Title: Crazing in Concrete and the Growth of Hair Cracks Into Structural Cracks

Author(s): Alfred H. White, Vilhelm A. Aagaard, and Axel O.L. Christensen

Publication: Journal Proceedings

Volume: 24

Issue: 2

Appears on pages(s): 190-201

Keywords: none

DOI: 10.14359/15383

Date: 2/1/1928

Abstract:
The fine cracks which occur on the surface of concrete and especially of mortar rich in Portland cement are frequently called hair cracks and the phenomenon is often alluded to as crazing. A crack may result from a blow or other mechanical cause, but the most frequent cause is the unequal expansion and contraction of the surface and the main body of the material. This unbalanced condition may be caused by heat, and temperature changes are undoubtedly a contributing cause, but the chief cause of both the initial formation and the growth of these cracks lies in variation in the moisture content of the hydrated cement.