Upgrading substandard to standard concrete barriers using lightweight metal-GFRP assembly

Abstract

Apparatus and methods of upgrading substandard concrete barriers to a standard barrier height are provided. One or more metal frame box members can be secured to an upper portion of a substandard barrier via one or more glass fiber reinforced plastic sheets to create a standard barrier that is geometrically adequate to withstand vehicle impacts and prevent vehicle roll over.

Description

UPGRADING SUBSTANDARD TO STANDARD CONCRETE BARRIERS USINGLIGHTWEIGHT METAL-GFRP ASSEMBLYRELATED APPLICATION

[0001] This Application claims the benefit of U.S. Provisional Patent Application No. 63 / 593,714, filed October 27, 2023, which is incorporated by reference herein in its entirety.BACKGROUND OF THE INVENTIONField of the Invention

[0002] Embodiments according to certain aspects of the present invention are directed to apparatus and methods of upgrading substandard concrete barriers to a standard barrier height needed for geometrical adequacy.Description of the Prior Art

[0003] Bridge piers are subject to extreme loading events represented by collisions with heavy vehicles. Many vehicle-pier crash events have been reported with catastrophic consequences. Between 1952-2000, out of 617 reported bridge collapses 31 were caused by vehicle impacts with piers. The American Association of State Highway and Transportation Officials (AASHTO) introduced the Vehicular Collision Force (VCF) as a limit state to design bridge piers for the first time in 1998: an Equivalent Static Force (ESF) of 1780 kN (400 kips) acting at 1.2 m (4 ft) above the ground level. Currently, the AASHTO prescribes bridge piers to resist 2670 kN (600 kips) or to provide protection for the pier through use of a standard (42 inch) barrier. However, the likelihood of identifying bridges that neither have piers designed to resist the VCF nor a TL-5 barrier installed is quite high.

[0004] It is widely accepted in the literature and through the Manual for Assessing Safety Hardware (MASH) that barriers used to protect bridge piers from vehiclecollision impact by redirecting its direction needs to be 42 inches in height. These are called standard barriers. At some point in the past, the AASHTO considered 32-inch barriers acceptable. However, more research and AASHTO specification revisions resulted in considering this and some other types of barriers to be substandard (unacceptable). In a recent study, it was shown that substandard barriers of 32 inches height, available in abundance on the highway inventory, has the strength capacity to resist TL5 crashes but suffer from the geometrical deficiency of the substandard height causing impact trucks to roll over these barriers.SUMMARY OF THE INVENTION

[0005] To efficiently and economically solve this problem, these substandard barriers may be repaired using a lightweight, easy to install and durable system to give them the standard height advantage. This can be accomplished by manufacturing lightweight small metal frame boxes to place on top of the substandard barriers while applying glass fiber reinforced polymer (GFRP) sheets to bond these metal boxes completely to the barrier to act as one unit. This system permits the geometrical upgrade of substandard barriers that are structurally strong enough to prevent the roll over issues.

[0006] According to one embodiment of the present invention there is provided a method of upgrading a substandard roadway barrier to a standard roadway barrier. One or more box frame members are installed on an upper margin of the substandard roadway barrier. The one or more box frame members are affixed to the substandard roadway barrier using one or more glass fiber reinforced plastic (GFRP) sheets.

[0007] According to another embodiment of the present invention there is provided an upgraded roadway barrier comprising a concrete substandard roadway barrier and one or more box frame members secured to the substandard roadway barrier by one or more GFRP sheets.

[0008] According to still another embodiment of the present invention there is provided a kit for upgrading a substandard roadway barrier to a standard roadway barrier. The kit comprises one or more box frame members configured to be attached to an upper margin of the substandard roadway barrier and one or more GFRP sheets. The one or more box frame members generally comprise a trapezoidal prism configuration, andthe one or more GFRP sheets are configured to attach the one or more box frame members to the substandard roadway barrier and / or interconnect the one or more box frame members.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 depicts an exemplary box frame member constructed according to one embodiment of the present invention;

[0010] Fig. 2 depicts a plurality of box frame members mounted to a top surface of a substandard roadway barrier;

[0011] Fig. 3 depicts a plurality of box frame members and a horizontally-oriented GFRP sheet securing the box frame members to the substandard roadway barrier;

[0012] Fig. 4 depicts the assembly from Fig. 3 having further GFRP sheets securing the box frame members to the substandard roadway barrier;

[0013] Fig. 5 depicts the assembly from Fig. 4 having further GFRP sheets securing the box frame members to each other and to the substandard roadway barrier;

[0014] Fig. 6 depicts the assembly from Fig. 5 having a further GFRP sheet secured to the box frame members in order to seal off the area occupied by the box frame members;

