Deterioration of bridge decks caused by corrosion of reinforcing bars canbe a major problem. Chloride ions from deicing salts are the main culprit responsible for the premature deterioration of reinforced concrete bridge decks because they can induce corrosion of the reinforcing steel. Voluminous corrosion products exert hoop stress on the surrounding concrete, resulting in cracking and spalling. In the mid 1970s, corrosion engineers and the coating industry introduced epoxy-coated reinforcing bar (ECR)as a means of extending the service life of highway structures by minimizing corrosion of the reinforcing steel. Currently, 48 state highway agencies use ECR as the most common corrosion protection system for bridge decks. According to 2003 data in Federal Highway Administration's (FHWA) National Bridge Inventory, more than 54,000 bridge decks contain ECR. This articlereviews the testing and results of an FHWA 5-year laboratory test projecttitled Corrosion Resistant Reinforcing for Concrete Components. The results indicated that using American Society for Testing and Materials specified ECR applied by a certified coater in both top and bottom mats as the primary corrosion protection system coupled with high performance concretesand a minimum 2.5" cover is the most economical and cost effective methodto build durable bridge decks until alternative reinforcements, such as solid stainless steel bars and stainless steel-clad bars possessing excellent corrosion resistance properties become readily available.
Samenvatting