Finite element analysis of reinforced concrete columns confined with composite materials

The use of composite materials in civil engineering, especially for the str engthening and retrofitting of existing structural elements, is a domain th at is growing at a fast pace. The rapid expansion of the structural repair business has already provided numerous opportunities to demonstrate the pot ential of these materials. However, it has also indicated the need to bette r understand their properties and the necessity of reliable models to predi ct the behaviour of repaired structures and the long-term response of those materials considering the effects of freeze and thaw or UV exposure. This article presents a model to predict the ultimate load of a reinforced concr ete column confined with composite materials without post-peak response. In addition to the ultimate load, the model identifies the evolution of stres ses and strains in the column during the entire loading process. Calculatio ns are made under constant axial and incremental lateral load. The finite e lement calculations presented here are based on the use of bar elements. Th ese are numerically integrated, considering the appropriate behaviour of th e materials in the section of the column. Special attention was paid to the development of a stress-strain relationship representative of the actual b ehaviour of concrete confined with composite materials.