[0015] Fig. 7 is a schematic depiction of an impact test apparatus awaiting deployment to test an upgraded roadway barrier; and

[0016] Fig. 7 is a schematic depiction of the pendulum of the impact test apparatus making contact with the upgraded roadway barrier.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] According to one or more embodiments, the present invention is adapted to modify existing substandard barriers to standard barriers to form an enhanced unitary body. As used herein, the term “substandard barrier” refers to a concrete roadway barrier having a height of 32 inches or less. As used herein, the term “standard barrier” refers to a concrete roadway barrier having a height of 42 inches or greater. The barrier upgrade components can be manufactured in two parts (a box frame and GFRP sheets). The components can be supplied as a repair kit that is quick to install.

[0018] In one or more embodiments, one or more box frame members 10 are provided. An exemplary box frame member 10 is depicted in Fig. 1, below, and can be manufactured from a resilient material such as steel (normal or high-strength steel). Frame member 10 comprises a plurality of segments 12 that have been affixed together, such as through welding, to form an open three-dimensional framework structure. Segments 12 can be solid or tubular elements. In certain embodiments, the box frame member 10 comprises six faces, preferably open faces having a window that communicates the interior of frame member 10 with the exterior environment, defined by respective segments 12. As can be seen in Fig. 1, a bottom face 14 is adapted for placement against an upper surface of a concrete roadway barrier and an opposing upper face 16. In preferred embodiments, bottom face 14 has a larger overall area than upper face 16. It is noted that the face areas described herein means the area that is bounded by the outer perimeter of the segments making up that face, which includes the aforementioned window. Each of faces 14, 16 preferably comprises a rectangular shape and resides in parallel planes.

[0019] Extending between bottom face 14 and upper face 16 are opposed front and rear faces 18, 20, and opposed side faces 22, 24. Front and rear faces 18, 20 can be of a generally rectangular shape and have approximately the same total area but reside in planes that are generally oblique to each other, thus faces 18, 20 are also referred to as oblique faces. As illustrated face 20 can be oriented substantially vertically and face 18 can be inclined at an acute angle relative to face 20. Alternatively, and depending upon the configuration of the concrete barrier to which members 10 are to be attached, both of faces 18, 20 can be oriented at an angle that is less than perpendicular to bottom face 14. In preferred embodiments, faces 18, 20 are configured to lie flush with respective faces of a substandard roadway barrier to which they are to be attached. Side faces 22, 24 can also be of approximately the same total area and reside in planes that are generally parallel to each other. Side faces 22, 24 preferably have a trapezoidal shape, thus giving box frame member 10 a generally trapezoidal prism configuration.

[0020] In certain embodiments, the box frame members have a height of at least 6 inches, at least 8 inches, or at least 10 inches, taken as the length between bottom face 14 andupper face 16. Thus, when installed on a concrete barrier the height of the barrier is extended by at least 6, 8, or 10 inches.

[0021] As depicted in Fig. 2, one or more box frame members 10 are attached to a substandard barrier 26. The one or more box frame members 10 can be secured to the barrier through the use of any suitable material, such as hardware fasteners, adhesives, or GFRP sheets. The use of GFRP sheets is depicted in Figs. 3-5. In certain embodiments, members 10 are identically configured, although, this need not always be the case. Optionally, reinforcing members 34 can be provided that interconnect adjacent frame members 10 to provide additional structural support for the extended portion of the barrier 26 that is formed by the frame members 10. Reinforcing members 34 can be in the form of rebar or GFRP rods, for example, that are affixed to frame members 10, such as with wire ties. In particular embodiments, the reinforcing members 34 can be secured to one or more corners of respective side faces 22, 24 of adjacent frame members. In one or more embodiments, the reinforcing members 34 can not only extend between adjacent frame members 10 but can also extend into the interior of the frame members running alongside top and / or bottom segments 12.

[0022] When frame member 10 is installed, bottom face 14 abuts a top surface 28 of the barrier 26. Also, front face 18 lies substantially flush with barrier front surface 30, and rear face 20 lies substantially flush with barrier rear surface 32. As can be seen, frame member 10 has an overall configuration that is essentially the same as that of barrier 26. Thus, when installed, frame member 10 appears as an extension of barrier 26.

