Methods of Corrosion Protection and Durability of Concrete Bridge Decks211 Reinforced with Epoxy-Coated Bars. Phase 1

摘要

In this study, the results of an extensive field and laboratory investigation211u001econducted to evaluate the corrosion performance of epoxy-coated reinforcement are 211u001ereported. The results from the holiday testing showed that an average of 31 211u001eholidays per meter (9 holidays per foot) were created during the concrete casting 211u001eoperation. Increasing the coating thickness by 101.6 micrograms (4 mils) and 211u001elowering the hose used when pumping concrete to the level of the top mat of 211u001ereinforement reduced the holidays created to to 11.5 holidays per meter (3.5 211u001eholidays per foot) after casting. The results of 16 specimens subjected to cycles 211u001eof exposure in the laboratory evaluation indicated that if the mat to mat 211u001eresistance was greater than 5000 ohms, then over the 77-week period no corrosion 211u001eactivity was observed. No corrosion activity occurred even though the chloride 211u001elevels at the reinforcement location were well above 0.79 kg/cu m(1.3 211u001elb/yd(cubed)), the threshold level for initiation of corrosion. A possible way to 211u001eachieve a high mat to mat resistance would be by limiting the damage to the epoxy 211u001ecoatings.