GFRP REINFORCED CONCRETE BRIDGES

This report investigates the application of glass fiber reinforced polymer (GFRP) rebars in concrete bridge decks as a potential replacement or supplement to conventional steel rebars. Tests were conducted to determine the material properties of the GFRP reinforcement, and experiments were performed to study aspects of GFRP rebar placement in actual bridge decks. These included observation of GFRP rebar handling characteristics and worker response during construction. Load tests of full-scale reinforced concrete specimens were conducted to evaluate the characteristics of three reinforcing schemes: (1) an epoxy coated steel (ECS) reinforcing scheme; (2) a GFRP reinforcing scheme, and (3) a hybrid reinforcing scheme combining GFRP and ECS rebars. Results of the investigation showed that the moduli of elasticity in tension and compression for the GFRP rebars were approximately the same, but the ultimate strength in compression was 50% of the ultimate strength in tension. Several recommendations were made for construction and repair procedures for decks reinforced with GFRP rebars. Modifications are suggested to existing theoretical expressions for predicting ultimate shear strength and maximum crack width of GFRP reinforced concrete members. The results of this study show that bridge decks reinforced with GFRP rebars satisfy the American Association of State Highway and Transportation Officials (AASHTO) specifications for strength. AASHTO's crack width requirements were not satisfied.