Title: Influence of Drying on Strength of Concrete Specimens

Author(s): C. D. Johnston and E. H. Sidwell

Publication: Journal Proceedings

Volume: 66

Issue: 9

Appears on pages(s): 748-755

Keywords: cracking (fracturing) ; drying; moisture content;plain concrete; shrinkage; specimens;tensile strength.

DOI: 10.14359/7399

Date: 9/1/1969

Abstract:
Observed reductions in the 28 day strength of plain concrete specimens, dried in air before testing, are shown to agree with theoretical values calculated using a reduced effective cross-sectional area, which results when moisture diffusion from a specimen causes varying degrees of shrinkage across its cross section, to such an extent that cracking penetrates from the surface inwards. The results show that this reduction in tensile strength cannot exceed one third of the strength of the saturated concrete, and that it is independent of specimen size.