Creep stability and buckling strength of concrete columns

Abstract

Summary A solution is given for the long-term deflexions of a reinforced concrete column with an initial curvature according to a general theory of linear creep. This is used to produce solutions: (1) according to the Arutyunyan-Maslov theory (using an incomplete gamma function); (2) according to the approximate Dischinger-Whitney law; (3) by the use of an effective deformation modulus. It is shown that, whilst critical long-term loads may be calculated, these are very sensitive to inaccuracies in the creep theory and that it is more convenient to consider the long-term buckling strength of a column. A practical method of analysis is presented in which the long-term buckling strength is assessed by calculating the short-term buckling strength but using a reduced elastic modulus. Graphs are presented to aid analysis.