Rebar spacer and method
A device for supporting reinforcing bars within a form for a concrete wall having transverse form ties includes a non-metal body, configured to attach to a form tie in a fixed orientation. At least one aperture is disposed in the body, and is configured to receive an elongate reinforcing bar, so as to substantially fix the position of the reinforcing bar with respect to the form tie.
1. Field of the Invention
The present invention relates to devices for supporting and securing reinforcing bars for concrete construction. More specifically, the present invention relates to a device and method for supporting and securing rebar upon a form tie within a wall form.
2. Related Art
Reinforced concrete is one of the most common and time-tested materials in modern building construction. The placement of ductile steel reinforcing bars (“rebar”) within a concrete mass gives the resulting structure the combined benefits of concrete's high compressive strength and steel's high tensile strength and ductility. Additionally, cast-in-place concrete can be formed into almost any shape, allowing the creation of beams, columns, arches, and other shapes in almost any desired form.
It is well known that the strength and suitability of a reinforced concrete structure depends in part upon the quantity and location of the reinforcing steel. Considerable effort is expended in the design of reinforced concrete structures to determine and specify the optimum amount and location of rebar. Consequently, one persistent challenge in the subsequent construction of the structure is the proper placement of metal reinforcement within the concrete forms and keeping the reinforcement properly aligned (so as to provide adequate and consistent reinforcement) and with proper clearance from outer surfaces of the finished structure (so as to protect the reinforcement from exposure to the environment). If the steel is not placed according to the design, the resulting structure may not have the desired structural characteristics, and/or may be subject to premature degradation from environmental factors and age.
Rebar ties, chairs, and supports of various designs have been produced to help guide the placement of metal reinforcement. Unfortunately, forces created by the flow of wet concrete during placement can shift and move rebar from its intended position even when rebar fixing device are used properly, and this can easily go undetected by workers, even if they are paying close attention. Furthermore, many devices for supporting and securing rebar are inadequate for their purpose, either because of design aspects or difficulty of use. Some of these devices require significant skill and care by their user to avoid improper or inadequate rebar placement.
Unfortunately, in the construction industry, economic pressures constantly work against the effort to apply proper skill and attention to a given job. Placing additional chairs and ties within a form in order to better secure the rebar in the proper place takes time and money. Since the position of rebar within a concrete structure is generally not visible after the concrete is placed, shoddy work can easily go undetected during construction, and will generally not be noticed soon afterward except in extreme cases. Such flaws are frequently only discoverable many years after construction, when warranties have expired and there is little chance of holding the builder accountable. Furthermore, low wage, low skill laborers (as are frequently employed in the construction industry) may not possess the skill, knowledge or care needed to properly use devices that do exist to help with rebar placement, especially where such devices are cumbersome or difficult to use.
SUMMARY OF THE INVENTIONIt has been recognized that it would be desirable to have an apparatus and method for placing rebar within concrete forms that encourages proper placement of the rebar and helps secure it better.
It has also be recognized that it would be desirable to have an apparatus and method for encouraging proper rebar placement that is inexpensive and simple to use.
In accordance with one embodiment thereof, the invention provides a device for supporting reinforcing bars within a form for a concrete wall having transverse form ties. The device includes a non-metal body, configured to attach to a form tie in a fixed orientation. The body includes at least one aperture, configured to receive an elongate reinforcing bar, so as to substantially fix the position of the reinforcing bar with respect to the form tie.
In accordance with another embodiment thereof, the invention provides a concrete form system, comprising a wall form having transverse ties, and a non-metal rebar spacer, attached to a transverse tie in a fixed orientation within the wall form. The rebar spacer has at least one aperture, configured to receive an elongate reinforcing bar, and to substantially fix the position of the reinforcing bar with respect to the form tie.
In accordance with another aspect thereof, the invention provides a method for supporting horizontal reinforcement within a concrete wall form. The method includes the steps of connecting a form tie between opposing vertical walls of the wall form, attaching a non-metal rebar spacer to the form tie between the form walls in a fixed orientation, and transversely inserting an elongate reinforcing bar into at least one aperture disposed in the rebar spacer, so as to substantially fix the position of the reinforcing bar with respect to the form tie.
