Rebar (typically elongated steel bars or rods) is placed in concrete structures to add tensile and shear strength (i.e., resistance to forces stretching the concrete structure apart) to its inherent compressive strength (i.e., resistance to forces pressing on it). The steel has to be placed in the proper location in the concrete structure to provide maximum resistance to compressive, tensile and shear pressures and help control cracking. In a concrete wall, horizontal reinforcement adds resistance to tensile forces, and vertical reinforcement improves resistance to shear forces. The vertical and horizontal rebars are connected to form a web or grid pattern inside a concrete form prior to pouring the concrete. It is important that the rebar maintains its location and proper spacing between the bars to ensure that the rebar is completely covered after the concrete sets.
One of the most commonly used methods to construct a rebar reinforced concrete wall is to use tie wire to secure the horizontal bar to the vertical bar. In addition, rebar beam bolsters can be used to properly space the horizontal bars from the walls of the concrete form work. After the vertical rebar are installed, the ironworker typically holds the horizontal rebar in position while wrapping a tie wire around the vertical bar to connect the two pieces together. The horizontal rebar are installed sequentially starting at the bottom and the ironworkers climb up the rebar grid as they construct it.
The reinforcement of concrete walls with an internal steel frame fabricated from rebar is well known.
The methods and rebar used to form rebar reinforcement structures are time and labor intensive as well as an immense waste of resources and materials. It would be desirable to have a system that eliminates the need for cutting slab bolsters into pieces and having to tie vertical set up rebar and manually mark out spacing. There is also a need for a method for constructing rebar grids that eliminates the need for the ironworker to manually hold the horizontal rebar in position while it is secured to the vertical rebar.
The present invention is a rebar set-up bar for construction of a rebar grid that provides reinforcement for a concrete wall or structure. The set-up bar is vertically positioned in the grid and consists of, consists essentially of, or comprises an elongated rod, preferably a metal or steel rod, most preferably a rebar, having a lower end, an upper end, a front face, a rear face and two side faces, each face substantially perpendicular to the adjoining face and a plurality of supports. The supports are attached to the elongated rod, preferably by welding, at intervals and each support includes a lower portion, an upper straight portion and an intermediate curved portion. The upper straight portion is attached to the rod, preferably by welding the support to a front face of the rod. The lower portion and the curved intermediate portion in combination form a channel with an opening facing the upper end of the elongated rod or rebar and adapted to receive a horizontal elongated rod or rebar therein.
The set-up bar can also include one or more spacers mounted at predetermined intervals along a rear face of the elongated rod. Each of the one or more spacers can include a substantially V-shaped member having two legs extending from a base. The spacer is attached to the rebar at the base. In another embodiment, each of the one or spacers comprises a substantially straight member attached to a side face of the elongated rod and extending outwardly from the elongated bar and parallel to the supports. When the rebar grid formed from the vertical set-up bars and horizontal rebars is installed in a concrete form, the spacers ensure that the rebar grid is centrally positioned between the walls of the concrete form.
The present invention also includes a rebar grid assembly that consists of, consists essentially of, or comprises a plurality of set-up bars, a plurality of horizontal rebars and a plurality of wire twists. Each set-up bar consisting of, consisting essentially of or comprising a rebar and a plurality of supports attached to the rebar, preferably by welding, at intervals. The set-up bars can also include spacers as described above. Each support includes a lower portion, an upper straight portion and an intermediate curved portion, as described above. The plurality of set-up bars are vertically oriented and aligned so that the corresponding supports of the set-up bars are at substantially equal elevations and form a plurality of rows of supports. A plurality of the horizontal rebars is positioned in the plurality of rows of supports and a plurality of wire ties secures the plurality of horizontal rebars to the plurality of supports.
The preferred embodiments of the set-up bar of the present invention, as well as other objects, features and advantages of the invention will be more clearly understood from consideration of the following description, taken in connection with the accompanying drawings.
