Behavior of orthotropic fiber reinforced polymer bridge decks on traditional girders.

摘要

Fiber reinforced polymer (FRP) sandwich decks can be used to replace deteriorated reinforced concrete decks. A combination of their light weight and the fact that the members are fabricated and brought to the site means that traffic delays will be decreased versus recasting a reinforced concrete deck. FRP decks do not contain reinforcing steel, therefore corrosion, cracking, and spalling are avoided. Understanding of the behavior of these decks on traditional girders is essential for their implementation in bridge construction.; The ability of a slab on girder bridge to resist live loads is based on the capacity of the girders, which includes the contribution of the deck for composite construction, and the load distributed to each girder. The capacity of the girder-deck system to resist loads is considered through evaluation of the failure mode (ductility) and load magnitude for a representative set of steel beam sections with a reinforced concrete deck and with a set of FRP decks with varying ultimate strains.; The load distribution among the bridge girders is evaluated by finite element analysis of four bridge geometries and through an uncoupled longitudinal-transverse analytic model. The girders for the finite element models are based upon: a set of mean parameters, an example of a single span steel girder bridge, an example of a three-span steel girder bridge, and an example of a single span prestressed concrete bridge. Each bridge is modeled with a reinforced concrete deck and with a set of FRP decks. The results of the finite element models were used to evaluate the current AASHTO LRFD formulas for load distribution in slab on girder bridges. Modifications to the formulas are presented to allow the analysis of FRP decks. The finite element results are shown to validate the uncoupled analytic model and the effects of varying bridge parameters are examined.; The evaluation of changes in load capacity and load distribution provide the tools needed to evaluate the feasibility of deck replacements using FRP. The decrease in dead load is used with the evaluation of load capacity and load distribution to determine feasible span lengths for deck replacement.