Title: Simplified Method to Account for Effects of Creep and Shrinkage in Structural Analysis

Author(s): D. J. Carreira, M. Daye, and L. R. Greening

Publication: Symposium Paper

Volume: 194

Issue:

Appears on pages(s): 237-260

Keywords: age-adjusted modulus; creep; creep and shrink-age strains; curvature; deflections; effective modulus; re-laxation of stresses; shrinkage; thermal

DOI: 10.14359/9896

Date: 5/1/2000

Abstract:
This paper presents a simplified, comprehensive and rational method to account for the effects of creep and shrinkage in reinforced concrete struc-tures. The analysis of the effects of creep and shrinkage on reinforced and prestressed concrete structure is a multifaceted problem. In general, creep and shrinkage are not common knowledge and concern of most structural engineers. The procedure includes (a) a simplified estimation of the creep and shrinkage strains in plain concrete, (b) the analysis of the effect of creep on reinforced concrete structures using the age-adjusted modulus of elasticity, (c) the analysis of the effects of shrinkage using an equivalent temperature drop. (d) the relaxation of stresses, internal forces and moments from imposed deformations, (e) the analysis of thermal changes on structures. An introductory approach of analysis of concrete structures creep and shrinkage should be satisfactory for structures not critically sensitive to the effects of creep and shrinkage. For structures sensitive to these effects, such as tall buildings or record span bridges, a more advanced analysis will be necessary, which is beyond the scope of this paper. The presented method includes most of the aspects affecting the effects of creep and shrinkage on concrete struc-tures, and it may be coupled with more advanced treatment of specifically related subjects.