Simulations of fire temporal thermal behaviour of fibre reinforced polymer bridge decks

Recent attention has been focused on Fibre Reinforced Polymer (FRP) as an alternative material for bridge construction. A significant concern in the applications of FRP composite materials is the possibility of an accidental fire. The post-fire mechanical properties of FRP bridge decks decrease rapidly with increasing heat exposure time and heat flux due to combustion of the polymer matrix and heat degradation. Finite element method (FEM) has been employed to study the structural behaviour of the FRP bridge deck under thermal effects. The finite element model was verified with the field-test results, provided by New York State Department of Transportation (NYSDOT). This study describes the behaviour of the FRP bridge deck on a truss bridge subjected to thermal loading from truck fire incident combined with mechanical loading from commercial trucks. Fully coupled thermal- stress analyses were performed using FEM to determine fire resistance limit, which is defined as the time period from the initiation of fire until the moment that failure occurs at any part of the FRP deck. Thermal simulations showed that the FRP bridge deck is highly sensitive to the effect of elevated temperatures.