Patent Publication Number: US-2018030669-A1

Title: Road basket

Description:
PRIORITY CLAIM 
     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. 
    
    
     FIELD OF THE INVENTION 
     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. 
     BACKGROUND OF THE INVENTION 
     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&#39; 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. 
     BRIEF SUMMARY OF THE INVENTION 
     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. 
    
    
     
       DESCRIPTION OF FIGURES 
         FIG. 1  is a perspective view of a road basket. 
         FIG. 1A  is a perspective view of a road basket leg and coil. 
         FIG. 1B  is a front view of the road basket leg and coil of  FIG. 1A . 
         FIG. 2  is a front view of the road basket of  FIG. 1 . 
         FIG. 3  is a top view of the road basket of  FIG. 1 . 
         FIG. 4  is a section view of the road basket frame of  FIG. 3 . 
         FIG. 5  is a side view of the road basket of  FIG. 1 . 
         FIG. 5A  is a section view of the road basket frame of  FIG. 5 . 
     
    
    
     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. 
     DETAILED DESCRIPTION 
     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. 
       FIG. 1  illustrates a perspective view of an example embodiment of a road basket  10 . The road basket  10  may include a plurality of dowels  12 , preferably composed of a non-metallic material. However, the dowels  12  may be made from any desired non-corrosive material that provide the appropriate structural properties. For example, the dowels  12  may be composed from fiberglass, a glass fiber reinforced polymer, or a fiber reinforced plastic (FRP). These materials provide a desired amount of flexibility, while also providing additional tensile strength. The matrix resin for the FRP dowels may be selected among thermosetting resin, such as epoxy resin, unsaturated polyester, phenol resin or so forth and thermoplastic resin, such as nylon, polyester or so forth. On the other hand, the reinforcing fiber may be selected from among inorganic fibers, such as carbon fiber, glass fiber or so forth, or organic fibers, such as aramid fiber or so forth. However, any suitable materials for forming FRP can be used. 
     As shown in  FIG. 1 , the non-metallic dowels  12  are generally held in an elevated position by a frame  14 . The frame  14  may be configured to secure multiple dowels  12  parallel to one another. The dowels may also be oriented parallel to the ground. However, the frame  14  may be configured to orient the dowels  12  in any position relative to the other dowels  12 , or relative to the structure or environment. For example, one side of the support frame  22  may include longer support legs  26 , relative to the opposing support frame  24  which may include shorter support legs  30  relative to support legs  26 . This would create a sloped effect for the dowels  12  relative to the ground that the frame  14  is resting on. Having the support legs  26  and  30  being the same length/height would create a flat planar surface which would simplify installation of the dowels  12  in a slip form paving process. Preferably, the frame  14  is manufactured using a hydraulic powered weld fixture. The frame  14  may be constructed from a high density steel that provides flexibility without compromising strength or durability. For example, a spring steel may be used to construct the frame to provide the necessary tension and/or compressive forces on the interior of the coil  28  and  32 . The combination of these selected materials, a composite dowel  12  with a metallic frame  14  (i.e., steel, iron, etc.) creates flexibility and provides a road basket  10  which is lightweight and easy to handle. 
     Also shown in  FIGS. 1-3 , the dowel  12  includes a dowel first end  16 , a dowel second end  18  and an intermediate portion  20 . A first support frame  22  and a second support frame  24 , oriented in parallel to one another, are also shown. The first support frame  22  generally includes a first support frame leg  26  and a first support frame coil  28 . The first support frame coil  28  may be integral with the first support frame leg  26 . A close-up view of a representative embodiment of the first support frame leg  26  with support frame coil  28  is shown in  FIGS. 1A and 1B . As shown in  FIGS. 1A and 1B , the support frame leg  26  may be set at an angle away from the support frame coil  28 . This is also represented in  FIG. 2 . One potential advantage of angling the legs  26  and  30  away from the dowel  12 , as shown in  FIG. 2 , is that it can provide better support and prevent the road basket  10  from being dislodged or tipped when the concrete is poured. Similarly, the second support frame  24  includes a second support frame leg  30  and a second support frame coil  32 . The support frame legs  26  and  30  may be connected to additional support frame legs by an intermediate frame member  48  and/or base frame member  46 . As few or as many support frame legs  26  and  30  may be connected as are required for a particular project or application. For example, pouring a slab of concrete for a driveway may require a length of road basket that includes twenty ( 20 ) sets of legs  26  and  30 , whereas a roadway may require thousands of sets of support frame legs  26  and  30  to be connected by the frame member  46  and/or  48 . 
