New Model for Evaluation of FRP Debonding Strain for Russian Design Code

The most probable failure mode of FRP-strengthened RC beams is an intermediate crack-induced debonding. Over the last 13 years, researchers developed several methods for calculation strain corresponding to delamination of FRP. A significant number and diversity of existing foreign and domestic methods make the design complex process. The aim of this study was to propose a simple method for calculating FRP debonding strains, based on the best international achievements and adapted for use in Russia. To achieve this goal, the authors performed a review and reliability assessment of existing foreign and domestic meth-ods. Reliability assessment is made by comparing the calculated and experimental data. Experimental data were collected from the existing literature. After reliability assessment, the most simple and accurate method was selected among the considered. On the basis of the chosen method, the authors proposed a formula for calculating the design value and characteristic value strain corresponding to delamination of FRP. The results of calculations by the authors’ formula are more economical than the original method and have the required reliability for these variables. The proposed method is recommended for use in the design of flexural FRP-strengthened RC beams in Russia