Innovative FRP Reinforced Concrete Bridges with Extended Service Life

This paper presents the design, construction details, and the results of field load testing and finite element modeling of four innovative concrete bridges. These bridges have been recently constructed in North America utilizing FRP composite bars as internal reinforcement for the concrete deck slabs. Three bridges, Magog, Cookshire-Eaton, and Val-Alain Bridges are located in Quebec, Canada, while the fourth one, Morristown Bridge, is located in Vermont, USA. The four bridges are girder-type with main girders made of either steel or prestressed concrete. The main girders are supported over spans ranging from 26.2 to 50.0 m. The bridge deck is a 200 to 230 mm thick concrete slab continuous over spans of 2.30 to 3.15 m. Different types of glass and carbon FRP reinforcing bars as well as conventional steel bars were used as reinforcement for the concrete deck slab. The four bridges are located on highways of different categories, which mean different traffic volumes and environmental conditions. The bridges are well instrumented at critical locations for internal temperature and strain data collection using fiber optic sensors. These gauges are used to monitor the deck behavior from the time of construction to several years after the completion of construction. The four bridges were tested for service performance using calibrated truckloads. In parallel, a finite element analysis (FEA) was conducted and verified against the results of the field load tests. The FEA was, then, used to verify the design and serviceability of the bridge decks. The analytical and field results, in terms of deflections, cracking, and strains in the reinforcement and concrete, under real service conditions showed a comparable performance of the FRP reinforced concrete bridge deck slabs to the steel reinforced ones.