Fragility functions for reinforced concrete columns incorporating recycled aggregates

•The process of modelling fragilities of flexure-critical RAC columns is introduced.•The data is compiled from a broad family of RAC columns.•Fragility curves are constructed for three damage states.•The effect of parameters on drift demand and damage is determined.•Seismic performance of RAC columns is discussed in terms of ductility capacity.•The fragilities of RAC and NAC columns are compared. Using recycled aggregates in the production of structural members is a relatively new application that has the potential to become a mainstream practice with effective green policies. Therefore, performance-based seismic assessment of structures constructed using recycled aggregates gains importance. Fragility curves, cumulative distribution functions that represent the probability of being in or exceeding a threshold for a selected engineering demand parameter, can be used in risk evaluation of these structures. In this study, fragility functions are generated by compiling the data of reinforced concrete columns incorporating recycled concrete aggregate available in the literature. The data is first evaluated through physical damage states, and three different damage states, namely Damage State 1, Damage State 2 and Damage State 3, are defined. Each damage state is then mapped to a certain repair category (cosmetic repair, structural repair or structural enhancement) so that damage can be defined in terms of economic loss, which would provide a road map in the disaster management decision making process. Drift ratio is selected as the engineering demand parameter since generally displacement demand is taken into account in the evaluation of seismic performance of structures. Based on the results of the statistical analysis, the median drift ratio values of 0.30%, 1.21%, and 3.25%, and logarithmic standard deviations of 0.95, 0.42, and 0.45 are determined for Damage State 1, Damage State 2, and Damage State 3, respectively, for columns incorporating recycled concrete aggregates. Furthermore, the effect of parameters on the relationship between drift demand and damage is investigated. In addition, seismic performances of the columns are discussed in terms of their ductility capacity. It is also shown that the ductility limit defined according to Paulay and Priestley (1992), and UBC (1997) for the reinforced concrete columns made of natural aggregate concrete is valid also for the columns made of recycled aggregate concrete. Besides, fragility functions are also gen