In Situ Evaluation of CFRP Strengthening for Corrosion-Deteriorated Bridge Bent Caps

Abstract

Deterioration of various elements of aging concrete highway bridges is a common and serious concern. The deterioration can be due to embedded rebar corrosion and associated concrete spalling, leading to member strength loss. The deterioration of bridge substructures and associated needs of repair/strengthening and evaluation has received much less attention than the superstructure. Concrete bridge bent caps may undergo age- and environmental exposure–related deterioration. In this study, eight such bent caps from a bridge built in 1940 near Dallas were selected for in-situ evaluation and rehabilitation. Following established protocols, the bent caps were repaired with epoxy mortar and then strengthened with a common unidirectional carbon-fiber-reinforced polymer (CFRP) laminate. Flexural CFRP strengthening together with CFRP U-wraps for confinement were utilized. Appropriate static and crawl speed load testing before and after repair/strengthening showed that the repair and strengthening process was effective in significantly increasing the bent cap stiffness and the effectiveness of the rehabilitation process.