Polypropylene FRC Bridge Deck Slabs Transversely Prestressed with CFRP Tendons

Compressive membrane action in bridge deck slabs has been shown to considerably increase the failure loads of such slabs. Thus, the reinforcing requirement can be reduced if a system is configured to ensure development of compressive membrane action. Recent research has shown that the use of transverse prestressing in bridge deck slabs can achieve even greater savings by reducing slab thickness and reinforcing requirements while enhancing serviceability. This paper describes an investigation of a deck slab system totally devoid of steel reinforcement. A one-quarter-scale model of a typical deck slab supported on three steel girders was constructed in the laboratory and transversely prestressed with carbon-fiber-reinforced plastic tendons. Polypropylene-fiber-reinforced concrete was used for temperature and shrinkage crack control. The deck slab panels in the model bridge were tested to failure under simulated concentrated wheel loads. The observed failure mode of all panels was that of punching shear, at loads in excess of the scaled Ontario Highway Bridge Design Code specified design service load. Load-deflection curves and failure loads are presented and compared. The test results show that transverse prestressing enhances, considerably, the punching failure loads of deck slabs. It was also observed that bridge deck slabs totally devoid of any steel reinforcement perform satisfactorily in both strength and deformation.