The present invention is a set-up bar used in the construction of a rebar grid. The set-up bar includes supports for horizontal rebars and can also include spacers, which eliminates the need for rebar beam bolsters. The supports welded to the set-up bar enable ironworkers to stand on the horizontal rebar without first having to tie the horizontal rebar to the vertical rebar. This enables ironworkers to tie and fabricate walls in a more efficient manner. The set-up bar consists of, consists essentially of or comprises an elongated metal rod, preferably a rebar, with supports formed from metal rods that are formed into a “J” shape and welded on the front of the rebar at intervals. These intervals may change depending upon the design requirements of the rebar grid for each concrete wall. Additionally, spacers or bolsters may be welded to the back of the set-up bar at intervals, e.g. four foot intervals, to maintain a space between the set-up bar and the wall of the concrete form.
When rebar is used in a vertical concrete wall, a plurality of rebars is formed into a grid or lattice structure with the rebars spaced apart and arranged vertically and horizontally. At the points where the vertical rebars cross the horizontal rebars, wire ties are used to secure the two rebars together. The size (i.e., diameter and length) and number of vertical and horizontal rebars used to form the grid depends on the dimensions of the wall and the design parameters for the wall including maximum compressive, tensile and shear pressures. However, the present invention is not limited by the configuration of the rebar structure formed, the diameter and length of the rebar, the characteristics of the concrete or the material used to form the rebar.
As used herein, the term “rebar” or “reinforcing bar” refers to reinforcing steel and reinforcement steel in the form of an elongated steel bar or mesh of steel wires used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and hold the concrete in tension. The rebar used in the set-up bar can have a wide range of diameters and lengths that depend on the dimensions and the design specifications for the reinforced concrete structure that is being fabricated. In general, the heavier the load supported by a reinforced concrete structure, the larger the diameter of the rebar. The surface of the rebar is often patterned or has an irregular surface structure, such as ridges, to form a better bond with the concrete. Although rebar is preferably made from steel, any material with sufficient tensile strength can potentially be used to reinforce concrete. Therefore, although steel rebar is preferred, the present invention is not limited by the material used to form the rebar.
As used herein, the term “set-up bar” refers to the vertically positioned rebar that has one or more supports or J-hooks attached at uniformly spaced intervals and extending from the rebar in the same direction. The diameter and length of the rebar used to fabricate the set-up bar is not intended to limit the scope of the invention.
As used herein, the term “support” or “J-hook” refers to a metal structure made from rebar or a metal rod, configured in the general shape of the letter “J” and including a lower portion, an upper straight portion and an intermediate curved portion. When the vertical set-up bar is installed, the lower portion and intermediate curved portion form a channel between the lower portion and the set-up bar. The opening of the channel faces upwardly and receives the horizontal rebar.
As shown in
One skilled in the art will understand that the configuration and dimensions of the supports 14 can vary as long as they can be securely attached to the rebar 12 on upper straight portion 18 and strong enough to support a horizontal rebar 20 on the intermediate curved portion 17 and the lower portion 16. The upper straight portion 18 of the support 14 is preferably welded to the rebar 12 at a desired spacing depending on the particular specifications of the job, e.g., every 12 inches. The welded supports 14 extend away from the face of the rebar 12 in the same direction. After a plurality of vertical set-up bars 10 is installed, horizontal rebars 20 are installed in the supports 14 of the plurality of set-up bars 10. The supports 14 secure the horizontal rebar 20 so that the worker can use two free hands to affix tie wires 22 to join the horizontal rebar 20 to the vertical set-up bars 10. Before the tie wires 22 are installed, the horizontal rebar 20 can be held solely by the supports 14 as the worker climbs up the rebar grid 24 being formed.
The supports 14 also provide additional strength to the rebar grid 24 formed by the vertical set-up bars 10 and horizontal rebars 20. As workers climb the horizontal rebars 20 to add more horizontal rebars 20 to construct the grid 24 (see
As shown in
Thus, while there have been described the preferred embodiments of the present invention, those skilled in the art will realize that other embodiments can be made without departing from the spirit of the invention, and it is intended to include all such further modifications and changes as come within the true scope of the claims set forth herein.
This application claims priority from provisional application Ser. No. 62/433,328, filed on Dec. 13, 2016, which is incorporated herein in its entirety. The invention generally relates to the construction of reinforced concrete structures wherein an internal rebar frame is constructed prior to pouring the concrete. The invention more specifically relates to a rear wall set-up bar that supports the rebar during construction.
Number | Date | Country | |
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62433328 | Dec 2016 | US |