The present invention relates in general to a support frame with dowels for use as reinforcement for a concrete structure. More specifically, but not exclusively, the invention relates to a road basket for poured concrete in roadway construction and other slap type construction.
Concrete and other masonry or cementitious materials have compressive strength but substantially low tensile strength. Thus, when using concrete as a structural member, for example, in a building, road, bridge, pipe, pier, culvert, or the like, it is conventional to incorporate reinforcing members to impart the necessary tensile strength. Historically, the reinforcing members are steel or other metal reinforcing rods or bars, i.e., “rebar.” Such reinforcing members may be placed under tension to form pre-stressed or positioned concrete structures.
Currently, reinforced concrete employs a system of dowels which is supported by a metallic support frame to elevate the dowels to a desired height within the poured concrete structure. For example, when slabs are poured for concrete roadways, a rebar lattice comprising a system of dowels and support frames are generally used to provide additional strength and support. The rebar lattice forms what is typically known as a road basket that allows the concrete to be poured over the dowels and its supporting frame. It is well-known that concrete has a high compressive strength, but a low tensile and shear strength. Furthermore, concrete expands and contracts due to changes in temperature. Previously, dowels have been incorporated into concrete structures to transfer shear loads at joints and allow the concrete blocks or slabs to expand in a desired direction. By controlling the direction of expansion of the slabs, engineers can minimize the likelihood that highways and other surfaces will become uneven.
Steel dowels, such as rebar, are typically used in current construction methods as it was considered a cost effective way to provide the necessary strength required by the application. However, steel and other metals are susceptible to oxidation and corrosion. Oxidation and/or corrosion of the metal dowels negates the benefits provided by including the dowel and support frame in the poured concrete and can result in structural damage.
Such structural damage has become a major problem in a wide variety of geographical areas. For example, bridges, roadways, and other concrete building infrastructures in northern United States' cities are constantly in need of repair because of the accelerated oxidation and/or corrosion resulting from the salting of roadways throughout the winter or exposure to higher salt concentrations in the air near the ocean. For example, the bridges leading to the Keys in Florida which are exposed to sea air are continuously being rebuilt because of the short lifespan of the concrete. Thus, it is readily apparent that there is a critical need for a solution to the corrosion problem.
In attempting to solve this problem others have suggested using composite materials such as fiberglass dowels, fiber composite dowels, and/or fiber reinforced plastic (“FRP”) dowels to replace the steel dowels. While composite dowels have been used to replace the steel dowels in the prior art, such incorporation also presents problems. The most significant problem being that composite materials cannot be welded to a metallic support frame. Thus, the prior art has developed numerous examples of securing apparatuses. For example, a series of clips that may be used to secure the composite or fiberglass dowel to its underlying metallic support frame. This requires extensive labor to assemble all of the components and ensure that the clips remain attached. Because the clips are not permanently secured, they may also cause problems during installation and pouring of concrete if things fall apart.
Thus, there continues to be a need for a frame that provides an efficient means of attaching a synthetic or non-metallic reinforcing member or dowel to a support frame.
Therefore, it is a primary object, feature, and/or advantage of the invention to improve on and/or overcome the deficiencies in the art.
It is another object, feature, and/or advantage of the invention to provide a means of attaching a non-metallic dowel to a support frame.
It is yet another object, feature, and/or advantage of the invention to provide a method of attaching a dowel to a support frame.
It is a further object, feature, and/or advantage of the invention to provide a road basket that includes a support frame and non-metallic dowel for use with poured concrete.
It is still a further object, feature, and/or advantage of the invention to provide a road basket support frame that includes opposing coils for attaching a dowel.
A further object, feature, and/or advantage of the present invention is to provide a structural rebar which is resistant to corrosion and thereby reduces the cracking and crumbling of the cementitious material.
These and/or other objects, features, and/or advantages of the present invention will be apparent to those skilled in the art. The present invention is not to be limited to or by these objects, features, and advantages. No single aspect need provide each and every object, feature, or advantage.
One aspect of the present invention provides an improved road basket including a non-metallic dowel including opposing first and second ends. The first end configured to be secured to a first support frame by inserting the first end of the dowel through a first coil member of the first support frame. The second end of the dowel configured to be secured to a second support frame by inserting the second end of the dowel through a second coil member of the second support frame. The first and second support frames may be oriented to be generally parallel to one another. Furthermore, the first coil and second coil are configured to be wrapped around the first and second ends of the dowel, respectively. The support frames may be welded, including the coil members, and the ends of the dowel may be slidably inserted or pressed into the coils. The support frames may include multiple coils oriented along a plane or axis, each coil configured for securing an end of a dowel.
The first support frame and the second support frame may be constructed of a single piece or several pieces welded together. The dowel is preferably made from fiberglass or glass fiber reinforced polymer or fiber reinforced plastic (“FRP”). Thus, the support frames and dowels should provide the ability to flex, while not compromising strength or durability.
