STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable.
BACKGROUND
This disclosure relates to the field of reinforcement devices for concrete structures. More specifically the present disclosure relates to stud rails used to reinforce certain types of concrete structures.
Concrete used in construction of load bearing structures may include reinforcing elements, such as those made from steel to absorb tensile load in the concrete structure. Such reinforcing may be required because concrete typically has very low tensile strength and low shear strength. One type of reinforcing structure is called a “stud rail.” A stud rail is a reinforcing element used in concrete slab structures around columns that extend from the plane of the slab. A stud rail is used as a cost-effective solution to resist “punching” shear failure at slab-column connections in elevated slabs and foundation mat slabs, as well as bursting stresses in post-tension anchorage zones. By simplifying slab reinforcement at column locations and eliminating column capitals, stirrup cages, or I—shear heads, stud rails enable efficient design and rapid construction of flat plate concrete slabs. The flat plate concrete slab format is normally faster and more cost effective, and is a preferred method for constructing condominiums, hotels, office buildings, hospitals, and other structures.
Stud rails known in the art include single headed studs which may be welded to a steel rail. Other stud rails may include double headed studs which may be welded to a steel rail. Single and double headed studs are also known to be threadedly attached to the steel rail using a threaded rod disposed at one longitudinal end of each stud.
The foregoing stud rails require welding, which may, depending on the type of structure to which the studs are attached, require certification of the welder, or may require additional machining of the rail and the studs to enable threaded coupling when threaded studs are used.
U.S. Pat. No. 8,522,504 issued to Ghali et al. discloses a device for retaining reinforcing studs in selected spacings and orientations. There is no provision for mounting the reinforcing studs to a rail disclosed in the '504 patent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 through 3 show, respectively, a side elevational view, a cross-sectional view and an end elevational view of an example embodiment of a reinforcing stud according to the present disclosure.
FIGS. 4 and 5 show isometric views of the example embodiment of the reinforcing stud shown in FIGS. 1-3.
FIG. 6 shows an end view of one of two load transfer heads on the example reinforcing stud of FIGS. 1-3.
FIG. 7 shows an end view of the other of two load transfer heads including features for affixing the reinforcing stud to a rail.
FIG. 8 shows an example threaded opening in one of the affixing features of FIG. 7.
FIG. 9 shows a plurality of reinforcing studs according to the present disclosure affixed to a rail.
FIG. 10A shows the location of a detailed view of attachment of one of the reinforcing studs to the rail.
FIG. 10B shows a more detailed view of one reinforcing stud attached to the rail of FIG. 9 and FIG. 10A.
DETAILED DESCRIPTION
FIGS. 1 through 3 show, respectively, respectively, a side elevational view, a cross-sectional view and an end elevational view of an example embodiment of a reinforcing stud 10 according to the present disclosure. The reinforcing stud 10 comprises a longitudinally elongated stud body 11 which may be cast or forged from steel or other high strength material used in concrete reinforcing devices and systems. The stud body 11 may be substantially cylindrically shaped in some embodiments.
A first load transfer head 12 may be disposed at one longitudinal end of the stud body and may be integrally formed with the stud body 11. The first load transfer head 12 may be substantially round (see FIG. 6) and may have a diameter at a load transfer face 12A larger than the diameter of the stud body 11. A diameter transition 12B between the stud body 11 and the first load transfer head 12 may be radiused or have curved portions of the cross-section of the transition 12B. The diameter transition 12B may monotonically change diameter over a length of, for example, one half the diameter of the stud body 11.
The reinforcing stud 10 may comprise a second load transfer head 14 disposed at the other longitudinal end of the stud body 11. The second load transfer head 14 may also comprise a diameter transition 14C, which may be similar in shape and/or configuration to the diameter transition 12B of the first load transfer head 12.
The second load transfer head 14 may comprise spaced apart mounting flanges 14A disposed on the end face 14D of the second load transfer head 14. The mounting flanges 14A may be substantially parallel to each other and may define between them a channel 14E for receiving a stud rail, as will be explained further with reference to FIG. 9. The mounting flanges 14A may be formed integrally with the reinforcing stud 10, with subsequent machining being limited to creating a threaded opening 14B in at least one of the mounting flanges 14A. Such opening 14B is shown in FIG. 1. The mounting flanges 14A may define a substantially rectangular cross-section as shown in FIGS. 2 and 3, or may on their exterior conform to the shape of the second load transfer head 14. In the present embodiment, the interior wall 14E of each mounting flange 14A may be substantially perpendicular to the end face 14D for receiving a rectangular cross section stud rail (see FIG. 9). In other embodiments, one or both interior walls 14E may be other than perpendicular to the end face 14D so as to receive therein a stud rail that is other than rectangular cross section.
FIGS. 4 and 5 show isometric views of the example embodiment of a reinforcing stud 10 as explained with reference to FIGS. 1-3. The end face 14D of the second load transfer head 14 is clearly visible in FIG. 4 as having the described channel 14E defined between the mounting flanges 14A. FIG. 5 clearly shows the flat load transfer surface 12A of the first load transfer head 12.
An end view of the first load transfer head 12 is shown in FIG. 6.
An end view of the second load transfer head 14 is shown in FIG. 7, wherein the mounting flanges 14A may be observed.
FIG. 8 shows an example of the threaded opening 14B that may be formed in at least one of the two mounting flanges 14A. The threaded opening 14B may receive therein a set screw as will be explained with reference to FIG. 10 so as to lock the reinforcing stud in place on a rail. The threaded opening 14B may be machined, or may be formed integrally with and at the time the mounting flanges 14A are formed.
FIG. 9 shows a plurality of reinforcing studs 10 according to the present disclosure coupled to a stud rail 16 at spaced apart locations along the stud rail 16. The distance between adjacent reinforcing studs may be chosen to suit the particular concrete reinforcement requirements of a cast concrete structure. The example embodiment shown in FIG. 9 comprises reinforcing studs 10 spaced apart by equal distances between adjacent reinforcing studs. In some embodiments the reinforcing studs 10 may be unequally spaced.
FIG. 10A shows an isometric view of an example embodiment of a stud rail, more particularly pointing out the location of a detailed view of attachment of one of the reinforcing studs to the rail shown in FIG. 10B.
FIG. 10B shows an isometric view of the rail 16 disposed on the second load transfer head 14. A set screw 18, for example a socket head set screw as shown in FIG. 10B may be disposed in the one or each threaded opening (14B in FIG. 8) such that when threaded inwardly against the rail 16, the rail 16 becomes locked to the second load transfer head 14.
The position of and the number of load transfer studs according to the present disclosure that may be coupled to the rail 16 may be predetermined, may be selected during assembly of the concrete reinforcing structure and/or may be changed during or after assembly of the concrete reinforcing structure without the need for any cutting, welding or other similar reworking of the rail structure.
Although only a few examples have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the examples. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.
Patent Application
20180223532
