Recycled Aggregate Concrete in FRP-confined columns: A review of experimental results

This paper presents a review of experimental tests performed for the characterization of the mechanical behavior of FRP-concrete members realized employing Recycled Aggregate Concrete (RAC). First, with the aim to define confinement effects on RAC, the mechanical behaviors of RAC under triaxial compression is discussed, highlighting the governing variables and their influence on the mechanical response. Different variables such as Recycled Concrete Aggregate (RCA) content, pre-wetting, confinement level, concrete age and RCA source are analyzed and their implication on the main mechanical properties is discussed. Then, the static and cyclic behavior of FRP-confined RAC members is reviewed. Considering the static behavior, columns under concentric compression and eccentric compression are analyzed. Finally, the limited number of results available from the literature are employed to derive a prediction model for the strength of multi-axial stressed and confined RAC by considering the RCA content as the main governing variable. The need for further research is pointed out at the end of the paper.