Drift Capacity of Reinforced Concrete Columns

This paper introduces simple closed-form equations to estimate the lateral deformation capacity of reinforced concrete columns. The proposed simple equations are derived from an idealized lateral load-displacement behavior of a column and by taking the P-Δ effect into account. The validity of the proposed equations is examined using a large number of column tests. Estimated drift capacities are compared with the experimentally-observed drift capacities. The results show that the proposed equations provide conservative lower-bound estimates of lateral drift capacities of columns that satisfy the provisions of ACI 318-08, Chapter 21. It is also found that for slender columns supporting high axial loads, even though the detailing requirements of Chapter 21 are met, a satisfactory lateral load performance can not be expected due to pronounced secondary moments. [PUBLICATION ABSTRACT]