1. Evaluation of Corrosion Prevention and Mitigation Approaches Used on Texas Bridges—Volume 2: Reinforced Concrete Bridges
- Abstract
Corrosion in reinforced concrete is a self-accelerating process. As rust forms on steel, it enlarges in size and exerts tension on concrete, causing cracks and further corrosion in steel. The Texas Department of Transportation spends millions of dollars every year for repair and maintenance of concrete bridges; thus, a comprehensive study is essential to evaluate the corrosion resistance of concrete bridges across the state. In Texas, corrosion prevention and mitigation strategies for concrete decks involve the use of epoxy-coated rebar in addition to high-performance concrete. A calcium nitrite inhibitor, which increases the chloride threshold of concrete, is common in northern counties where a concrete accelerator is essential to achieve concrete strength during the early stages of winter. Additionally, surface treatments are also applied on concrete decks to reduce permeability of concrete. Findings of this research suggest that employing epoxy-coated rebar enhances the durability and corrosion resistance of reinforced concrete decks, while the use of uncoated black rebars can be still suitable for low corrosive environments. In the event that structures are located in highly corrosive regions such as marine environments and areas that heavily use deicing salt, the use of epoxy-coated rebar in addition to other mitigation strategies—like high-performance concrete—is recommended. Researchers also concluded that corrosion is inevitable in locations with surface cracking. In that case, corrosive agents can contact steel and initiate corrosion on reinforcing bars. Carbonation was determined to not be significant in inspected concrete decks unless cracks and concrete spalling happened. In general, most concrete decks inspected in this research were in acceptable condition except for a few cases that are documented within this report.
- Published
- 2024