An empirical model for predicting the mechanical properties of FRP-confined concrete

The mechanism of confining concrete using FRP materials was studied experimentally in numerous works, whereas several models were proposed for the prediction of the mechanical properties of FRP-confined concrete. The first part of this paper is devoted to systematic assessment of the performance of some of the existing models. Since this assessment proves that there is room for more accurate prediction of both strength and ultimate strain of confined concrete, the second part of the paper deals with derivation of an empirical model valid for both circular and prismatic elements. The model adopted by Eurocode 2 for concrete confined by means of hoops or spirals was used as a basis. The validity of the proposed model is checked against experimental results provided by 84 experimental programs (including 785 cylindrical specimens and 289 prismatic specimens). The model proposed in this paper is in good agreement with the experimental results. A set of partial safety factors is proposed for the derivation of design values for strength and ultimate strain of FRP-confined concrete.