BEHAVIOR OF BIAXIALLY AND UNIAXIALLY LOADED SHORT HIGH STRENGTH CONCRETE COLUMNS STRENGTHENED USING FIBER REINFORCED POLYMER LAMINATES

Abstract

Nowadays, the use of fiber reinforced polymers (FRP) in strengthening and retrofitting reinforced concrete structures has spread worldwide. In spite of that, there is some lack of knowledge regarding the behavior of high strength concrete columns (HSC) strengthened using FRP laminates, especially those subjected to uniaxial and biaxial bending morrierits accompanied with axial loading. The present' study introduces results of an intensive experimental investigation into the performance and behavior of biaxially and uniaxially loaded HSC square short columns strengthened with externally applied FRP laminates. Nineteen columns were tested through two phases: The first phase included te ting of 12 HSC and normal strength concrete columns under biaxial loading, while the second one included testing 7 HSC uniaxially loaded columns. Test phases reflected the main variables considered in this study which were: the number, arrangement and type of FRP laminates, value of load eccentricity, concrete compressive strength and steel tie volumetric content. The results of this investigation showed the potential influence of FRP strengthening regarding axial load and flexural capacities as well as•ductility of the tested columns.