Procedure for the Statistical Determination of the Design FRP-Confined Concrete Strength

Worldwide research has now reached a level of integration where an effort towards the harmonization of procedures is absolutely needed. Such harmonization may regard, for example, the various steps that lead to the definition of capacity models to be included in design codes, specifically: definition of the test setup, quantities to be measured, identification of the basic variables influencing the phenomenon, distinction between average values and other fractiles, disaggregation of the model in different parts accounting for me-chanics, fine-tuning and randomnesses, and, finally, assessment of the model against the experimental results. Test results and ensuing model developed according to this procedure would naturally lend themselves to be easily shared among the scientific community and would facilitate the task of calibrating the partial coeffi-cients, with the ambitious aim of attaining a uniform reliability level among all capacity equations. This paper, based on previous author works, proposes the application of a procedure for the development of capacity design equations to the capacity model of concrete confined with FRP. The procedure has been applied, with some improving, to a new capacity model proposal and to the one included in the Italian Instructions CNR DT 200–2004. The comparison has the aim of evaluating the uncertainties of the assumed model (both of the me-chanical model and of the basic variables) to obtain a constant level of structural reliability and to outline the implication that a not very well calibrated equation could have in the definition of the characteristic value.