METHOD FOR FOLDABLE FRP REINFORCEMENT SYSTEM

Abstract

Method for connecting rebar intersections of a foldable FRP rebar cage to allow folding and unfolding of the cage to facilitate transportation one or more rebar cages.

Claims

1. (canceled)

2. (canceled)

3. (canceled)

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. A method for making, collapsing, transporting and reforming a plurality of rebar cages, comprising the steps of: making a plurality of rebar cages at a first location, by for each cage, taking the steps of providing a plurality of FRP vertical rebar members and a plurality of FRP stirrup rebar members; arranging the plurality of FRP vertical rebar members and the plurality of FRP stirrup rebar members to form a plurality of intersections; positioning a tie having first and second ends across each intersection of the plurality of FRP vertical rebar members and the plurality of FRP stirrup rebar members and securing the first and second tie ends to each other to secure them to the intersection to thereby form a rebar cage, the rebar cage have a first volume, the tie being shaped to allow the FRP vertical rebar member and the FRP stirrup rebar member at the intersection to move with respect to each other, collapsing each rebar cage so it has a second volume, the second volume being less than the first volume; placing the plurality of collapsed rebar cages on a vehicle; moving the vehicle and collapsed rebar cages to a construction site; removing the rebar cages from the vehicle; reforming the collapsed rebar cages to their first volumes.

9. The method of claim 8 wherein a plurality of the ties are twist ties.

10. The method of claim 8 wherein a plurality of the ties are wire.

11. The method of claim 8 wherein a plurality of the ties are zip ties.

12. The method of claim 8 further comprising the step of lacking at least one of the reformed rebar cages in a concrete form.

13. The method of claim 8 wherein the plurality of FRP vertical rebar members have a first diameter and the plurality of FRP stirrup rebar members have a different diameter.

14. The method of claim 8 wherein the rebar cages in their uncollapsed shape are cylindrical.

15. The method of claim 8 wherein the vertical rebar members and the stirrup rebar members are comprised of GFRP rebar.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 shows the inefficient dead space on a trailer transporting prior art steel concrete reinforcement systems.

[0009] FIGS. 2, 3 and 4 show a columnar rebar cage in an unfolded, partially folded, and fully folded orientation, respectively.

[0010] FIGS. 5 and 6 show an unfolded rebar mesh and a folded rebar mesh, respectively.

[0011] FIG. 7 shows an upper portion of a clip connector having a sphere.

[0012] FIG. 8 shows a lower portion of a clip connector having arms that received the sphere of the upper portion shown in FIG. 7.

[0013] FIG. 9 shows a clip connector with the upper and lower portions engaged by the sphere/arms combination.

[0014] FIGS. 10 and 11 show rebar held by the clip connector and how the rebar may be pivoted about multiple axes due to the spherical-arm construction.

DETAILED DESCRIPTION

[0015] In one embodiment, the invention comprises a rebar cage made of GFRP rebar. The intersections of the rebar cage may be held together either by conventional twist ties, or by pivotable connectors as described further below. GFRP rebar is sufficiently light to allow conventional rebar ties to be employed. In this embodiment, a rebar cage is manufactured in a desired shape, such as a cylinder as shown in FIG. 2. In this embodiment, there are four vertical members 1 and four circular stirrup members 2. A rebar connector is at each intersection of rebar and is of sufficient strength to maintain the shape of the rebar cage. In FIG. 2, the first set of two opposing vertical rebar members are held to stirrups by clips 3 as described further below, and the second set of two opposing vertical rebar members are held to stirrups by conventional wire ties. In addition, in this embodiment, the rebar is GFRP rebar, making the entire rebar case sufficiently lightweight for a person to lift and fold. Because GFRP rebar is lighter than steel rebar, the connectors holding the intersections together will not fatigue or break due to the folding as described below.

[0016] The clip connectors 3 (as opposed to the tie-wire connectors) may be hingedly or pivotally connected to each other and sized to receive rebar. The clip connectors may be joined by a hinge, which allows them to rotate in a single plane, or they may be joined by a spherical member. The clips may be made of polyethylene which is sufficiently flexible for the channel sides 5 of each clip to be pushed against rebar until the rebar enters the cylindrical channel 6 between the sides. Connectors 3 generally allow intersecting rebar to be held together at the intersection faster than the time required to use a twist tie. In addition, for rebar that is lightweight, such a GFRP, the clips may be formed of lightweight polyethylene. The clips may have different sizes to accommodate instances in which the widths of the rebar that intersect have different widths.

[0017] Once the rebar intersections have been provided with connectors (either clips or conventional twist-ties), the rebar intersections may be simultaneously pivoted to fold or collapse the rebar cage. FIG. 3 shows a partially folded rebar cage, and FIG. 4 shows a fully folded rebar cage.

[0018] The rebar cage shown in these figures is comprised of GFRP rebar, which is sufficiently light to allow the rebar intersections to be held by the connectors so the connectors do not break or become detached from the rebar.

[0019] It will be appreciated that in FIGS. 2-4, the only two opposing side vertical rebar pieces attach to connectors having connectors, while the front and rear vertical rebar members are connected using conventional twist-ties. This is because the design of the above hinged-clip connectors allow the clips to pivot around only one axis. Alternatively, a connector design that allows pivoting of clips in all orientations is shown in FIGS. 7-11.

[0020] The present invention includes use with mesh rebar as shown in FIGS. 5 and 6. Mesh rebar comprises straight rebar members oriented in a perpendicular orientation as shown in FIG. 5. The rebar connectors allow the mesh to be folded into a compact configuration as shown in FIG. 6.

[0021] By providing collapsible and re-formable rebar structures, the structures may be formed away from a construction site, collapsed or folded, transported to the construction site, and then unfolded or re-formed at the construction site. This allows much more efficient operations.

[0022] FIGS. 7 and 8 respectively show the upper and lower portions of a connector. Upper portion includes a spherical member 10, and the lower portion that includes multiple arms 4, such as four arms as shown. The arms 4 of the lower portion are sufficiently flexible to be pressed into the spherical member 10 of the upper portion. This allows the upper portion to fully rotate in the X and Y axes with respect to the lower portion, and, to also pivot in the Z axis to the extent the arms of the lower portion do not interfere with the upper portion. This advantageously permits the connector to be used to connect all rebar intersections while allowing sufficient flexibility to allow rebar cages to be folded and unfolded. Each of the upper and lower portions has sides forming a substantially cylindrical channel 6 that my receive rebar. The channel sides 5 are flexible enough to allow them to be pressed over rebar 11 to secure it to the connector. The cylindrical channels of each of the upper and lower portions may be of differing diameters. This makes them suitable of use when the two rebars of different widths form an intersection.

[0023] Those of skill in the art will understand that various details of the invention may be changed without departing from the spirit and scope of the invention. Furthermore, the foregoing description is for illustration only, and not for the purpose of limitation, the invention being defined by the claims.

[0024] While the invention has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as illustrative and not restrictive in character, it being understood that only illustrative embodiments thereof have been show and described and that all changes and modifications that are within the scope of the following claims are desired to be protected.

[0025] All references cited in this specification are incorporated herein by reference to the extent that they supplement, explain, provide a background for or teach methodology or techniques employed herein.