[0023] As depicted in Fig. 3, an elongate GFRP sheet 36 has been positioned through frame members 10 and affixed over segments 12 making up bottom faces 14 and onto barrier top surface 28. Particularly, the GFRP sheet 36 extends through each of trapezoidally shaped side aces 22, 24 and interconnects all members 10 together and aids in securing frame members 10 to barrier 26. GFRP sheet 36 covers at least a portion of the segments 12 that make up bottom faces 14. The ends of GFRP sheet 36 can be affixed to side surfaces 38. GFRP sheet 36, and all other GFRP sheets described herein, may have applied thereto an epoxy composition to further strengthen the assembly and / or protect the box frames from corrosion. In certain embodiments, the GFRP sheets are saturated with the epoxy composition. As an example, the epoxy composition maycomprise the reaction product of an epoxide (e.g., epichlorohydrin) with a hardner or polyamine (e.g., tri ethylenetetramine). It is further noted that GFRP sheet 36 may be made up of individual strips or layers of GFRP material. Still further, box frame members 10 and the segments 12 making up members 10 can have an epoxy composition, which may be the same or different as that selected to saturate the GFRP sheets, applied thereto. The epoxy composition

[0024] Next, further GFRP sheets 40 are attached to one or more open faces of the box frame members 10 as shown in Fig. 4. As depicted, the GFRP sheets 40 are mounted over upper face 16, front face 18, and rear face 20 of at least one, and preferably all, of frame members 10. In certain embodiments, GFRP sheets 40 substantially cover faces 16, 18, and 20, particularly the open windows thereof. The GFRP sheets 40 also have ends that are affixed to the front and rear surfaces 30, 32 of the barrier 26 thereby further securing members 10 to barrier 26.

[0025] The box frame members 10 are then bridged by horizontally extending, elongate GFRP sheets 42 as depicted in Fig. 5. Sheets 42 overlie front face 18 and rear face 20. Optionally, sheets 42 can be extended to cover side faces 22 and 24 that lie flush with barrier side surfaces 38. Further, as shown in Fig. 6, an additional GFRP sheet 45 can be extended across upper faces 16 and side faces 22, 24, and also cover open spaces 44 located in between frame members 10 as well as side faces 22 and 24 that lie flush with barrier side surfaces 38. Therefore, in one or more embodiments, frame members 10 can be entirely enveloped with GFRP sheets thereby protecting frame members 10 from exposure to the elements, accumulation of dirt and other debris, and from corrosion.

[0026] It is further noted that the application of the various GFRP sheets 36, 40, 42 can be carried out in any order and need not occur in the sequence depicted in Figs. 3-5. Moreover, sheets 36, 40, 42 need not be entirely unitary and can be made up of individual, overlapping strips of GFRP material.

[0027] The box frame members 10 and associated GFRP sheets described herein can be used to form an upgraded roadway barrier. The box frame members 10 and GFRP sheets can be applied to a concrete substandard roadway barrier having a height of less than 42 inches in the manner described above to form an upgraded, standard roadway barrier having a height of at least 42 inches.

[0028] The components described herein can be provided as a kit for upgrading a substandard roadway barrier 36 to a standard roadway barrier. The kit can comprise one or more of box frame members 10 and one or more GFRP sheets that may be precut into sheets 36, 40, 42 or provided as sheets that can be cut by the end user to the appropriate sizes for application as described above. The kit may further include a quantity of reactants that are capable of forming an epoxy composition when mixed. The epoxy can then be applied to the GFRP material and / or portion of the substandard roadway barrier 36 to which the GFRP material is applied.

[0029] The robust, lightweight, quick, and relatively inexpensive upgrade technique described above can be easily used to protect bridge piers against truck crashes. The upgrade technique further satisfies the requirements of the AASHTO Load and Resistance Factor Design (LRFD) Specifications, 9thEdition, (incorporated by reference herein in its entirety) of extreme crash load events.

[0030] In one or more embodiments, once modified, the previous substandard barrier, now a standard barrier, is configured to withstand impacts to the barrier that are equivalent to a desired Test Level 4 (TL4). The impact can be delivered by a steel mass pendulumtype impactor 46 that is secured by metal frame members that keep the pendulum swing at a higher level to initiate a swinging impact upon its release through a downward sliding mechanism. See, Figs. 7-8. The swing angle is determined to induce the desired impact force that equals to the mass furnished times the acceleration developed through the curved swing path.

Claims

We claim :

1. A method of upgrading a substandard roadway barrier to a standard roadway barrier comprising: installing one or more box frame members on an upper margin of the substandard roadway barrier; and attaching the one or more box frame members to the substandard roadway barrier using one or more glass fiber reinforced plastic (GFRP) sheets.

2. The method of claim 1, wherein a plurality of the one or more box frame members are attached to the substandard roadway barrier, and wherein the plurality of box frame members are interconnected by one or more horizontally-installed GFRP sheets.

3. The method of claim 1 , wherein the substandard roadway barrier has a height of less than 42 inches, and wherein the upgraded standard roadway barrier has a height of at least 42 inches.

