Concrete: Cracking tendency – exposure to drying during the first 24 hours (NT BUILD 433)

Abstract

SCOPE

This Nordtest method is intended for the determination of the cracking tendency of concrete at early ages. The test is performed on 3 ring shaped specimens exposed to an air stream of defined velocity, temperature and relative humidity the first 20-24 hours after casting. The crack development is judged quantitatively at the end of this period.

FIELD OF APPLICATION

This method can be used for an evaluation of the cracking tendency of different types of concrete exposed to early drying. The method can also be applied in order to evaluate the effect of various parameters, such as different constituents, concrete composition, fibre additions and curing membranes. The method gives information on the relative cracking tendency, but cannot predict the extent of cracking which will in practice occur under the prevailing field conditions.