BRIEF DESCRIPTION OF THE DRAWINGSAdditional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention, and wherein:
A front view of one embodiment of a rebar spacer 10 in accordance with the present invention is provided in
The rebar spacer 10 generally comprises a flat body 20 of non-metal material with a variety of openings formed in it. In the embodiment of
The rebar slots or apertures 18 are generally U-shaped, and have a total width or maximum diameter that is large enough to accommodate rebar up to a certain intended size, taking into account the surface deformations of the bar. The upper opening or mouth 24 of the slots include lips 26 that protrude inwardly on each side of the opening. These lips are closer together than the minimum diameter of the bar 16 for which the particular slot is intended, so that a user is required to press the bar into the slot, after which the lips hold the bar in the slot in a press fit. This helps prevent the bar form unintentionally coming out of the slot during placement of other rebar, or during placement of the concrete in the form.
The lips 26 of the rebar apertures 18 also allow the rebar spacer 10 to support rebar 16 that is inserted from below. As shown in
The rebar slots or apertures 18 can be of a variety of sizes, so as to accommodate rebar of different sizes. For example, different rebar spacers can be configured for supporting #4 bars (i.e. ½″ diameter), #5 bars ( 5/8″ diameter), etc., for all of the different standard rebar sizes, depending upon the size to be used in a given location. Thus, where several different sizes of rebar are to be used in a given project, rebar spacers configured for each size of rebar can be provided. Alternatively, a single rebar spacer can include apertures of different sizes. For example, as shown in
The bottom region 29 of the body 20 includes two open elongate slots 30 that are configured to fit over the flat bar-type concrete form tie 14 and allow the bottom of the device to be attached thereto. The slots are disposed so as to provide a center tab region 32 and two outer tab regions 34. As shown in
A pair of deformable locking buttons 38 protrude from the plane of the body 20 upon one side of each of the outer tab regions 34. A side cross-sectional view of one of these buttons is shown in
The locking buttons 38 have an elongate shape that matches the shape of the slots 44 on the form tie, and thus helps to fix the orientation of the body 20 of the rebar spacer 10 upon the form tie 14. That is, the elongate shape resists rotation of the rebar spacer relative to the form tie, in addition to simply supporting the form tie. Additionally, because there are two locking buttons that are spaced a distance apart, this provides additional stability to the position of the rebar spacer when attached to the form tie. With the locking buttons press-fit into the slots on the form tie, the rebar spacer is thus attached to the form tie in a substantially fixed orientation.
Naturally, the size of the rebar spacer 10 will vary depending upon various factors, including the size of the wall and the size (diameter) of the rebar it is designed to support. In the embodiment shown in
Shown in
Wire-type form ties are widely used, especially in commercial construction. These ties have a generally circular cross-section. However, as seen in
As shown in the side, cross-sectional view of
Rebar spacers in a variety of other configurations can also be made in accordance with the present invention. It was noted above that a rebar spacer such as that shown in
Other configurations are also possible. For example, as shown in
Rebar spacers according to the present invention can be made of a variety of materials, including polymers such as polypropylene, polyethylene, nylon, etc. The body of the spacer can be injection molded, machined, or formed in any other manner that is suitable for the type of material. The use of non-metal materials helps prevent corrosion that can degrade a concrete structure. As is well known, corrosion of metal reinforcement within a concrete mass not only gradually destroys the reinforcing properties of the rebar, but also cracks and breaks up the concrete because of the very high expansive forces created by the corrosion process. Thus, if the rebar spacer were of a metal material, because it is in contact with the form tie and the metal rebar, corrosion of the exposed form tie end could result in corrosion of the rebar spacer and the rebar through cathodic action, and thence of any other electrically conductive material in contact therewith.
It is also desirable that the rebar spacer be somewhat flexible, though suitable materials can have a wide range of flexibility. In order to fit over a bar-type form tie, as shown in
At the same time, a large degree of flexibility is not necessarily required. For example, for an embodiment like that of
While a variety of configurations for the rebar spacer have been shown and described, it will be apparent that other configurations and combinations of elements shown can also be provided. For example, any of the various rebar spacer embodiments shown herein can include gripping feet for use with wire-type form ties, or locking buttons for attachment to bar-type form ties. Rebar apertures of different sizes and in different positions can also be provided, and any number of rebar apertures can be included on a single rebar spacer, though practical limitations of space and proper rebar spacing will likely affect the number and position of the apertures. Additionally, different combinations and arrangements of branches, etc. can also be used.
