SLAB BOLSTER
A slab bolster including a longitudinally-extending spine and a plurality of legs coupled to the opposite sides of the spine and extending away from the spine. The slab bolster has a frangible portion along which the slab bolster is configured to be manually broken to allow the slab bolster to be manually separated into at least two parts.
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The present invention is directed to a bolster, and more particularly, to a slab bolster that can be used in concrete construction.
BACKGROUNDBolsters are commonly used in the construction industry to support rebar, post-tension cables, wire mesh or other reinforcements (collectively termed “reinforcing material” herein) at a desired position during a concrete pour. However, many existing bolsters must either be cut to length, or a plurality of modular sections must be connected together and built up to provide a bolster of the appropriate length. Such systems are relatively time and labor intensive in order to provide a bolster of the desired length. In addition, many existing bolsters are relatively expensive to manufacture.
SUMMARYIn one embodiment the present invention is directed to a bolster that has a frangible portion such that it can be manually broken to thereby be quickly and easily adjusted to the desired length. In addition, the bolster may in some cases be made by extrusion, providing cost savings. In particular, in one embodiment the invention is a slab bolster including a longitudinally-extending spine and a plurality of legs coupled to the opposite sides of the spine and extending away from the spine. The slab bolster has a frangible portion along which the slab bolster is configured to be manually broken to allow the slab bolster to be manually separated into at least two parts.
With reference to
The openings 16 may extend for a significant distance along the longitudinal direction/dimension (length) L (
As shown in
Each frangible portion 21 can extend around an entirety, or at least about 50% in one case, or at least about 80% in another case, of the outer surface of the spine 12 to provide or define a clean break path. In one case, the frangible portions 21 can be positioned at regular intervals along the length of the un-broken slab bolster 10, for example every six inches in one case, or every twelve inches in another case, although the spacing of the frangible portions 21 can be varied as desired. In one embodiment, each frangible portions 21 is located away from the legs 14, and in one case can be located at mid-point between adjacent legs 14 and formed only or primarily in the spine 12, although the frangible portions 21 can be located at other positions as desired.
The frangible portions 21 enable the slab bolster 10 to be easily, quickly and manually snapped to length. In particular, during use it may be desired to have the slab bolster 10 extend generally the entire length, or perhaps slightly shorter, than the length of the form in which the slab bolster 10 is placed and/or concrete slab to be formed by pouring concrete into the form. The frangible nature of the slab bolster 10 enables the slab bolster 10 to be easily snapped to length by, in one case, simply positioning the slab bolster 10 in the desired position and manually snapping/breaking at the desired predetermined location 21, thereby eliminating the need for taking measurements, cutting to length with a tool, building up to the desired length, etc.
In one embodiment, each leg 14 is generally straight and extends at a constant angle with the spine 12 relative, for example, to a height H dimension/direction (
Each leg 14 can have a length dimension oriented parallel to the longitudinal direction L, a height dimension HL oriented in a plane of each leg 14 and (in the case of straight legs 14) oriented perpendicular to the length dimension L (i.e. extending at an incline or angle in the illustrated embodiment) and a thickness dimension T oriented perpendicular to the length dimension L and the leg height dimension HL. The thickness dimension T can, in one case, be the smallest dimension of each leg 14. In addition, in one embodiment the thickness dimension T is constant along an entirety, or at least a majority, of a length of each leg 14. In other words, each leg 14 can have a uniform thickness T in a direction perpendicular to an outer surface of the leg 14.
The distal or bottom of each leg 14 may be tapered to an edge or area of reduced width 22 in the width direction W, as best shown in
In one case, the bolster 10 is shaped and configured to be nestably stackable, as shown in
The size and configuration of the legs 14/openings 16 can be varied as desired. For example, as shown in
Each bolster 10 can have a generally uniform cross-section, for the most part, such that each bolster 10 can be formed by extrusion with some additional processing steps in some cases which in some circumstances may be considered to be post-extrusion processing. Thus, the slab bolsters 10 can be made of, in one case, an extrudable material such as polymers, plastics, thermoplastics, including polycarbonate-ABS or glass filled propylene, or other materials which exhibit low water absorption, relatively high strength and relatively high impact resistance. Extrusion can be a more inexpensive production method compared to others such as injection molding, and can allow the slab bolster 10 to be extruded to any desired length for the specific desired application. In addition, rather than having to assemble multiple pieces to create a larger single piece, the present bolster 10 begins with a larger piece which can be easily snapped, at one or two locations, to provide the desired length. For example, the bolster 10 can be provided in lengths of at least ten feet, or at least about twenty feet, which are sufficient to provide a single continuous bolster for most concrete pours, although of course the length can be varied as desired.
The basic shape of each bolster 10 can be formed or extruded as a generally inverted “V” or “U,” and the openings 16 can be formed by removing materials from the side panels of the “V” or “U.” For example, in the embodiment of
The slab bolster 10 can be extruded (which includes pultruded) by passing the raw material of the slab bolster 10, under pressure (for example from a ram), through a die having the desired cross-sectional shape of the slab bolster 10. Various equipment can be used for the extrusion, for example a screw extrusion machine (single or double screw), an extrusion press, direct or indirect extrusion equipment, vertical or horizontal extrusion equipment, hydraulic or mechanical drive extrusion equipment, hydrostatic extrusion equipment, extrusion equipment which uses a puller, pultrusion equipment, or the like.
