الفهرس 
ABSTRACTOnly 14 pages are availabe for public view
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Abstract
Various existing RC buildings were designed according to earlier code provisions or were subjected to damage caused by previous earthquakes. Seismic strengthening of these buildings with buckling-restrained braces (BRBs) represents a practical and economic upgrading solution nowadays. Steel BRBs have a considerable ability to upgrade the strength, stiffness, and energy absorbing capacity of RC buildings. However, they are prone to producing high levels of residual drifts after strong ground motions. This may make buildings appear unsafe to residents and may require building demolition. Recently, shape memory alloy (SMA) BRBs have received substantial interest because of their promising potential in controlling residual drifts following earthquake events. This study evaluates the seismic strengthening of 3- and 6-storey RC buildings using steel, SMA, and hybrid SMA-steel BRBs. The buildings are subjected to static pushover loading and a suite of earthquake records. The peak and residual drifts along with the brace ductility ratios are used as the basis for the performance evaluation. The results obtained indicate that, in comparison with steel BRBs, the SMA and hybrid SMA-steel BRBs are more effective in controlling the residual drifts of the upgraded RC frames. The results obtained in this study indicate that strengthening of RC buildings with hybrid SMA-steel BRBs is an efficient and economic technique to upgrade the seismic capacity of existing RC frames as it significantly increases the base shear capacity of the existing RC buildings while maintaining minimal levels of residual drifts.