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Title:Composite Repair of Railroad Crossties through the Process of Shear Spiking
Authors:TJ Thorne Schilling, Richard M. Gutkowski, and Don Radford
University:Colorado State University
Publication Date:Jun 2004
Report #:MPC-04-163
Project #:MPC-214
TRID #:00978844
Keywords:epoxy resins, fiber reinforced plastics, flexural strength, load tests, maintenance, polymer fibers, railroad tracks, repair and maintenance businesses, shear properties, spikes, stiffness, track components, wood ties



Investigations into the effects Z-spiking with fiber reinforced polymer (FRP) rods have on the flexural stiffness and repair of deteriorated railroad crossties were conducted. These tests were conducted to provide a pilot study for an ultimate goal of repairing full-scale bridges. This report presents the results found from flexural load testing conducted on deteriorated Douglas fir railroad crossties reinforced with FRP shear spikes; epoxy-resin shear strength testing; and finite element modeling of repaired crossties. Reinforcement was provided by installing 12.7mm (0.5in.) diameter polyglass polyester resin fiberglass rods bonded in place using epoxy-resin. The rods were inserted into the deteriorated railroad crossties perpendicular to the primary bending axis to provide horizontal shear reinforcement and improve flexural stiffness. Shear spikes were installed in pairs starting at each end of the crosstie specimen and moving inward. Load tests were conducted to determine the gain in effective stiffness as the number of spikes increased. A total of ten rows were sequentially inserted into each crosstie specimen with load tests performed after each successive row installation. Results from load tests show an average increase in flexural stiffness of 58 percent with all ten rows of shear spikes inserted into the crossties. The results show the use of FRP shear spikes as a reinforcement method dramatically increased the flexural stiffness of railroad crossties and helped to offset the deterioration present from decay. In addition, the shear spikes and epoxy-resin show a strong possibility for repairing decay voids present on the surface of the deteriorated crossties as well as their interior portions.

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