Title: Shrinkage and Creep Behavior of Concrete Made with PFA Coarse Aggregates

Author(s): R. N. Swamy and G. H. Lambert

Publication: Symposium Paper

Volume: 91

Issue:

Appears on pages(s): 145-170

Keywords: coarse aggregates; compressive strength; concretes; creep properties; deformation; density (mass/volume); fly ash; lightweight aggregate concretes; lightweight aggregates; shrinkage.

DOI: 10.14359/10068

Date: 2/1/1986

Abstract:
This paper presents comprehensive data on the shrinkage and creep behavior of concrete made with PFA coarse aggregates and sand and having 28 day strengths of 30-60 N/mm'. Continuously moist cured concrete showed expansion of about 16-21% of the 500 day shrinkage. At one month some 33% of the 500 day shrinkage and 50% of the one year creep occurred regardless of the concrete strength and exposure condition. The shrinkage took about one year to stabilise, whereas creep mostly stabilised in about six months. When unloaded, the fly ash aggregate concrete was able to recover all of its initial elastic strain on loading, but creep recovery was limited to about 10%. The hyperbolic relation can be used to predict satisfactorily both shrinkage and creep, and these values can be used to evaluate the shrinkage and creep effects on reinforced and prestressed members. The paper points out that the shrinkage and creep of fly ash aggregate concrete compare favourably with those of dense concrete.