Patent Publication Number: US-11041278-B2

Title: Connection assembly

Description:
FIELD OF THE INVENTION 
     The present invention relates to a connection assembly and, more particularly, to a connection assembly connecting a first concrete member to a second concrete member. 
     BACKGROUND 
     In the formation of various concrete structures, adjacent concrete members are attached to each other. In an exemplary orientation, a concrete wall is attached to a concrete walkway positioned on top of the concrete wall. The walkway has an opening and the wall has a portion extending into the opening. The connection between the walkway and the wall is commonly formed by casting a concrete cap around the portion of the wall that is disposed within the opening of the walkway. 
     The wall and the walkway undergo thermal expansion and contraction over the lifetime of the concrete structure. The concrete cap, however, is cast to fill the opening in the walkway; the concrete material of the concrete cap abuts both the wall and the walkway in a state prior to any expansion or contraction. The thermal expansion and contraction consequently creates stresses in the concrete material of the cap, the wall, and the walkway, which impair the strength of the concrete elements and decrease the useful life of the concrete structure. 
     SUMMARY 
     A connection assembly includes a first concrete member, a second concrete member, and a cap formed of a concrete material. The first concrete member has an end surface and a plurality of reinforcing bars protruding from the end surface. The second concrete member has a plurality of opening walls defining an opening extending through the second concrete member. The second concrete member is disposed on the end surface of the first concrete member with the reinforcing bars disposed in the opening. The cap is cast in the opening around the reinforcing bars and is spaced apart from each of the opening walls. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described by way of example with reference to the accompanying figures, of which: 
         FIG. 1  is a sectional side view of a connection assembly according to an embodiment; and 
         FIG. 2  is a top view of the connection assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
     Exemplary embodiments of the present invention will be described hereinafter in detail with reference to the attached drawings, wherein like reference numerals refer to like elements. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will convey the concept of the disclosure to those skilled in the art. In some of the drawings, like reference numerals may be omitted for some of multiple like elements in order to maintain clarity of the drawings. 
     A connection assembly according to an embodiment, as shown in  FIGS. 1 and 2 , comprises a first concrete member  10 , a second concrete member  20  disposed on the first concrete member  10 , a cap  40  connecting the first concrete member  10  to the second concrete member  20 , and a pair of shims  50  disposed between the cap  40  and the second concrete member  20 . 
     The first concrete member  10 , as shown in  FIGS. 1 and 2 , includes a first concrete body  12  and a plurality of reinforcing bars  16  disposed in and protruding from the first concrete body  12 . In the shown embodiment, the first concrete member  10  is a precast wall. 
     The first concrete body  12 , in the embodiment shown in  FIGS. 1 and 2 , is an elongated rectangular member extending along a longitudinal direction Y. The first concrete body  12  has a height extending along a vertical direction Z perpendicular to the longitudinal direction Y and a width extending along a lateral direction X perpendicular to the vertical direction Z and the longitudinal direction Y. As shown in  FIG. 1 , the first concrete body  12  has an end surface  14  in the vertical direction Z. In the shown embodiment, the end surface  14  is roughened; the end surface  14  is rougher than other surfaces of the first concrete body  12 . The first concrete body  12  can be formed of any mixture of cement, water, and aggregate known to those with ordinary skill in the art and used in concrete walls. 
     As shown in  FIG. 1 , the reinforcing bars  16  each have an embedded portion  17  disposed within the first concrete body  12  and a protruding portion  18  protruding from the end surface  14  of the first concrete body  12  in the vertical direction Z. In the shown embodiment, each of the reinforcing bars  16  is formed in a U-shape, with a curve of the U-shape forming the protruding portion  18 . Although only one reinforcing bar  16  is shown in  FIG. 1 , the plurality of reinforcing bars  16 , as shown each with a dashed line in  FIG. 2 , are aligned along the length of the first concrete body  12  and spaced at an interval in the longitudinal direction Y. The reinforcing bars  16  may be formed of any material commonly used for reinforcement in precast concrete structures. In an embodiment, the first concrete member  10  is precast prior to being used in the connection assembly, with the reinforcing bars  16  precast within the first concrete body  12  in the arrangement shown in  FIG. 1 . 
     The second concrete member  20 , as shown in  FIGS. 1 and 2 , includes a second concrete body  22  and a plurality of opening walls  30  in the second concrete body  22  defining an opening  36  extending through the second concrete body  22  in the vertical direction Z. In the shown embodiment, the second concrete member  20  is a precast walkway. 
     The second concrete body  22 , in the embodiment shown in  FIGS. 1 and 2 , is an elongated rectangular member extending along the lateral direction X. The second concrete body  22  has a height extending along the vertical direction Z and a width extending along the longitudinal direction Y. The second concrete body  22  has an exterior surface  24  and an interior surface  26  opposite the exterior surface  24  in the vertical direction Z. As shown in the embodiment of  FIG. 1 , the interior surface  26  has a channel  28  extending along the longitudinal direction Y and centered around the opening  36 . The channel  28  is a portion of the second concrete body  22  that has a smaller thickness in the vertical direction Z. 
