Abstract:
A load-transfer device for a structure comprises a top member, a bottom member and at least one web member. The top member comprises a bottom surface adapted to receive a top surface of the structure. The bottom member comprises a top surface adapted to receive a bottom surface of the structure. Each web member comprises at least one aperture extending through the web member between the bottom surface of the top member and the top surface of the bottom member. Each aperture is capable of receiving a bolt member that is capable of fastening at least one of the top member, the bottom member or combinations thereof to the web member.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    The present patent application claims priority to U.S. Provisional Patent Application Ser. No. 61/056,417, entitled “Connector For Reinforcing Concrete Structure,” invented by John. L. Lytton, filed May 27, 2008, and the disclosure of which is incorporated by reference herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0002]    The subject matter disclosed herein is illustrated by way of example and not by limitation in the accompanying figures in which like reference numerals indicate similar elements and in which: 
           [0003]      FIG. 1  depicts a cross-sectional view of an exemplary parking deck formed from concrete structures generally having a double-T-shaped cross-section; 
           [0004]      FIG. 2A  depicts a widthwise cross-sectional view of an exemplary embodiment of a load-transfer device according to the subject matter disclosed herein; 
           [0005]      FIG. 2B  depicts a lengthwise cross-section view of an exemplary embodiment of a load-transfer device according to the subject matter disclosed herein; and 
           [0006]      FIG. 3  depicts a lengthwise cross-sectional view of an exemplary embodiment of a load-transfer device according to the subject matter disclosed herein in which a plurality of web members span between a corresponding pair of a top plate and a bottom plate. 
       
    
    
     DETAILED DESCRIPTION 
       [0007]    It should be understood that the word “exemplary” as used herein means “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not to be construed as necessarily preferred or advantageous over other embodiments. 
         [0008]    The subject matter disclosed herein relates to a concrete-structure load-transfer device (or connector for reinforcing a concrete structure) as depicted by the exemplary embodiments shown in  FIGS. 1-3 . 
         [0009]      FIG. 1  depicts a cross-sectional view of an exemplary parking deck  100  formed from concrete structures  101  generally having a double-T-shaped cross-section. It should be understood that  FIG. 1  only depicts a portion of each of two adjacent double-T concrete structures  101 . Steel angles (not shown) are cast into the edge at several places along the edge of a double-T-shaped concrete structure  101 . A piece of rebar is welded between adjacent steel angles on adjacent double-T concrete structures for transferring loads between the two double-T structures. The welded rebar and the steel angles are subject to rust and corrosion, thereby making the load-transferring aspect of the welded rebar and steel angle susceptible to failure. 
         [0010]    A load-transfer device  200 , formed from two plates that are fastened together through a web connection mechanism, such that the cross-sectional shape of the load-transfer device is similar to an I-beam, functions to bridge between adjacent double-T-shaped concrete structures  101  and, in so doing, provides structural support between adjacent double-T-shaped concrete structures  101 , and the overall parking structure  100 . A number of load-transfer devices  200  are placed along a joint between two adjacent double-T structures  101 , such as in an expansion joint, to sufficiently transfer the loads between the double-T structures for the stresses and loads that double-T structures  101  are expected to experience. Load-transfer device  200  provides an advantage in that installation of load-transfer device  200  does not disturb the construction that is already in place because the construction that is in place does not need to be broken up in order to install a load-transfer device  200 . Moreover, installation of a number of load-transfer devices  200  can be done in a short time period, such as overnight. 
         [0011]      FIG. 2A  depicts a widthwise cross-sectional view of an exemplary embodiment of a load-transfer device  200  in accordance with the subject matter disclosed herein.  FIG. 2B  depicts a lengthwise cross-section view of the exemplary embodiment of load-transfer device  200  in accordance with the subject matter disclosed herein. 
         [0012]    As depicted in  FIGS. 2A and 2B , the exemplary embodiment of a load-transfer device  200  comprises a top plate or member  201 , a bottom plate or member  202  and a web member  203 . For one exemplary embodiment, the top plate  201  and the bottom plate  202  are about 8″ wide by about 16″ long and about ⅜″ thick. Other plate sizes can be selected based on, but not limited to, such factors as the thicknesses of the double-T-shaped concrete structures for which loads are to be transferred and the stresses that the load-transfer devices are expected to experience. Web member  203  is fastened to the underside of top plate  201  in a well-known manner, for example, by welding at  204 . In an alternative exemplary embodiment, web member  203  and top plate  201  could be formed integrally, such as by forging. As yet another exemplary alternative, the web member could be separate from the top and bottom plates, such that the load-transfer device is fastened together by the bolts. 
