ELIMINATING STEEL FROM BRIDGE DECK SLABS BY COMBINING CFRP TENDONS WITH POLYPROPYLENE FRC

摘要

Compressive membrane action in bridge deck slabs has been shown to increase considerably 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.rnThis paper describes an experimental program to examine the suitability of combining carbon fibre reinforced plastic (CFRP) prestressing rods with polypropylene fibre reinforced concrete (FRC) to create a bridge deck slab totally devoid of steel. The polypropylene fibres are included mainly to control temperature and shrinkage cracking. Such a system should provide a more durable alternative to conventional decks because of the resistance to corrosion of the CFRP rods and the polypropylene fibres. A 1/4 scale model of a typical deck slab supported on three steel girders was constructed in the laboratory and transversely prestressed with 12 CFRP rods. Three different polypropylene fibre concentrations were used in the three independent bays, each having two panels, of the bridge deck. Each panel was tested to failure under simulated concentrated wheel loads. The measured load-deflection curves for the slab are presented. Additionally, the punching failure loads are compared with the Ontario Highway Bridge Design Code (OHBDC) design wheel load.