Abstract:
A reinforcement bar support system transfers forces perpendicular to a wall to a surrounding frame while permitting movement of the wall with respect to the frame in the direction of the plane of the wall and in the vertical direction. A bar is built into the wall. The apparatus includes a brace that is attached to the frame and a face that projects from the brace. Flanges extend outwardly from the face to receive the bar and limit movement of the bar with respect to the frame in the direction perpendicular to the wall.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to a reinforcement bar support system, and more particularly, to a system that transfers forces perpendicular to a wall from a vertical reinforcing bar or post-tensioning rod to a surrounding frame while permitting vertical and horizontal movement of the wall with respect to the frame in the direction of the plane of the wall. 
     2. Description of the Related Art 
     Various types of anchors are known for stabilizing walls to other walls, floors, or beams. These anchors often allow for vertical movement of the wall with respect to another wall, floor or beam. Several fixed anchors for use with an overhead frame typically are embedded in masonry mortar head joints or bed joints, and therefore limit horizontal movement of the wall in all directions with respect to the frame. Such anchors can cause problems with forces in the plane of the wall resulting from seismic activity, volume changes due to temperature drying shrinkage, carbonation or other phenomenon. In particular, it has been found that when such anchors are used, these forces can result in separation of the wall from the surrounding frame. 
     In addition, there are anchor assemblies that are embedded into mortar joints or grout-filled cells in masonry that allow in-plane wall movement while resisting forces perpendicular to the plane of the wall. These assemblies are used where there is no vertical reinforcement in the wall that needs to be anchored at its ends. 
     Thus, it would be desirable to have an apparatus that can be used to transmit forces in a direction perpendicular to a wall from the wall to the frame while permitting vertical and horizontal movement of the wall with respect to the frame when used in conjunction with a reinforced or prestressed masonry wall. 
     SUMMARY OF THE INVENTION 
     The present invention is an apparatus for attaching reinforced or prestressed masonry to its supporting frame or other structural element by receiving and encapsulating a bar built into a wall. The apparatus transfers forces in a direction perpendicular to the plane of the wall from the wall to the frame or other structural element while allowing in-plane movement of the wall with respect to the frame. The apparatus generally includes a first means for attaching the apparatus to the frame and a second means connected to the first means for receiving the bar and limiting movement of the bar with respect to the frame in one axis while permitting movement of the bar in two other axes. In particular, the second means can limit movement of the bar in a direction perpendicular to the plane of the wall while permitting movement in the plane of the wall. 
     More specifically, the apparatus of the present invention preferably includes a brace defining at least one adjustment slot, a face projecting from the brace and a first flange extending outwardly from the face, the first flange limiting movement of the bar. The brace is attached to the frame. The brace preferably has two parallel adjustment slots. Preferably, the apparatus also includes a second flange extending outwardly from the face opposite the first flange such that the first and second flanges define a bar receiving area. The first and second flanges each can have one end connected to the face and opposite ends that are independent of one another. The first and second flanges can be formed from the face. Alternatively, a separate piece forming the flanges can be attached to the face. The first flange preferably extends parallel to the second flange. Both the first and second flange can extend substantially perpendicular to the face. In an alternative embodiment, the first flange can diverge from the second flange, e.g., to define a truncated V-shaped bar receiving area. Both the brace and the face can be planar with the face perpendicular to the brace. 
     In an alternative embodiment, the apparatus includes a first planar brace defining a first adjustment slot, a second planar brace defining a second adjustment slot, a face projecting from the first and second braces and a first flange extending outwardly from the face. The first flange limits movement of the bar. The first and second brace can be coplanar. In this embodiment, the apparatus also can include a second flange extending outwardly from the face opposite the first flange such that the first and second flanges define a bar receiving area. The first and second flanges each have one end connected to the face and opposite ends that are independent of one another. The first and second flanges can be formed from the face. The first flange can extend substantially parallel to the second flange. The first and second flange can extend substantially perpendicular to the face. Alternatively, the first flange can diverge from the second flange. The first and second flanges can define a truncated V-shaped bar receiving area. The face preferably is perpendicular to the first and second braces. 
