #6 rebar. However, for the outer column supports  16   b , which do not bear the stresses of the inner columnar supports  16   a  during the tilt-up operation, both the inner bar  18  and the outer bar  20  may be the same strength, such as #6 rebar. It is preferred that the columnar supports  16   a ,  16   b  are about three and ⅝ inches deep and approximately eight inches wide, to accommodate framing for drywall and insulation in the interior of the structure. Furthermore, this configuration forms areas for the placement of insulation, if wanted, and drywall or other interior finishing material, removing the need for a furring strip for the drywall or other finishing material. In this configuration, the insulation is preferred to be R11 fiberglass insulation. However, other insulation may be used in the alternative. 
   Also, it is preferred that panel  10  comprise a receptacle  46  for a removable means for lifting the panel  10  and for facilitating placement of the panel, located approximately two-thirds up the height of the panel  10 , on interior columnar supports  16   a . However, depending upon the size of the panel used, the type and number of cutouts in the panel, and other construction factors, the height of the receptacle may be adjusted. Preferably, the receptacle  46  is a fitting for a removable eyelet  48 , as shown in  FIGS. 1 and 2 . Preferably the receptacle  46  and the eyelet  48  have corresponding threads. 
   It is also preferred that the columnar supports  16   a ,  16   b  comprise one or more block-outs  22  for conduit to run. Optimally, the block-outs  22  are located approximately sixteen inches above the bottom side of the, panel  10 . The block-outs may run through the exterior columnar supports  16   a , as well as the interior columnar supports  16   b . For panels  10  of approximately thirty feet in height, a separate set of block-outs  22  may be formed approximately thirteen feet above the bottom of the panel, as shown in  FIG. 1 . Among other reasons, this distance optimizes the location of conduit such as telephone cable or electrical wiring to be run on a second floor to the finished structure. Other block-outs  22  may be made into the columnar supports  16   a ,  16   b , depending upon the use of the structure. Also, one or more stud embeds  26  may be formed in the interior and exterior columnar supports  16   a ,  16   b , as shown in  FIG. 2 . These embeds  26  optimize attachment points for drywall onto the inside surface of the panel  10 . 
   For the tilt-up operation, it is critical that the panels  10  are placed correctly. As shown in  FIGS. 3 and 4 , the panels  10  include a plurality of extensions  28  extending vertically from the bottom side  24  of the panel  10  appropriate for placement of the panel  10  into a footer  30 . Each extension  28  fits within a core hole  32  in the footer  30 . Preferably, the core hole  32  is approximately two inches in diameter and seven inches in depth. It is also preferred that the extensions  28  are extensions of the inner bars  18  within the columnar supports  16   a ,  16   b , as shown in  FIG. 3 . The extensions  28  should be approximately six inches in length. 
   In one embodiment of the invention, as shown in  FIG. 5 , at least one plastic insert  34  is placed between two panels  10 . The insert  34  is generally shaped to correspond with the chamfer  14  in the side of each panel  10 . The insert  34  may be constructed in the form of a pin  34 . In the preferred embodiment, the insert  34  is approximately twenty-four inches long. However, the insert  34  may be any length, or extend fully up the length of the wall. It is also preferred that the insert  34  is made from a high-density, high compressive strength plastic. The insert  34  is placed approximately midway up between the panels  10 . It is attachable to the panels by a double sticky tape  36  to keep it in place during construction of the structure; however, other methods of attaching the insert  34  to the panels  10  are known, such as an adhesive or epoxy. The insert  34  serves to act as a stabilizer against shear between the panels  10 , and also serves to help keep the panels  10  aligned. Moreover, the insert  34  may operate as a gasket where it is approximately the full height of the two panels  10 . Furthermore, the insert  34  preferably expands and contracts according to the temperature. Thus the insert  34  acts as an expansion joint between the two panels  10 . In addition, the insert  34  may function as a plug for filling material between the panels  10 . Material may include epoxy, cement or other material depending upon the qualities desired for the joint between the panels  10 . Caulking  38  at the joint keeps filler material in and makes the joint look professionally finished. It may also be desired to have a second insert  34  or pin  34  approximately twenty-four inches from the top of the panels  10  for increased stabilization and a more sure alignment between the panels  10 . In another alternative embodiment, a pre-formed joint cover may be used between the panels. 
