Construction and Testing of GFRP Steel Hybrid-Reinforced Concrete Bridge-Deck Slabs of Sainte-Catherine Overpass Bridges

Hybrid reinforcement for concrete bridge-deck slabs is being investigated through a collaboration project between the Ministry of Transportation of Quebec (MTQ) and the University of Sherbrooke. This paper presents design concepts, construction details, and results of live-load field tests of the twin hybrid-reinforced bridges (P-15502N and P-15502S) on Sainte Catherine Road in Sherbrooke, Quebec (Canada). These hybrid-reinforced slab-on-girder bridges are simply supported over a single span of 43,415 mm. Their 200-mm-thick concrete deck slabs are continuous over four spans of 2,650 mm each, with an average overhang of about 1,000 mm on both sides (measured perpendicular to the girder axis). The deck slabs were reinforced with glass fiber–reinforced polymer (GFRP) reinforcing bars in the top mat and with galvanized steel bars in the bottom mat. One of the two bridges (P-15502S) was instrumented with fiber-optic sensors (FOSs) in the bridge-deck slab (over and between the girders). The instrumented bridge was tested for service performance with three calibrated truck loads prior to placement of the asphalt layer to check for flexural cracks. The construction details and the results of the live-load field tests are presented. The field tests yielded very small strains in the GFRP reinforcing bars, which clarified the arch-action effect in the restrained hybrid-RC bridge decks.