Behavior of eccentrically loaded high strength concrete columns jacketed with FRP laminates

This study is an experimental investigation into the performance of high strength concrete columns subjected to uniaxial eccentricity and strengthened by glass fiber reinforced polymer fabrics (FRP). The study aims to evaluate the potential enhancement in the structural performance of seven 200 × 200 × 1050 mm columns subjected to single eccentricity strengthened by external FRP fabrics, and to investigate the effect of arrangement and amount of FRP laminates to achieve optimal enhancement. The test parameters considered are the number and arrangement of fabric layers and the value of load eccentricity. The laminates are applied in single or double layers; in partial or full wrapping in small eccentricity loading. Longitudinal laminates are provided along tension side of specimens under large eccentricity loading then overlaid by transverse FRP wraps applied partially in single layer. In the present work, test results of seven large-scale concrete columns are presented and discussed. The study has experimentally proven the efficiency of FRP laminates in enhancing the strength of uniaxially loaded HSC columns through increasing flexural capacity (by up to 23% and 59% for small and large eccentricity loaded specimens, respectively). The ductility capacity of small eccentricity loaded columns was not objectively assessed due to early termination of small eccentricity tests for safety concerns; however, a significant ductility enhancement was achieved in large eccentricity specimens strengthened by fiber reinforced polymers.