4. The method of claim 1, wherein the one or more box frame members have a height of at least 6 inches, at least 8 inches, or at least 10 inches.

5. The method of claim 1 , wherein the one or more box frame members are identically configured.

6. The method of claim 1 , wherein the one or more box frame members comprise a trapezoidal prism configuration.

7. The method of claim 1, wherein the one or more box frame members comprise a vertical face configured to lie flush with a vertical face of the substandard roadway barrier, and an opposed oblique face configured to lie flush with an oblique face of the substandard roadway barrier.

8. The method of claim 7, wherein the box frame member vertical and oblique faces are interconnected by opposed top and bottom rectangular faces and opposed trapezoidal side faces.

9. The method of claim 8, wherein the one or more box frame members are interconnected and secured to the substandard roadway barrier by an elongate GFRP sheet that extends through each of the opposed trapezoidal side faces and covers at least a portion of the bottom rectangular faces.

10. The method of claim 8, wherein the one or more box frame members are secured to the substandard roadway barrier by an elongate GFRP sheet that extends across the vertical face, the top face, and the oblique face of the box frame member.

11. The method of claim 7, wherein the one or more box frame members are interconnected by a first elongate GFRP sheet that extends across each oblique face and a second elongate GFRP sheet that extends across each vertical face.

12. The method of claim 1, wherein the one or more GFRP sheets are saturated with an epoxy composition.

13. An upgraded roadway barrier comprising: a concrete substandard roadway barrier; and one or more box frame members secured to the substandard roadway barrier by one or more GFRP sheets.

14. The upgraded roadway barrier of claim 13, wherein a plurality of the one or more box frame members are attached to the substandard roadway barrier, and wherein the plurality of box frame members are interconnected by one or more horizontally-installed GFRP sheets.

15. The upgraded roadway barrier of claim 13, wherein the substandard roadway barrier has a height of less than 42 inches, and wherein the upgraded standard roadway barrier has a height of at least 42 inches.

16. The upgraded roadway barrier of claim 13, wherein the one or more box frame members have a height of at least 6 inches, at least 8 inches, or at least 10 inches.

17. The upgraded roadway barrier of claim 13, wherein the one or more box frame members are identically configured.

18. The upgraded roadway barrier of claim 13, wherein the one or more box frame members comprise a trapezoidal prism configuration.

19. The upgraded roadway barrier of claim 13, wherein the one or more box frame members comprise a vertical face configured to lie flush with a vertical face of the substandard roadway barrier, and an opposed oblique face configured to lie flush with an oblique face of the substandard roadway barrier.

20. The upgraded roadway barrier of claim 19, wherein the box frame member vertical and oblique faces are interconnected by opposed top and bottom rectangular faces and opposed trapezoidal side faces.

21. The upgraded roadway barrier of claim 20, wherein the one or more box frame members are interconnected and secured to the substandard roadway barrier by an elongate GFRP sheet that extends through each of the opposed trapezoidal side faces and covers at least a portion of the bottom rectangular faces.

22. The upgraded roadway barrier of claim 20, wherein the one or more box frame members are secured to the substandard roadway barrier by an elongate GFRP sheet that extends across the vertical face, the top face, and the oblique face of the box frame member.

23. The upgraded roadway barrier of claim 19, wherein the one or more box frame members are interconnected by a first elongate GFRP sheet that extends across each oblique face and a second elongate GFRP sheet that extends across each vertical face.

24. The upgraded roadway barrier of claim 13, wherein the one or more GFRP sheets are saturated with an epoxy composition.

25. A kit for upgrading a substandard roadway barrier to a standard roadway barrier comprising: one or more box frame members configured to be attached to an upper margin of the substandard roadway barrier, the one or more box frame members comprising a trapezoidal prism configuration; and one or more GFRP sheets configured to attach the one or more box frame members to the substandard roadway barrier and / or interconnect the one or more box frame members.

26. The kit of claim 25, wherein the one or more box frame members have a height of at least 6 inches, at least 8 inches, or at least 10 inches.

27. The kit of claim 25, wherein the one or more box frame members are identically configured.

28. The kit of claim 25, wherein the one or more box frame members comprise a trapezoidal prism configuration.

29. The kit of claim 25, wherein the one or more box frame members comprise a vertical face configured to lie flush with a vertical face of the substandard roadway barrier, and an opposed oblique face configured to lie flush with an oblique face of the substandard roadway barrier.

30. The kit of claim 29, wherein the box frame member vertical and oblique faces are interconnected by opposed top and bottom rectangular faces and opposed trapezoidal side faces.

31. The kit of claim 25, further comprising a quantity of reactants operable to form an epoxy composition when mixed.

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