Design and Testing of a Highway Concrete Bridge Deck Reinforced with Glass and Carbon FRP Bars

摘要

A new highway bridge was constructed using FRP bars as reinforcement for the concrete deck slab. The bridge, located on highway 55 North over the Magog River (Quebec, Canada), is a girder type with a total length of 83.7 m and five main steel girders continuously supported over three spans. The two end spans are 26.2 m each and the middle one is 31.3 m. The deck is a 220-mm thickness concrete slab continuous over four spans of 2.845 m each with an overhang of 1.352 m on each side. One full end span (26.2 m) was totally reinforced with FRP bars in top and bottom mats. The other two spans of the bridge were reinforced with galvanized steel. The steel reinforced concrete deck slab was designed according to Section 8 of the New Canadian Highway Bridge Design Code, CHBDC (CAN/CSA-S6-00 2000). The steel reinforcement was then replaced with FRP bars according to Section 16 of CHBDC (CAN/CSA-S6-00 2000). This design resulted in using glass FRP bars (No. 16 - 15.9 mm-diameter) in all directions except in the transverse direction on the bottom mat where carbon FRP bars (No. 10 - 9.5 mm-diameter) were used. The construction of the bridge was completed on September 2002 and opened for traffic during the second week of October 2002. Before opening to the traffic, the bridge was tested for service performance using standard truckloads as specified in the new CHBDC (CAN/CSA-S6-00 2000). During all load tests, strains in FRP and steel reinforcements and deflections of FRP and steel reinforced spans (slabs and girders) were recorded. Design, construction details, and the results of this first series of field tests are discussed in this paper.