Numerical and Experimental Investigation on Eccentric Loading Behavior of RC Columns Strengthened with SCC Filled Square Steel Tubes

Self-compacting Concrete Filled Square steel Tubes (SCFST) is used to strengthen square RC columns. In order to investigate the eccentric loading behavior of the strengthened columns, a generic fiber element model is proposed. The ultimate strengths and the complete load-deflection response at the mid-height of the strengthened columns are predicted by the model in the aid of computational procedure. To verify the accuracy of the computational results, related experiments have been performed. The obtained experimental results were then compared with the computational results. After finding close agreement between them, the effects of extensive experimental parameters on the behavior of strengthened columns are investigated, including tube wall thickness, concrete compressive strength and initial eccentricity. Furthermore, a simple design formula based on the verified model is proposed to calculate the ultimate strength of eccentrically compressed strengthened columns. The calculation results agree well with the experimental results.