     The opening walls  30  of the second concrete body  22 , as shown in the embodiment of  FIGS. 1 and 2 , form an approximately rectangular shape and include a pair of sidewalls  32  disposed opposite one another and a pair of end walls  34  disposed opposite one another and connecting the pair of sidewalls  32 . In an embodiment, as shown in  FIG. 1 , the sidewalls  32  taper in the vertical direction Z; the sidewalls  32  are spaced further apart at the exterior surface  24  than at the interior surface  26 . In various embodiments, the end walls  34  can taper in the vertical direction or can extend perpendicularly with respect to the exterior surface  24  and the interior surface  26 . The tapering of at least the sidewalls  32  of the opening walls  30  leads to a corresponding tapering of the opening  36  in the vertical direction Z. 
     As shown in  FIGS. 1 and 2 , to assemble the connection assembly, the second concrete member  20  is positioned on the end surface  14  of the first concrete member  10  in the vertical direction Z. The end surface  14  is positioned within the channel  28 . The protruding portions  18  of the reinforcing bars  16  are positioned to extend into the opening  36  and are approximately centered within the opening  36  between the opening walls  30 . As shown in  FIG. 1 , the protruding portions  18  only protrude partially through the opening  36  in the vertical direction Z and are positioned below the exterior surface  24  in the vertical direction Z. 
     In the embodiment shown in  FIGS. 1 and 2 , the first concrete member  10  and the second concrete member  20  have longitudinal extensions that are perpendicular to each other; the first concrete member  10  is elongated along the longitudinal direction Y and the second concrete member  20  is elongated along the lateral direction X. In another embodiment, the first concrete member  10  and the second concrete member  20  may have longitudinal extensions that are parallel to each other. The channel  28 , in such an embodiment, may alternatively extend along the lateral direction X to receive the end surface  14  of the first concrete member  10 . 
     In an embodiment, the interior surface  26  of the second concrete member  20 , at the channel  28 , is positioned to abut the end surface  14  of the first concrete member  10 . In another embodiment, as shown in  FIG. 1 , the connection assembly includes a cap barrier  60  disposed on the end surface  14  of the first concrete member  10 . The cap barrier  60  abuts the end surface  14  of the first concrete member  10  and the interior surface  26  of the second concrete member  20  at the channel  28 , surrounding the opening  36  at the interior surface  26 . In various embodiments, the cap barrier  60  may be a foam tape or a foam pad. 
     With the second concrete member  20  positioned on the first concrete member  10 , as shown in  FIGS. 1 and 2 , the shims  50  are positioned in the opening  36 . Each of the shims  50  is disposed along one of the sidewalls  32  and extends along an entirety of the sidewall  32  between the end walls  34 . The shims  50  are each an elongated, approximately rectangular piece sized to fit along the sidewall  32 . As shown in  FIG. 1 , in the vertical direction Z, the shims  50  are each flush with the exterior surface  24  and extend beyond the interior surface  26 , abutting the end surface  14  of the first concrete member  10 . The shims  50  are each formed of a low friction, concrete bond-breaking material such as a plastic. 
     In an embodiment, as shown in  FIG. 2 , the connection assembly includes a pair of compressible members  70  positioned in the opening  36 . Each of the compressible members  70  is disposed along one of the end walls  34  and extends along an entirety of a portion of the end walls  34  between the shims  50 . The compressible members  70  are each an elongated, approximately rectangular piece sized to fit along the end wall  34 ; the compressible members  70  each cover an entirety of the end walls  34  in the vertical direction Z. The compressible members  70 , in an embodiment, are each formed of an elastomer. 
     With the second concrete member  20  positioned on the first concrete member  10 , and the shims  50  and compressible members  70  positioned along the opening walls  30 , the cap  40  is formed in the opening  36  as shown in  FIGS. 1 and 2 . The cap  40  is a concrete material that can be formed of any mixture of cement, water, and aggregate known to those with ordinary skill in the art. The cap  40  is cast in the opening  36  after the first concrete member  10  and the second concrete member  20  are precast and are positioned in a precast state as described above and shown in  FIGS. 1 and 2 . 
     The cap  40 , as shown in  FIGS. 1 and 2 , substantially fills the opening  36  between the shims  50  and the compressible members  70  and is cast around the protruding portions  18  of the reinforcing bars  16 . The end surface  14  of the first concrete member  10  is roughened to ensure that the cap  40 , when cured, forms a strong bond with the first concrete body  12 . The cap barrier  60  limits the spread of the cap  40  while the cap  40  is curing. The cap  40 , when cured, is approximately flush with the exterior surface  24 . In the shown embodiment, due to the tapering of the sidewalls  32 , the cap  40  has a smaller width in the lateral direction X at the end surface  14  of the first concrete member  10  than at the exterior surface  24  of the second concrete member  20 . 
     The shims  50  and the compressible members  70  are disposed between the cap  40  and the second concrete member  20 , as shown in  FIGS. 1 and 2 . In another embodiment, the compressible members  70  are omitted and the space that the compressible members  70  occupy in the shown embodiment is left as an open air. In all embodiments, however, the cured cap  40  is bonded to the first concrete member  10  but is not bonded to the second concrete member  20 ; the cap  40  is spaced apart from each of the opening walls  30  of the second concrete member  20 . 
     The contact of the cap  40  with the shims  50  and the compressible member  70 , or alternatively the open spaces in place of the compressible members  70 , permits the cap  40  and the first concrete member  10  connected to the cap  40  to move with respect to the second concrete member  20  during expansion and contraction without stress or damage to the first concrete member  10 , the second concrete member  20 , or the cap  40 .