BEARING CAPACITY OF WEB MEMBERS IN FIBER REINFORCEDPOLYMERIC (FRP) COMPOSITE BRIDGE DECKS

The primary purpose of this research project is to advance the understanding of fiber reinforced polymeric (FRP) composite bridge deck systems through the study of the bearing capacity of the vertical and offset diagonal webs of a stand-alone, multi-tube FRP composite bridge deck section. The overall rating capacity and ultimate strength capacity of the deck was determined from the testing sequence. The deck was sufficiently strong to withstand AASHTO HS25-44 type loading when tested directly over the vertical and offset diagonal webs. Load versus deflection data was collected for each testing position, and subsequently analyzed and adjusted to reflect assumptions with respect to the beam on an elastic foundation model and the development of the plastic hinge in the HS25-44 steel testing pads. By converting load deflection curves to equivalent stress versus strain curves, the experimental Modulus of Elasticity of each web was determined. In addition, a discussion on the behavior of the FRP panels under the specific testing conditions will be presented. Though the raw data collected from the series of eight bearing tests was not directly comparable, modifications and adjustments were made to remove initial nonlinearities, to replicate the beam on elastic foundation model, and to reflect a hypothetical situation in which all tests were performed with rigid steel test pads. From the adjusted curves, a better understanding of the true behavior of the composite FRP deck under the given AASHTO HS25-44 loading conditions can be realized and ultimately compared to future studies of the bearing capacity