LIFETIME RELIABILITY OF FRP REINFORCED CONCRETE BRIDGE BEAMS

摘要

A recently developed approach for strengthening deteriorated concrete bridge beams consists of attaching FRP sheets to the tension sides using epoxy-based adhesives. Although previous studies have demonstrated the merits of using FRP composites over limited exposure periods, a number of issues are hampering the widespread implementation of this new technology. These issues are related to the long-term durability and reliability of FRP-based repairs under adverse environmental conditions and the lack of consistent sets of specifications for designing FRP-based repairs of bridge members. The primary objective of this paper is to develop a reliability model for studying the long-term performance of FRP composites in bridge applications. The model utilizes laboratory data on the strength of FRP repaired beams subjected to adverse environmental conditions. Strength degradation is included to account for the influence of exposure to moisture and temperature variations. The reliability analysis accounts for the uncertainties associated with predicting the load carrying capacity of FRP strengthened beams throughout the service life of the structure. The reliability procedure will lead to strengthening methods that will extend the useful lives of deteriorated bridge members and provide safety levels comparable to those required by national specifications for the design of new bridges.