Evaluation of retrofit strategies for reinforced concrete columns: a case study

The seismic performance of an existing low-rise reinforced concrete office building is evaluated in terms of its potential drift and damage levels as well as the performance curve obtained from a nonlinear pushover analysis. Different retrofit strategies for the building columns are evaluated. The retrofit schemes include increasing column strength, ductility, stiffness or a combination of these parameters. A probabilistic analysis is carried out to compare the performance of an existing frame to that of the retrofitted frames. The ground motion as well as the structure capacity are considered as random variables. The results of the analysis show that increasing the strength or strength with stiffness of reinforced concrete columns is the most appropriate technique to retrofit the structure under consideration due to the reduced values of drift and damage levels and the improved performance in the static pushover analysis.