PLURAL-COMPONENT, COMPOSITE-MATERIAL HIGHWAY DOWEL BAR STRUCTURE AND FABRICATION METHODOLOGY

• US 20130202355A1
• Filed: 01/31/2013
• Published: 08/08/2013
• Est. Priority Date: 02/04/2012
• Status: Active Grant

• Current Assignee: Composite Rebar Technologies, Inc.
• Original Assignee: Composite Rebar Technologies, Inc.
• Inventors: Gibson, Robert C., Garber, Trent J., Noble, Matthew H.
• Granted Patent: US 8,591,139 B2
• Time in Patent Office: Days
• US Class Current: 404/59
• CPC Class Codes: B29C 69/001 a shaping technique combined with cutting, e.g. in parts or slices combined with rearranging and joining the cut parts for reinforced material B29C70/545; B29C49/4278, B29C51/268 take precedence
• CPC Class Codes: B29C 70/021 Combinations of fibrous reinforcement and non-fibrous material
• CPC Class Codes: B29C 70/52 Pultrusion, i.e. forming and compressing by continuously pulling through a die
• CPC Class Codes: B29C 70/521 and impregnating the reinforcement before the die
• CPC Class Codes: B29C 70/865 completely encapsulated
• CPC Class Codes: B29K 2705/00 Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts
• CPC Class Codes: E01C 11/14 Dowel assembly ; Design or construction of reinforcements in the area of joints coupling devices for prefabricated units E01C5/005; combined with characteristic packings E01C11/08 - E01C11/12; removable holders E01C23/045

Abstract

A plural-component, composite-material highway dowel bar and an associated fabrication methodology. The dowel bar includes an elongate, solid-cylindrical, high-shear-strength core bar, preferably steel, and an elongate, fibre-reinforced plastic-resin jacket, including an elongate, pultrusion-formed, tubular sleeve, and sleeve-received, opposite-end, end-well sleeve end plugs, fully surrounding and protectively covering the core bar.

Claims

1. A plural-component, composite-material highway dowel bar comprising

an elongate, cylindrical, high-shear-strength core, and

an elongate, fibre-reinforced plastic-resin jacket fully surrounding and protectively covering the entirety of said core.

2. The dowel bar of claim 1, wherein said jacket includes (a) an elongate, cylindrically tubular sleeve which is (1) fibre-reinforced in plural, plastic-resin-embedded, fibre-differentiated, circumferentially-adjacent circumferential layers of fibres, (2) longer than said core, and (3) configured with a hollow, cylindrical inside which bondedly receives said core in a manner defining opposite-end, cylindrical end wells that are disposed within the sleeve beyond opposite ends of the received core, and (b), a pair of spaced, elongate, fibre-reinforced, cylindrical, sleeve end plugs bondedly affixed, one each, complementarily within said end wells.

3. The dowel bar of claim 2 which possesses a long axis, and wherein said circumferentially-adjacent, fibre-differentiated, circumferential layers include different, respective, characters of sleeve-included fibres which fake the forms of (1) elongate, linear, plural-elongate-fibre-including, glass-fibre roving material whose included fibres substantially parallel said long axis, (2) continuous-glass-fibre mat material, and (3), glass-fibre veil material, and said fibre-reinforced sleeve end plugs include glass-fibre roving also possessing plural, elongate fibres which substantially parallel said long axis.

4. The dowel bar of claim 3, wherein said fibre-reinforced, circumferentially-adjacent, circumferential layers of fibres in said sleeve possess an arrangement which, progressing radially outwardly in the sleeve from its inside, takes the form, generally, of a first-encountered, mat-material layer, a later-encountered, roving-material layer disposed outwardly of said mat-material layer, and an even later-encountered veil-material layer disposed outwardly of said roving-material layer.

5. The dowel bar of claim 4, wherein said arrangement further includes a second mat-material layer disposed intermediate said later-encountered roving-material layer and said even later-encountered veil-material layer.

