US20090293397A1

US20090293397A1 - Load-Transfer Device For Reinforcing Concrete Structures

Info

Publication number: US20090293397A1
Application number: US12/473,209
Authority: US
Inventors: John L. Lytton
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-05-27
Filing date: 2009-05-27
Publication date: 2009-12-03

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

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

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:

FIG. 1 depicts a cross-sectional view of an exemplary parking deck formed from concrete structures generally having a double-T-shaped cross-section;

FIG. 2A depicts a widthwise cross-sectional view of an exemplary embodiment of a load-transfer device according to the subject matter disclosed herein;

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

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

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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Additionally, while the exemplary embodiment depicted in FIGS. 1, 2A and 2B 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.
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.
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.
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.

Claims

1. A load-transfer device for a structure, comprising

a top member comprising a bottom surface adapted to receive a top surface of the structure;

a bottom member comprising a top surface adapted to receive a bottom surface of the structure; and

at least one web member disposed between the bottom surface of the top member and the top surface of the bottom member, each web member comprising 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 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.

2. The load-transfer device according to claim 1, wherein at least one web member is welded to the top member.

3. The load-transfer device according to claim 1, wherein at least one web member is integrally forged with the top member.

4. The load-transfer device according to claim 1, wherein at least one web member is welded to the bottom member.

5. The load-transfer device according to claim 1, wherein at least one web member is integrally forged with the bottom member.

6. The load-transfer device according to claim 1, wherein the top member, the bottom member and the web member are formed from stainless steel.

7. The load-transfer device according to claim 1, further comprising a bolt member received in each aperture extending through the web member between the bottom surface of the top member and the top surface of the bottom member.

8. The load-transfer device according to claim 1, further comprising at least one pad member disposed between the top surface of the bottom member and the bottom surface of the structure.

9. The load-transfer device according to claim 1, wherein the structure comprises two adjacent double-T-shaped concrete structures.

10. The load-transfer device according to claim 9, wherein the structure comprises a parking deck structure.

11. The load-transfer device according to claim 10, wherein the load-transfer device is disposed in an expansion joint of the parking deck structure.

12. A load-transfer device for a structure, comprising

at least one web member disposed between the bottom surface of the top member and the top surface of the bottom member, each web member comprising at least one stud member capable of extending through an aperture extending through at least one of the top member and the bottom member, each stud member 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.