Statistical Characterization of Reinforced Concrete Beams Strengthened with FRP Sheets

Abstract

This paper presents a comprehensive overview of the characteristics of reinforced concrete beams strengthened with fiber-reinforced polymer (FRP) sheets. A large database consisting of 230 test beams is constructed and analyzed using advanced statistical approaches such as multivariate analysis of variance, parameter estimation analysis, and discriminant analysis. Pearson correlation is conducted to identify linear dependency between test parameters. Parameters influencing debonding of the FRP are determined at a confidence level of 95%: concrete strength, steel reinforcement ratio, FRP thickness, and beam geometry. Transition of failure modes between FRP debonding and cover delamination is affected by FRP rupture strain and a steel reinforcement ratio. Discriminant functions are developed to infer the failure mode of FRP-strengthened beams. Existing design proposals for FRP debonding are evaluated using the test data. A new statistics-oriented equation is proposed to predict the effective strain of FRP-concrete interface on the basis of Monte-Carlo simulations associated with random sampling of contributing parameters.