     In another alternative embodiment, the apparatus is used in conjunction with a plurality of bars. In this embodiment, the apparatus includes a brace defining at least one adjustment slot, a face projecting from the brace and a plurality of flanges extending outwardly from the face. The flanges limit movement of the bars. The brace can alternatively define a plurality of adjustment slots which can be parallel. Each successive pair of flanges can limit movement of a respective one of the bars. The first and second flange of at least one of the successive pairs of flanges has one end connected to the face and opposite ends that are independent of one another. The first and second flanges can be formed from the face. The first flange can extend substantially parallel to the second flange. The first and second flanges can extend substantially perpendicular to the face. Alternatively, the first flange diverges from the second flange. In this case, the first and second flanges can define a truncated V-shaped bar receiving area. The brace and the face can be planar with the face perpendicular to the brace. In other embodiments, three or four flanges may be included. In alternative embodiments, the flanges extend in a plane perpendicular, rather than parallel, to the longitudinal axis of the bar. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a frame and masonry wall with the frame partially broken away to illustrate a reinforcement bar system; 
     FIG. 2 is a perspective view of an apparatus of the present invention used in conjunction with a cell of a masonry wall having a vertical post-tensioning bar; 
     FIG. 3 is a perspective view of an apparatus of the present invention used in conjunction with a cell a masonry wall having a vertical reinforcement bar; 
     FIG. 4 is a alternative embodiment of the apparatus of the present invention; 
     FIG. 5 is a second alternative embodiment of the apparatus of the present invention; and 
     FIG. 6 is a third alternative embodiment of the apparatus of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first to FIG. 1, there is shown a masonry wall  10  made from a plurality of masonry units  12  and bounded by a frame  14 . It is desirable to transfer forces in a direction perpendicular to the plane of wall  10  to frame  14  through a vertical reinforcement bar or post-tension rod. In FIG. 1, frame  14  is partially broken away to show an apparatus  16  in accordance with the present invention. As shown in FIGS. 2 and 3, apparatus  16  can be used in conjunction with a vertical post-tensioning bar  18  or vertical reinforcement bar (or rebar)  20  to transfer forces perpendicular to the plane of wall  10  to frame  14 . Apparatus  16  advantageously encaptures the vertical reinforcement bar  20  and allows for vertical movement of wall  10  with respect to frame  14 . Apparatus  16  also allows for in-plane movement of wall  10  with respect to frame  14 . 
     Turning now to FIG. 2, there is shown apparatus  16  for use in conjunction with vertical post-tensioning bar  18 . Apparatus  16  generally includes a brace  22  and a face  24 . Brace  22  can include at least one, and preferably two, adjustment slots  26 . Adjustment slots  26  receive suitable attachment means, such as expansion anchors, powder driven anchors or bolts or some other fastener, (not shown) for attaching brace  22  to frame  14 . An alternative method is to field weld brace  22  to a steel frame. Slots  26  preferably are parallel to each other to provide additional adjustment in the plane of the wall. Face  24  includes at least one, and preferably two, flanges  28  extending outwardly from face  24  to define a bar receiving area  30 . Flanges  28  limit movement of bar  18  in a direction perpendicular to wall  10 . Flanges  28  preferably are formed from face  24  and each flange  28  has a first end  32  connected to face  24  and a second end  34  independent of the other flange  28 . Alternatively, flanges  28  can be part of a separate u-shaped channel that is attached to a solid face  24  by welding for extra strength. Flanges  28  preferably extend substantially parallel to one another as shown in FIG.  2 . However, other configurations of flanges  28  can be used, if desired. For example, flanges  28  can diverge from one another, e.g., to form a truncated V-shaped or trapezoid-shaped bar receiving area  30  to accommodate different size bars  18  with the same apparatus  16 . Alternatively, a single flange can be used that is shaped so as to define an appropriate bar receiving area. 