During manufacturing, the dowels are protruded, depending on their construction, and cut to a desired length. Once cut to a desired length, both ends of each dowel are ready to be secured to their respective support frame leg via a coil. A coil is formed at one end of the support frame leg by either wrapping the end of the support frame leg around one end of the dowel, or optionally loading the dowel and support frame members into a hydraulic powered weld fixture that will press the coils on the dowel ends and then weld the base frame member and intermediate frame member onto the support frame leg. Preferably, several dowels and support frame members may be placed in the weld fixture simultaneously such that when the frame legs, base frame members, and intermediate members are welded together and attached to the dowels via the coils, and the road basket is formed. Optionally, the frame members may be welded together separately, wherein the dowels are added subsequently.
Once formed, the complete road basket is transported to a work site. At the work site, the users may cut the road basket to a desired length using readily available cutting tools, including cutting torches or saws generally used to cut metal. If necessary, the road basket may be secured in a desired location on the work site by securing an anchor to the first support frame. These anchors may be U-shaped or any other shape of anchor which is capable of holding the road basket in place.
Different aspects may meet different objects of the invention. Other objectives and advantages of this invention will be more apparent in the following detailed description taken in conjunction with the figures. The present invention is not to be limited by or to these objects or aspects.
Various embodiments of the invention will be described in detail with reference to the drawings, wherein like reference numerals represent like parts throughout the several views. Reference to various embodiments does not limit the scope of the invention. Figures represented herein are not limitations to the various embodiments according to the invention and are presented for exemplary illustration of the invention.
An apparatus and system for securing a reinforcing dowel as part of a road basket for use with concrete and other masonry or cementitious materials is disclosed. The road basket may be used to reinforce poured concrete slabs, such as paved roads and bridges. For example, the road basket may be placed within the area where a concrete slab is to be poured for a roadway. The road basket may be configured to secure a dowel at a preferred location, such as height or depth, to provide improved structural properties for the concrete structure.
As shown in
Also shown in
During manufacturing, the dowels 12 are extruded or protruded, depending on their construction, and cut to a desired length. Preferably, an FRP pultrusion machine is used to manufacture the dowels 12. Once cut to a desired length, the first support frame coil 28 may be secured around the dowel first end 16 by wrapping an end of the first support frame leg 26 around the dowel first end 16. The first coil is preferably a first spring coil, as shown in
Thus, to assemble the road basket 10, the dowel first end 16 may be slidably inserted into the first support frame coil 28, and the dowel second end 18 may be slidably inserted into the second support frame coil 32 with applied pressure. This allows increased flexibility and means of adjustment as the dowel 12 remains snug and secure inside the coils 28 and 32, while the frame 14 maintains the ability to flex and adjust with applied force. In both manufacturing processes, the friction and tight-fit of the coils 28 and 32 around the dowel ends 16 and 18 secures the dowel 12 to the frame 14 without any glue or welding required. This saves considerably on time and labor costs. Furthermore, slight deformations of the dowel may occur while manufacturing the dowels. These deformations serve to reinforce the hold of the coils 28 and 32 on the ends of the dowel 16 and 18 at the connection point 15. Alternatively, the coil 28 and 32 may be heat treated to provide the appropriate ration of flexibility to rigidity to allow insertion of the dowel 12 into the coil 28. Furthermore, the coil 28 may be heated to allow for expansion of the interior diameter of the coil 28 prior to inserting the dowel 12. The expansion of the coil 28 from the heat will allow for the dowel to be inserted with less force, and as the coil cools it will retract, securing the dowel in place via friction force or pressure.
A close-up view of the connection point 15 between the dowel first end 16 and the first support frame coil 28 is shown in
As illustrated in
Once formed, the complete road basket 10 is transported to a work site. At the work site, the users may cut the road basket 10 to a desired length using readily available cutting tools, including metal saws and cutting torches. If necessary, the road basket 10 may be secured in a desired location on the work site by securing an anchor to the frame 14. These anchors may be U-shaped or any other shape of anchor which is capable of holding the road basket in place.
The road basket of the present invention and method of manufacture are universally applicable to concrete structures of all shapes and sizes, makes, models, and manufacturers. Furthermore, while intended for large concrete structures such as bridges, buildings, and roads, the road basket of the present invention may be used for concrete structures in all manner of uses, large and small. Although the invention has been illustrated and described with respect to aspects described above, it should be understood by those skilled in the art that the foregoing and various other changes, modifications, omissions and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific aspects set forth above but to include all possible embodiments which can encompass equivalents thereof with respect to the features set out in the claims and within the full intended scope of the invention.
The present invention claims priority to co-pending PCT application U.S. Ser. No. 15/59,750 filed on Nov. 9, 2015 and is a bypass continuation thereof.
Number | Date | Country | |
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Parent | PCT/US15/59750 | Nov 2015 | US |
Child | 15726101 | US |