Quantifying the Effects of Seismic Loading History on the Collapse Behavior of Concrete Columns

The current assessment methods to retrofit vulnerable concrete buildings in the US [ASCE 41-17, ACI 369.1-19] produce relatively conservative deformation capacities at the loss of lateral and axial strengths. Such conservatism hinders region-wide efforts to retrofit deficient buildings due to high costs. To improve the accuracy and reliability of structural assessment, continuum finite element models were calibrated to experimental tests for over twenty columns. Calibrated column models were then subjected to a series of loading protocols, including monotonic pushover and non-symmetric ratcheting protocols. The effects of the lateral loading protocols on damage progression, strength, and deformation capacities are discussed in these columns.