Rasmus Walter

Debonding of FRC Composite Bridge Deck Overlay

ABSTRACT A new type of composite bridge deck is currently under research. The concept is to achieve composite action by the adhesion between a thin layer of fiber reinforced concrete cast on a steel plate. Of special concern is the strength of the bond between the concrete and steel plate in the case of vertical cracking of the overlay. Based on a nonlinear 2D finite element model a theoretical parameter study has been conducted in relation to debonding of a concrete overlay. Discrete crack theory was used to model vertical cracking of the overlay and interfacial cracking (debonding) between the steel plate and concrete. Two parameter studies were made. One concerns the fracture energy of the overlay and steel-concrete interface. These results show that the composite performance is dependent primarily on fracture energy of the concrete overlay, and less on the fracture energy of the steel-concrete interface. In the other, the mixed mode behaviour of the steel-concrete interface is studied in relation to the interfacial failure criterion.