In order to utilize the slab bolsters 10 of
If desired, the lower slab bolsters 10 can be secured to the underlying deck surface 26 and/or each other. In addition, the reinforcing material 30 if desired can be secured or tied (e.g. by wire or the like) to the underlying slab bolsters 10 by wire ties or the like (not shown). The concrete can then be poured, and the slab bolsters 10 and reinforcing material 30 remain in place and remain in the poured concrete slab such that the reinforcing material 30 adds strength and durability to the finished concrete product. After pouring and curing, the poured slab can remain in place in the horizontal position or, if desired, can be released from its form and raised to a vertical or other configuration for use in tilt-up construction or the like.
If it is desired to have two or more levels of reinforcing material 30, the upper slab bolsters 10 can be utilized and stacked on the first row of reinforcing material 30, as shown in
Having described the invention in detail and by reference to the various embodiments, it should be understood that modifications and variations thereof are possible without departing from the scope of the claims of the present application.
Claims
1. A slab bolster comprising:
- a longitudinally-extending spine, wherein the spine includes at least one of a plurality of protrusions or a plurality of recesses spaced along a length thereof; and
- a plurality of legs coupled to the opposite sides of the spine and extending away from the spine, wherein the slab bolster has a frangible portion along which said slab bolster is configured to be manually broken to allow said slab bolster to be separated into at least two parts.
2. The bolster of claim 1 wherein the frangible portion is at least one of an area of weakness or reduced thickness compared to adjacent areas of the slab bolster.
3. The bolster of claim 1 wherein the slab bolster is shaped generally as an inverted “V” or an inverted “U” in end view.
4. The bolster of claim 1 wherein each leg is shaped generally as a rectangular prism.
5. (canceled)
6. The bolster of claim 1 wherein each leg has a uniform thickness in a direction perpendicular to an outer surface of each leg.
7. The bolster of claim 1 wherein each leg is generally straight and forms a constant angle with the spine relative to a height direction of the slab bolster.
8. The bolster of claim 1 wherein the spine extends generally continuously an entire length of the bolster.
9. (canceled)
10. The bolster of claim 1 further comprising a set of openings, each opening being positioned between adjacent legs, and wherein the openings extend at least about 60 percent of a length of the slab bolster.
11. The bolster of claim 1 further comprising a pair of feet, each foot being positioned at a distal end of one of the legs and extending in the longitudinal direction.
12. The bolster of claim 11 wherein each foot extends entirely between at least two adjacent legs.
13. (canceled)
14. (canceled)
15. (canceled)
16. The bolster of claim 1 wherein an inner surface of the bolster generally corresponds to an outer surface of the bolster such that the bolster is nestably stackable with other such bolsters.
17. A slab bolster comprising:
- a longitudinally-extending spine having a pair of opposite sides extending in the longitudinal direction; and
- a plurality of legs coupled to each opposite side of the spine and extending away from the spine, wherein each leg has a uniform thickness, wherein the slab bolster has a frangible portion along which said slab bolster is configured to be manually broken to allow said slab bolster to be separated into at least two parts, and wherein the slab bolster is shaped generally as an inverted “V” or an inverted “U” and lacks any structure extending entirely between a distal end of adjacent legs in a direction transverse to the spine.
18. (canceled)
19. (canceled)
20. The slab bolster of claim 17 wherein the slab bolster further includes a set of openings, each opening being positioned between adjacent legs in the longitudinal direction, and wherein the slab bolster lacks any structure extending between the distal end of adjacent legs in the direction transverse to the spine.
21. The slab bolster of claim 17 wherein each leg has a uniform thickness in a direction perpendicular to an outer surface of each leg, and wherein the spine includes at least one of plurality of protrusions or a plurality of recesses spaced along a length thereof.
22. The slab bolster of claim 17 wherein the spine includes a plurality of spaced-apart protrusions that extend generally perpendicular to an upper surface of the spine.
23. The slab bolster of claim 1 wherein an upper surface of the spine is generally flat and provides a support surface for the at least one of the plurality of protrusions or recesses.
24. The slab bolster of claim 23 wherein the spine includes a plurality of spaced-apart protrusions that extend generally perpendicular to the upper surface of the spine.
25. A slab bolster comprising:
- a longitudinally-extending spine; and
- a plurality of legs coupled to the opposite sides of the spine and extending away from the spine, wherein the slab bolster has a frangible portion along which said slab bolster is configured to be manually broken to allow said slab bolster to be separated into at least two parts, wherein each leg is curved.
26. The slab bolster of claim 25 wherein each leg is curved along its entire length from a base end of each leg, located adjacent to the spine, to a distal end thereof.
27. The slab bolster of claim 26 wherein the slab bolster has a generally inverted “U” shape in end view.
Type: Application
Filed: Oct 9, 2019
Publication Date: Apr 15, 2021
Applicant: Dayton Superior Corporation (Miamisburg, OH)
Inventors: Brandon Lee CROSS (Centerville, OH), Benjamin Bradford CLARK (Cincinnati, OH)
Application Number: 16/597,525