     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  FIG. 1B , with a first coil first end  29  that terminates or ends free from further contact with the rest of the support frame  14  or legs  26 . Similarly, the second coil is preferably structured in the same manner as shown in  FIG. 1B , with a second coil first end that terminates or ends free from further contact with the rest of the support frame  14  or legs  26 . The second support frame coil  32  is secured around the dowel second end  18  in the same manner. Alternatively, the coil  28  may also be pre-formed as part of the support frame leg  26  manufacturing process and the dowel first end  16  may later be pressed or inserted into the coil  28  (i.e., via a hydraulic powered weld fixture). The diameter of the first support frame coil  28  may be smaller than the diameter of the dowel first end  16  to increase friction and pressure between the coil  28  and dowel  12 . Increased friction and/or pressure between the coil  28  and the dowel  12  may create a more secure attachment. Similarly, the second support frame coil  32  is formed in an end of the second support frame leg  30  before the dowel second end  18  is pressed or inserted into the second support frame coil  32 . 
     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  FIG. 4 . As further illustrated in  FIG. 4 , when the coiling occurs over the end portion  16  of the dowel  12 , an interface bond is formed at the connection point  15  between the outer surface of the dowel  12  and the inner surface of the first support frame coil  28  through friction. This bond at the connection point  15  can be broken by the forces of the expansion and contraction of the concrete, which is the design intent, which corresponds to current practice of welding every other end of steel dowel to metallic frame. In this manner, the road basket  10  of the present invention maintains the desired qualities of a steel frame with the additional benefits provided by a composite dowel including non-corrosion, easy installation and efficient manufacturing. Moreover, the present invention provides the added benefit of flexibility and self-adjustment as the dowels maintain the ability to adjust inside the coils after the interface bond is broken. 
     As illustrated in  FIGS. 1, 3, and 5 , the frame  14  may include multiple frame legs  26  and  30  and coils  28  and  32 . For example, the first support frame leg  26  and first support frame coil  28  are shown next to a first support frame second leg  42  and first support frame second coil  44 . The first support frame second coil  44  is secured to a second dowel  34  having a second dowel first end  36 , a second dowel second end  38  and a second dowel intermediate portion  40 . The first support frame second coil  44  is secured to the second dowel first end  36  as discussed above relative to the first support frame coil  28  and the first dowel first end  16 . This process can be repeated to include as many dowels as desired. As also shown in  FIGS. 1 and 3 , the first and second support frames  22  and  24  may each include a base frame member  46  and an intermediate frame member  48  welded to their respective first and second support frame legs  26  and  30 . A close-up view of the first support frame leg  26  attached to the base frame member  46  and intermediate frame member  48  is illustrated in  FIG. 5A . The base frame member  46  provides a bottom surface for the frame  14  stabilizing the road basket  10  on the ground or installation surface. The intermediate frame member  48  provides further stability for the road basket  10 . The first and second support frames  22  and  24  may be welded separately to base frame members  46  and intermediate frame members  48  after the dowel ends  16  and  18  are pressed or inserted into their respective support frame coils  28  and  32 . Optionally, all of the components may be loaded into a hydraulic powered weld fixture that presses the dowel ends  16  and  18  into the support frame coils  28  and  32  while simultaneously welding the base frame members  46  and intermediate frame members  48  onto the first and second support frames  22  and  24 . Preferably, many dowels may be placed in the hydraulic powered weld fixture concurrently and the frame members may be welded simultaneously such that when the frames and dowel structures are removed from the fixture, the road basket  10  is formed. 
     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.