MPC Research Reports
Report Details

Title:	Performance of Steel Girders Repaired with Advanced Composite Sheets in a Corrosive Environment
Authors:	Yail Jimmy Kim
University:	University of Colorado Denver
Publication Date:	Jun 2017
Report #:	MPC-17-325
Project #:	MPC-456
TRID #:	01640935
Keywords:	beams, carbon fibers, composite materials, deterioration, durability, electrochemical corrosion, failure, fiber reinforced polymers, girders, recommendations, steel bridges

Abstract

This report presents a two-phase research program studying i) galvanic current influencing deterioration of carbon fiber reinforced polymer (CFRP) sheets bonded to a steel substrate and ii) electrochemical reaction for steel beams strengthened with CFRP. The first phase of the research presents an experimental program investigating the effect of galvanic current on the physical and mechanical characteristics of CFRP composite sheets bonded to a steel substrate. Electrochemical reaction is induced by galvanic interaction between anodes (CFRP-steel interface specimens) and cathodes (metallic strips) linked with an electrolyte (a 3.5% sodium chloride solution). Thirty five test specimens are exposed to various periods of galvanic current from 0 to 72 hours until their corrosion rate is converged. Hydrated ferric oxide forms along the CFRP-steel interface with some concentration in the vicinity of its edge, which accompanies a loss in surface area and mass. The electrochemical reaction imposed by the galvanic current exponentially decays with an increase in exposure time. The second phase of the research discusses the effects of an electrochemical reaction on the physical and chemical responses of steel beams strengthened with carbon fiber reinforced polymer (CFRP) sheets. An accelerated corrosion protocol is used for deteriorating the strengthened beams. Emphasis is placed on the electric potential, mass loss, corrosion current density, corrosion rate, flexural capacity, interfacial strain development, failure mode, and infrared spectroscopy of the beams. Corrosion damage is dispersed with increasing electrochemical reaction time; however, premature CFRP-debonding is not observed.

How to Cite

Kim, Yail Jimmy. Performance of Steel Girders Repaired with Advanced Composite Sheets in a Corrosive Environment, MPC-17-325. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2017.