Title: A Re-Examination of the EI Value for Slender Columns

Author(s): J.G. MacGregor, U.H. Oelhafen, and S.E. Hage

Publication: Symposium Paper

Volume: 50

Issue:

Appears on pages(s): 1-40

Keywords: building codes; columns (supports); computers; creep properties; deflections; loads (forces); modulus of elasticity; moment curvature relationships; reinforced concrete; reinforcing steels; statistical analysis; stiffness; stiffness methods

DOI: 10.14359/17464

Date: 1/1/1975

Abstract:
An incremental rate-of-creep analysis of reinforced concrete columns subjected to sustained loads is developed and used to generate data for a statistical evaluation of the stiffness, EI, of slender concrete columns subjected to short time and sustained loads. The resulting equations are more accurate than ACI Eqn. 10.7 and are as easy to use. The possibility of column failure under very high sustained loads is discussed.