Capacity of RC Columns Strengthened with RC Jackets

Reinforced concrete (RC) jacketing of RC columns is used to increase the load-carrying capacity due to insufficient strength and it improves ductility behavior of the RC columns after jacketing. In this study, strength capacity of the RC columns strengthened with RC jackets was studied.

To achieve the goal of this study, the strength capacity of the columns was computed based on expressions given by researchers and by adopting the existing codes. For the expressions by researcher, prediction models of Mander et al. (1988), and Sheikh and Uzumeri (1982) were used. For existing codes, ACI318M-19, Eurocode 2, BS8110, and IS456:2000 was adopted. First, results obtained from expressions and existing codes were compared with test results by Takeuti et al. (2008) and Ugur Ersoy (1991). Then, parametric studies were carried out in this study by varying stirrup spacings of jacketing, jacket thicknesses, concrete compressive strength of the existing columns, and concrete compressive strength of jackets.

The results from this study demonstrated that for the expressions by researchers and for the existing codes the predicted strength capacity of RC columns after jacketing was about 10% and 56% below the test results, respectively. From the parametric study, it showed that the stirrup spacing, the jacket thickness, the strength of concrete of existing columns and jackets significantly influenced the strength capacity. This study could conclude that both the expressions by researchers (Mander et al. (1988), and Sheikh and Uzumeri (1982)) and the existing codes (ACI318M-19, Eurocode 2, BS8110, and IS456:2000) could be suitable for predicting the strength capacity of RC columns strengthened with RC jackets.