6. The dowel bar of claim 1, wherein said core is formed of steel.

7. The dowel bar of claim 6, wherein said jacket includes (a) an elongate, cylindrically tubular sleeve which is (1) fibre-reinforced in plural, plastic-resin-embedded, fibre-differentiated, circumferentially-adjacent circumferential layers of fibres, (2) longer than said core bar, and (3) configured with a hollow, cylindrical inside which bondedly receives said core bar in a manner defining opposite-end, cylindrical end wells that are disposed within the sleeve beyond opposite ends of the received core bar, and (b), a pair of spaced, elongate, fibre-reinforced, cylindrical, sleeve end plugs bondedly affixed, one each, complementary within said end wells.

8. The dowel bar of claim 7 which possesses a long axis, and wherein said circumferentially-adjacent, fibre-differentiated, circumferential layers include different, respective, characters of sleeve-included fibres which take the forms of (1) elongate, linear, plural-elongate-fibre-includings glass-fibre roving material whose included fibres substantially parallel said long axis, (2) continuous-glass-fibre mat material, and (3), glass-fibre veil material, and said fibre-reinforced sleeve end plugs include glass-fibre roving also possessing plural, elongate fibres which substantially parallel said long axis.

9. The dowel bar of claim 8, wherein said fibre-reinforced, circumferentially-adjacent, circumferential layers of fibres in said sleeve possess an arrangement which, progressing radially outwardly in the sleeve from its inside, takes the form, generally, of a first-encountered, mat-material layer, a later-encountered, roving-material layer disposed outwardly of said mat-material layer, and an even later-encountered veil-material layer disposed outwardly of said roving-material layer.

10. The dowel bar of claim 9, wherein said arrangement further includes a second mat-material layer disposed intermediate said later-encountered roving-material layer and said even later-encountered veil-material layer.

11. A plural-component, composite-material, highway dowel-bar making method comprising

preparing an elongate core train having a long axis, and possessing, along that axis, endo-abutting, longitudinally alternating, (a) elongate, high-shear-strength, cylindrical cores having a common, certain cross section, and (b) elongate, but shorter, cylindrical, fibre-reinforced plastic-resin end-plug blanks having opposite ends, and each having a cross section matching the certain cross section of the cores.

using the core train as a longitudinally moving mandrel, pultrusion-forming a fibre-reinforced plastic-resin sleeve continuously and bondedly around the core train so as to produce a pultrusion-result, intermediate, dowel-bar product, and

following said pultrusion-forming, cross-cutting the intermediate, dowel-bar product at each longitudinal location therein which is intermediate the opposite ends of the end-plug blanks, and thereby forming completed dowel bars.

12. The method of claim 11, wherein said pultrusion-forming is preceded by (a) paying out, from suitable supplies, continuous, elongate runs of reinforcing fibre materials, (b) bathing these materials runs in curable, liquid plastic resin, and guiding the bathed runs info circumferential layer structure for pultrusion in a tubular region circumsurroundingly disposed relative to the outside of the prepared core train.

13. The method of claim 12, wherein the reinforcing fibre materials include (1) glass-fibre roving possessing plural, elongate, linear fibres, (2) continuous-glass-fibre mat, and (3), glass-fibre veil, and said paying out and guiding steps collaboratively perform arranging of the different reinforcing fibre materials whereby, relative to the outside surface of the core train during the subsequent pultrusion-sleeve-forming step, mat material becomes disposed as part of an innermost pultrusion layer, veil material becomes disposed as pad of an outermost pultrusion layer, and roving material becomes part of a layer which is intermediate these innermost and outermost layers, with its included, elongate fibers disposed with their long axes substantially paralleling the core train'"'"'s long axis.

14. The method of claim 11 which further comprises heating the high-shear-strength cores prior to said pultrusion-forming.

15. The method of claim 11 which further comprises performing pultrusion-forming in a heated environment.