Title: Influence of Aggregate Restraint on the Shrinkage of Concrete

Author(s): D. W. Hobbs

Publication: Journal Proceedings

Volume: 71

Issue: 9

Appears on pages(s): 445-450

Keywords: aggregate gradation; aggregates; bulk density; cement pastes; lightweight aggregates; modulus of elasticity; shrinkage; water content.

DOI: 10.14359/7089

Date: 9/1/1974

Abstract:
A comparison is made of the various models which have been proposed to predict the dependence of concrete shrinkage upon the properties of its constituents and the aggregate volume concentration. The predictions of one of these models, the Cement and Concrete Association model, are compared in a general way with the observed shrinkagebehavior of concrete. It is shown that the shrinkage of normal aggregate concretes is dependent primarily on only three parameters-the paste shrinkage, the aggregate shrink-age, and the aggregate volume concentration. The observed dependence of concrete shrinkage upon original water content by weight, Young’s modulus of the concrete and aggregate grading, for specimens of the same water-cement ratio, is shown to follow directly from the simple depen-dence of concrete shrinkage upon aggregate volume concen-tration. [Author]