Plural-component, composite-material highway dowel bar fabrication methodology

• US 9,440,400 B2
• Filed: 09/21/2013
• Issued: 09/13/2016
• 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., Noble, Matthew H., Garber, Trent J.
• Primary Examiner(s): KENNEDY, TIMOTHY J
• Application Number:
  US14/033,461
• Publication Number:
  US 20140021647A1
• Time in Patent Office: 1,088 Days
• Field of Search: 264/149
• US Class Current: 1/1
• 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 method for making a plural-component, composite-material, highway dowel-bar including (1) preparing an elongate core train possessing endo-abutting, longitudinally alternating, (a) elongate, high-shear-strength, cylindrical cores having a common cross section, and (b) elongate, but shorter, cylindrical, fiber-reinforced plastic-resin end-plug blanks having opposite ends, and each having a cross section matching the cross section of the cores, (2) using the core train as a longitudinally moving mandrel, pultrusion-forming a fiber-reinforced plastic-resin sleeve continuously and bondedly around the core train so as to produce a pultrusion-result, intermediate, dowel-bar product, and (3) following 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, thereby to form completed dowel bars.

Claims

1. 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, cylindrical cores, each core having a common, constant cross section at every location along the long axis, and (b) elongate, but shorter, cylindrical, fibre-reinforced plastic-resin end-plug blanks having opposite ends, and each end-plug blank having a constant cross section at every location along the long axis matching the constant 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 longitudinal locations therein which are intermediate the opposite ends of end-plug blanks, and thereby forming completed dowel bars.

2. The method of claim 1, 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 into circumferential layer structure for pultrusion in a tubular region circumsurroundingly disposed relative to the outside of the prepared core train.

3. The method of claim 2, 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 part 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.

4. The method of claim 1 which further comprises heating the cores prior to said pultrusion-forming.

5. The method of claim 1 which further comprises performing pultrusion-forming in a heated environment.

6. A method of manufacturing a composite-material highway dowel-bar, the method comprising:

providing a train of cylindrical steel cores along a long axis, with each adjacent pair of steel cores separated by a single cylindrical blank;

forming a fiber-reinforced plastic-resin sleeve around the train by passing the train through a pultrusion die, thereby forming an intermediate dowel-bar product; and

cutting through the intermediate dowel-bar product to form completed dowel-bars;

wherein cutting through the intermediate dowel-bar product includes cutting through each blank so that a first portion of each blank is included in a first completed dowel-bar and a second portion of each blank is included in a second completed dowel-bar.

7. The method of claim 6, wherein each of the cylindrical steel cores has constant cross-section along the long axis and each cylindrical blank has a constant cross-section along the long axis matching the constant cross-section of the steel cores.

8. The method of claim 6, wherein the fiber-reinforced plastic-resin sleeve includes (a) an outermost layer including veil material, (b) an innermost layer including mat material, and (c) an intermediate layer between the innermost and outermost layers including elongate fibers disposed with their long axes substantially parallel to the long axis of the train.