         [0013]    One exemplary embodiment of web member  203  comprises three (3) apertures  205 . Alternatively, other exemplary embodiments provide a web member comprising a different number than three apertures  205 . Top plate  201  and bottom plate  202  respectively have apertures  207  and  208  that correspond to the apertures  205  of web member  203 . A flathead bolt  206  extends through each corresponding set of apertures  207 ,  205  and  208  through bottom plate  202 . Assembled, each bolt  206  extends through apertures  205  of web member  203 , through bottom plate  202  and is fastened by, for example, a washer  209 , a nut  210  and welding. Other exemplary embodiments fasten bottom plate  202  to the bolts using well-known techniques, such as by welding. In one alternative exemplary embodiment, apertures  207  are formed as counter-sunk blind apertures so that washer  209  and nut  210  are attached to a bolt  206  adjacent to top plate  201  without projecting substantially above top plate  201 . 
         [0014]    In another alternative exemplary embodiment, web member  203  is welded to or integrally formed with top plate  201 , and studs are formed on web member  203  on the edge adjacent to bottom plate  202  that pass through corresponding apertures on bottom plate  202 . Bottom plate  202  is fastened to web member  203  using washers and nuts tightened onto the studs. 
         [0015]    A neoprene pad member  211 , of which only one neoprene pad is shown in  FIG. 2A , can be used between bottom plate  202  and the underside of a double-T-shaped concrete structure (not shown in  FIGS. 2A and 2B ) to better conform load-transfer device  200  to a double-T concrete structure. It should be understood that pad member  211  could be formed from a suitable material other than neoprene. 
         [0016]    Load-transfer device  200  can be made from materials that are suitable for experiencing the loads and stresses that are expected to be experienced by load-transfer device  200 , such as, but not limited to, steel. In one exemplary embodiment, the load-transfer device is formed from stainless steel. 
         [0017]    It should be understood that the shapes of the top and bottom plates can be different from the rectangular exemplary embodiment shown. Further, it should be understood that the top and bottom plates need not be the same size and/or the same shape. As another exemplary alternative embodiment, the web member could be fastened in a well-known manner to the topside of the bottom plate, such as by welding. In an alternative exemplary embodiment, the web member and the bottom plate could be formed integrally, such as by forging. 
         [0018]    As still another alternative exemplary embodiment,  FIG. 3  depicts a lengthwise cross-sectional view of an exemplary embodiment of a load-transfer device according to the subject matter disclosed herein in which a plurality of web members  303  span between a corresponding pair of a top plate  301  and a bottom plate  302 . In particular,  FIG. 3  depicts three web member  303  spanning between a top plate  301  and a bottom plate  302 . Web member  303  comprises at least one aperture  305  that extends between top plate  301  and bottom plate  302 . It should be understood that any number of web members  303  could span between top plate  301  and bottom plate  302 . 
         [0019]    A flathead bolt  306  extends through each aperture  305  to and through bottom plate  302 . Top plate  301  and bottom plate  302  respectively have apertures  307  and  308  that correspond to the apertures  305  of web members  303 . Assembled, each bolt  306  extends through apertures  305  of the web members, through bottom plate  302  and is fastened by, for example, a washer  309 , a nut  310  and welding. It should be understood that each web member  303  could have any number of apertures  305 . Other exemplary embodiments fasten bottom plate  302  to the bolts using well-known techniques, such as by welding. 
         [0020]    As a further alternative exemplary embodiment, a single web member could span between at least two sets of corresponding pairs of top and bottom plates to form a load-transfer device. 
         [0021]    Another exemplary embodiment comprises one or more reinforcing members, such as reinforcing bar (commonly known as “rebar), a mesh and/or a grid of material could be positioned around the load-transfer device disclosed herein and extending into the adjacent double-T structures for further structural integrity between two adjacent double-T structures. 
         [0022]    Additionally, while the exemplary embodiment depicted in  FIGS. 1 ,  2 A and  2 B is shown as having a non-beveled top plate, it should be understood that the top plate could be beveled and/or sloped at the outer edges. 
         [0023]    One exemplary embodiment provides that the load-transfer device of the subject matter disclosed herein is placed directly on top of the formed surface of, for example, a parking deck floor. Another exemplary embodiment provides that the load-transfer device of the subject matter disclosed herein is placed within a shallow hole formed in the surface of two adjacent double-T structures so that the top surface of the top plate is substantially level with the top surfaces of the two adjacent double-T structures. Yet another exemplary embodiment provides that the load-transfer device of the subject matter disclosed herein and one or more reinforcing members are placed within a shallow hole formed in the surface of two adjacent double-T structures so that the top surface of the top plate is substantially level with the top surfaces of the two adjacent double-T structures. The hole is then resurfaced in a well-known manner with a suitable fill material so that the suitable fill material and the top plate are substantially level with the top surfaces of the two adjacent double-T structures. 
         [0024]    It should be understood that the load-transfer device disclosed herein is not limited in use with double-T concrete structures, but can be used for reinforcing other suitable structures. 
         [0025]    Although the foregoing disclosed subject matter has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced that are within the scope of the disclosed subject matter. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the subject matter disclosed herein is not to be limited to the details given herein, but may be modified within the scope and equivalents of the disclosed subject matter.