Corrosion of Epoxy-Coated Rebar in Marine Bridges—Part 1: A 30-Year Perspective

Abstract

The corrosion performance over a nearly 30-year service period of epoxy-coated rebar (ECR) in Florida marine bridges is presented. Severe ECR corrosion was noted earlier in several of those bridges, built with relatively high permeability concrete. Corrosion development took place later in some other structures with less permeable concrete, with instances where the corrosion was associated with preexisting cracks. Corrosion was found to be associated with coating imperfections and coating disbondment. Laboratory experiments and modeling indicated that macrocell coupling with remote cathodes was an aggravating factor. Quantitative damage functions relating the observed deterioration with service time of the affected bridges are presented. A predictive corrosion initiation-propagation model was developed and the model output is compared with the field results to identify suitable parameters for forecasting future rehabilitation needs. The prognosis for future corrosion development is discussed, with attention to corrosion of ECR in otherwise low-permeability concrete with preexisting cracks or local deficiencies.

Influence of external loading and loading type on corrosion behavior of RC beams with epoxy-coated reinforcements

“…In addition, field surveys on corrosion performance of RC members constructed with epoxy-coated reinforcing bars were also investigated [11][12][13][14][15][16][17][18][19][20][21][22]. Although the first evidence of unsatisfactory field performance of epoxy-coated bars emerged in 1986 in bridges of the Florida Keys [12], many field investigations reported good performance of the epoxy-coated bars.…”

Corrosion Level of Rock Bolts Exposed to Aggressive Environments in Nordic Road Tunnels

“…It is well known that epoxy coatings are is very sensitive to damage during handling and transportation (Manning 1996;Sagüés et al 2010). A report described the setup of bolt corrosion research in the Oslofjord tunnel (Klemetsrud 2016), which considered painted galvanized steel bolts, observed unintended scratches and impurities in the epoxy coating after normal handling and before the test started.…”

Research on the Corrosion Behavior and Cathodic Protection of Defected-Epoxy-coated Reinforcement Exposed to Chloride Environment

“…However, the effectiveness of epoxy-coated rebar as a corrosion control method in reinforced concrete exposed to marine environment is still a controversial condition (Mao et al 2018, Sagues et al 1994. The long-term observation of epoxy coated rebar in marine bridges conducted in USA, illustrated a serious durability problem, and even pushed the forbidden of epoxy coated rebar applied in marine structures (Kessler et al 2001, Sagues et al 2010, Sagues et al 1996). However, the other studies revealed that the epoxy coated rebar could still be used as an alternate to steel after the coating was modified (Rahman, et al 2022).…”