   Also, as shown in  FIGS. 3 and 4 , to further ensure proper and secure placement, a bottom weld plate  40  is tied to the inner reinforcement bar  18  at the bottom portion of the columnar supports  16   a ,  16   b . The bottom weld plate  40  is then welded to a corresponding plate  42  in the footer. It may then be preferred to provide caulking  44  at the seam between the foot of the panel  10  and the foot of the footer  30 . 
   A structure built in accordance with the present invention is preferably made as follows. First panels  10  are formed, each including a plurality of columnar supports  16   a ,  16   b , extensions below the panel  28 , and intrinsic receptacles  40  for a means for lifting the panel  10 , such as an eyelet  48 . Forms  58  for the creation of the panel are illustrated in  FIGS. 6 through 9 .  FIG. 7  illustrates how the form is secured to a surface during formation of the panels  10 . Block-outs  22  formed at the formation of the panel  10  within the form, or may be carved into the columnar supports  16   a ,  16   b  after the panel  10  is formed. As the panel  10  is formed, or after it has cured, any number of facades may be imprinted on or attached to the outer surface of the panels. For example, the concrete may be stamped with a repeating or one-time aesthetic pattern; river rock or other aggregate may be affixed to the panel or liners or channels may be formed onto the outer surface of the panel. 
   A footer  30  is provided, comprising core holes  32  complementary to the extensions  28  below the panel  10 . At least one of the core holes  32  is then filled at least part way with a suitable filling material  52 , such as grout, to help form a seal between the panel  10  and the footer  30 . The filling material  52  may also be cement, for added strength, or other material, depending upon the structural properties preferred by the builder. It may also be preferable to lay a bed of grout between the rod holes in the footer  30  to create a seal between the panel  10  and the footer  30 . Depending upon the grout material, the seal may operate as a seal for water intrusion or an insect barrier, or both. Also, before the panel  10  is placed on the footer  30 , shims  50  are preferably placed between the panel and the footer. The shims  50  ensure that the panels  10  are properly aligned. These shims  50  are preferably made of a material of high compressive strength. Also before the panel  10  is positioned, the eyelets  48  are placed in the receptacles  46 . The panel  10  is then positioned over the footer  30 , using at least one of the extensions  28  and at least one of the eyelets  48 . The panel  10  is then placed on the footer  30  so that the extensions  28  are located in the core holes  32  of the footer  30 . The extensions  28  displace the filling material  52  in the core holes  32  in the footer  30 , so that the filling material  52  forms a seal between the panel  10  and the footer  30 . Bracing  54  as known in the art is then added as necessary to temporarily stabilize the structure. Before a second panel  10  is placed, an insert  34  is attached to the panel  10  approximately midway up the panel  10 . The insert  34  is attached to the chamfered edge  14  of the first panel  10  by double sided tape  56 . The second panel  10  is placed next to the first, in substantially the same manner as the first, in contact with the insert  34 . Appropriate filling material, such as caulking epoxy or cement  15 , may then be placed over the insert  34 . It is preferred that the caulking be in contact with the insert. 
   In an alternative embodiment, a columnar insert  34  is used, shown in  FIGS. 10 through 12 . In this embodiment, the insert is preferably hollow. The insert  34  has a central faceted portion  60 , connected to an inner arm  62  and an outer T-shaped form  64 . The insert  34  is placed between two panels  10  so the inner arm  62  is on the same side as the inner side of the panels  10  and the outer form  64  is on the outer side of the panels. The insert  34  is placed so the outer forms  64  are located outside the panels  10  as shown in  FIG. 12 . Thus, caulking  44  is only needed between the outside surface of the panels, and may be preferred between the insert and the chamfered edges of the panels  10 . As shown in  FIG. 10 , it is preferred that the faceted portion  60 , the inner arm  62  and the base of the outer form  64  are hollow. However, they may also be made solid throughout.