BEHAVIOUR OF FRP WRAPPED SQUARE RC COLUMNS UNDER DIFFERENT LOADING CONDITIONS Muhammad NS HADI Assoc Professor University of Wollongong School of Civil, Mining and Env Eng, Wollongong NSW 2522 Australia mhadi@uow.edu.au Ida BR WIDIARSA Mr University of Udayana, Bali 80361, Indonesia, currently a PhD Scholar at the School of Civil, Mining and Env Engineering, University of Wollongong, Wollongong, NSW 2522, Australia Affiliation ibrw943@uow.edu.au Abstract This paper presents results of testing square RC columns wrapped with FRP. The influence of the number of FRP layers and the magnitude of eccentricity were studied through experimental. A total of 16 short square reinforced concrete columns wrapped with CFRP were investigated. The columns had the dimensions 200 mm x 200 mm x 800 mm and a round corner with radius of 34 mm. 12 columns were tested under compressive loading and four columns were tested under flexural loading. Based on the number of CFRP layers, the columns were grouped into four: no-layer (unwrapped), wrapped with one layer, wrapped with three layers, and wrapped with two layers after the application of one vertical layer of CFRP straps. From each group, one column was tested under concentric loading, one column was tested under 25 mm eccentric loading, one column was tested under 50 mm eccentric loading and the last column was tested under flexure loading. The results have shown that wrapping column with CFRP composite increase the capacity and ductility of the column. Keywords: CFRP, square reinforced concrete columns, eccentric loading, ductility. 1. Introduction Retrofitting or strengthening reinforced concrete columns by using FRP composites is preferred than by using other materials like steel due to its high strength-to-weight ratio and high corrosion resistance. Several investigations on FRP retrofitted or strengthened concrete columns have been undertaken for many years. Most of these studies investigated the behaviour of columns under concentric loads [1-3] and only a few studies presented investigation of columns under eccentric loads. Consideration of applying eccentric loads was undertaken by researchers due to the reality that most columns in the field are loaded under a combination of axial compression load and bending moment. Consideration of eccentric loads being applied on FRP strengthened concrete columns has been done by a few researchers. Other than the magnitude of eccentricities, the shape of column cross section is an important factor that influences the confining behaviour of the FRP strengthened concrete columns. Some investigations on FRP strengthened concrete columns under eccentric loads have been done by researchers and mostly concerned on columns having a circular cross section [4-9]. Only a few investigations have studied concrete columns with square or rectangular cross sections [10,11]. Moreover, most concrete columns in the Page 1 of 8