ANALYSIS OF FRP WEB CORE BRIDGE DECK STRUCTURE

Abstract

Fiber reinforced polymer (FRP) composites have been used in other industries for years, but their use in highway bridge decks is relatively new. Many RCC bridges are showing signs of distress due to corrosion of the reinforcements much before there design life span. Use of Fiber Reinforced Polymer (FRP) Bridge is increasing rapidly all over the world due its many advantages over the conventional materials. Over the past several years, however, many short span bridges have been built or rehabilitated with FRP decks in the United States of America and many other developed countries. Since all of these were designed and constructed without the benefit of nationally accepted standards, there are varied lessons to learn from these projects. Concrete bridge decks are subjected to severe environmental conditions and heavy traffic loads. They sometimes account for major portion of a bridge structures dead load. A laminated composite FRP deck weighs approximately 80% less than a concrete deck. Reduction in dead load increases the allowable live load capacity of the bridge without significant repair to the existing super structure and sub-structure; and thus lengthening its service life. The high strength, high fatigue resistance, low density and excellent corrosion resistance of composite panels are desirable characteristics for bridge applications especially bridge decks. Being a thin walled structure, their behaviour is governed by stability criteria. In this dissertation work a FRP bridge deck configuration having a sandwich structure with two way web core and face skins as well as sandwich structure with foam core are investigated. These configurations dramatically reduce the weight of the deck and also reduce the chances of possible modes of failure due to the design loads. In the present study, initially, the problems of FRP web core sandwich bridge deck subjected to uniform pressure is analysed by developing a Finite Element Model of the FRP web core bridge deck by using ABAQUS first and the results were compared with the work done by previous researchers. In all the cases the results obtained by the present FE model compared very 1 well. As such the Finite Element Model based on ABAQUS is used to generate many new results for FRP bridge deck subjected to Indian loading standards (IRC). A parametric study has been carried out for the FRP web core bridge deck as well as FRP foam core bridge deck subjected to IRC Class AA loading keeping in view the design requirements for their feasibility and safety with the serviceability criteria of deflection being also satisfied. Decks of various spans, web configurations and depth are analysed to arrive at an optimum design by calculating deflections and stresses at important locations. The present numerical study should be quite useful for further research and implementation of FRP web core and foam core decks in India in near future.