Field Investigation of the Corrosion Protection Performance of Bridge Decks andPiles Constructed with Epoxy-Coated Reinforcing Steel in Virginia

摘要

The corrosion protection performance of epoxy-coated reinforcing steel (ECR) wasassessed in three bridge decks and the piles in three marine structures in Virginia in 1996. The decks were 17 years old, two of the marine structures were 8 years old, and the other marine structure was 7 years old at the time of the investigation. The deck investigations included visually surveying surface cracks in the right traffic lane and drilling 12 cores randomly located in the lowest 12th percentile cover depth. The pile investigations included removing 1 core at an elevation between high and low tides from each of 30 piles. The evaluation of the concrete in each core included visually inspecting and measuring moisture content, absorption, percent saturation, carbonation depth, and effective chloride diffusion constant. The evaluation of the ECR from each core included visually inspecting and measuring physical damage, coating thickness, adhesion loss and corrosion at damaged sites, and undercoating corrosion at adhesion test sites. The chloride content of the concrete and the carbonation of the ECR trace were also determined for each core. In the majority of bars examined, the epoxy coating has debouded or is debonding from the reinforcing bar. This occurs without the presence of chloride, and its rate is related to concrete moisture conditions, temperature, coating defects, and other bar and coating properties. Based on the results of this field study, epoxy coatings can be expected to debond from reinforcing steel in Virginia's marine environments in about 6 years and from bridge decks in about 15 years.