     FIG. 3 shows apparatus  16  in use in conjunction with a vertical rebar  20 . Vertical rebar  20  can be used with a hollow masonry unit  36  which has a cell  38  filled with concrete or grout  40 . Apparatus  16  can be identical to that depicted in FIG.  2 . Apparatus  16  preferably is made from steel. Apparatus  16  should be of such size that face  24  fits within the width of the masonry unit. Also, apparatus  16  should not be larger than the height of the masonry unit. 
     An alternative apparatus  16 ′ is shown in FIG.  4 . Apparatus  16 ′ generally includes a first planar brace  42 , a second planar brace  44  and a face  46 . Brace  42  defines a first adjustment slot  48  and brace  44  defines a second adjustment slot  50 . Brace  42  and brace  44  are coplanar. Face  46  is similar to face  24  and includes flanges  52  similar to flanges  28 . 
     Another alternative apparatus  16 ″ is shown in FIG.  5 . Apparatus  16 ″ generally includes a brace  54  and a face  56 . Brace  54  can define at least one adjustment slot  58 . A plurality of flanges  60  extend outwardly from face  56 . Each successive pair of flanges  60  limits movement of one bar, such as post-tensioning bar  18  or rebar  20 . Other flange configurations also are possible. For example, instead of having two flanges for each bar, there could be a total of N+1 flanges for every N bars. Thus, three flanges could be used to receive two bars, with the first bar housed between the first and second flanges and the second bar housed between the second and third flanges. 
     Yet another alternative apparatus  16 ′″ is shown in FIG.  6 . Apparatus  16 ′″ generally includes a brace  70  and a face  72 . Brace  70  can include at least one adjustment slot  74 . A plurality of flanges  76   a-d  extend outwardly from face  72  in a direction generally perpendicular to the previously described embodiments. Thus, flanges  76   a-d  extend in a plane perpendicular, rather than parallel, to the longitudinal axis of the bar. Flanges  76   a-d  define a bar receiving area  78 . Flanges  76   a  and  76   b  are generally coplanar. Flanges  76   c  and  76   d  also are generally coplanar. As shown in FIG. 6, flanges  76   a  and  76   c  are on a first side of bar receiving area  78 , while flanges  76   b  and  76   d  are on an opposite side of bar receiving area  78 . Alternatively, three flanges can be used, with two flanges on one side and the third flange on the opposite side of bar receiving area  78 . Thus, for example, flange  76   c  in FIG. 6 could be eliminated. In that case, flange  76   a  preferably would be located in a lower position than that shown in FIG.  6 . In particular, flange  76   a  would be positioned higher than flange  76   d  but lower than flange  76   b.    
     Now that several possible configurations of apparatus  16  have been demonstrated, a brief discussion of the method for building a framed wall using apparatus  16  will be given. Initially, the ceiling or frame  14  is installed. Masonry units  12  then are installed to begin construction of wall  10  and rebars  20  (or post-tensioning bars  18 ) are inserted. Rebars  20  (or post-tensioning bars  18 ) are installed during the construction of the wall and extend almost to the bottom of frame  14  so that as frame  14  deflects downwardly there will be no interference. Generally, rebar  20  (or post-tensioning bar  18 ) extends one-half of the height of a masonry unit above the next to last unit to be installed. Wall  10  is built up short of its full height near apparatus  16 . Apparatus  16  is then attached to frame  14  by placing anchors or bolts through adjustment slots  26  or welding apparatus  16  to frame  14 . Apparatus  16  is adjusted to place flanges  28  around rebar  20 . The masonry unit  12  directly below brace  22  is then inserted. Upon completion of the construction of wall  10 , apparatus  16  serves to transfer forces in a direction perpendicular to wall  10  to frame  14 , while allowing wall  10  to sag and deflect vertically as well as to move in the plane of wall  10  with respect to frame  14 . 
     Whereas the present invention has been described with respect to specific embodiments thereof, it will be understood that various changes and modifications will be suggested to one skilled in the art and it is intended that the invention encompass such changes and modifications as fall within the scope of the appended claims.