Published works

Displacement-based design of reinforced-concrete (RC) columns requires reliable estimation of the drift capacity beyond the elastic range. Although many post-peak drift models exist for normal-strength RC (NSRC) columns, very limited work has been done in this area on high-strength RC (HSRC) columns. This paper evaluates the capability of existing drift models to predict post-peak drift capacity of both NSRC and HSRC columns. A comparative study is conducted using a comprehensive database of 190 RC columns (79 HSRC and 111 NSRC) from past experimental studies. The results of the comparative study indicate that most of the existing drift models overestimate post-peak drift capacity of HSRC columns, primarily because the influence of concrete strength has been ignored. This paper also proposes a unified set of empirical drift models that have a unique ability to predict post-peak drift capacity of lightly to moderately reinforced NSRC as well as HSRC columns. The new models can serve as tools for structural design engineers to estimate drift capacity of RC columns at an early design stage. Moreover, the models can assess the drift performance of RC columns in existing buildings and hence can also aid in decision-making regarding the need for retrofitting.