In its various embodiments, the invention provides a simple and inexpensive system and method for assisting accurate and consistent placement of rebar in a concrete form. The rebar spacer helps ensure proper alignment of rebar in spite of worker inexperience or carelessness, and helps prevent displacement of the rebar during placement of concrete. Additionally, because the device is simple, inexpensive, and easy to use, its use will not add significantly to the cost of construction.
While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.
Claims
1. A device for supporting reinforcing bars within a form for a concrete wall having transverse form ties, comprising:
- a non-metal body, configured to attach to a form tie in a fixed orientation; and
- at least one aperture, disposed in the body, configured to receive an elongate reinforcing bar, so as to substantially fix the position of the reinforcing bar with respect to the form tie.
2. A device in accordance with claim 1, wherein the body is of a polymer material.
3. A device in accordance with claim 1, wherein the at least one aperture comprises a plurality of apertures.
4. A device in accordance with claim 3, wherein the plurality of apertures have varying diameters, so that the body is able to receive and hold rebar of varying diameters.
5. A device in accordance with claim 1, wherein the at least one aperture includes a resilient lip, configured to receive and hold rebar therein in a press fit.
6. A device in accordance with claim 1, wherein the body includes at least one aperture for allowing a flow of wet concrete therethrough.
7. A device in accordance with claim 1, wherein the body includes an aperture disposed above the form tie.
8. A device in accordance with claim 1, wherein the body has a branched configuration, providing apertures for receiving reinforcing bars on more than one branch.
9. A device in accordance with claim 1, wherein the body includes an aperture disposed below the form tie.
10. A device in accordance with claim 1, wherein the body is configured to attach to a form tie selected from the group consisting of bar-type form ties and wire-type form ties.
11. A device in accordance with claim 1, wherein the at least one aperture is configured to support rebar that is oriented substantially transverse to the body.
12. A concrete form system, comprising:
- a wall form having opposing form walls;
- a transverse form tie, interconnecting the form walls; and
- a non-metal rebar spacer, attached to a form tie in a fixed orientation, the rebar spacer having at least one aperture, configured to receive an elongate reinforcing bar, and to substantially fix the position of the reinforcing bar with respect to the form tie.
13. A system in accordance with claim 12, wherein the form tie is selected from the group consisting of a bar-type form tie and a wire-type form tie.
14. A system in accordance with claim 12, wherein the rebar spacer includes a plurality of apertures.
15. A system in accordance with claim 14, wherein the plurality of apertures have varying diameters, so as to be able to receive and hold rebar of varying diameters.
16. A system in accordance with claim 12, wherein the at least one aperture includes a resilient lip, configured to receive and hold rebar therein in a press fit.
17. A system in accordance with claim 12, wherein the rebar spacer is of a polymer material.
18. A method for supporting horizontal reinforcement within a concrete wall form, comprising the steps of:
- connecting a form tie between opposing vertical walls of the wall form;
- attaching a non-metal rebar spacer to the form tie between the form walls in a fixed orientation; and
- transversely inserting an elongate reinforcing bar into at least one aperture disposed in the rebar spacer, so as to substantially fix the position of the reinforcing bar with respect to the form tie.
19. A method in accordance with claim 18, wherein the step of transversely inserting the elongate reinforcing bar into the at least one aperture comprises inserting the reinforcing bar past a resilient lip of the at least one aperture, so as to place the bar therein in a press fit.
20. A method in accordance with claim 18, wherein the step of transversely inserting the elongate reinforcing bar into the at least one aperture comprises inserting the reinforcing bar into an aperture that is disposed below the form tie.
Type: Application
Filed: Aug 24, 2005
Publication Date: Mar 1, 2007
Inventor: Matt Funk (Mendon, UT)
Application Number: 11/210,612
International Classification: E04B 1/38 (20060101); E04C 5/00 (20060101);