Plastic shrinkage cracks are fine cracks that occur on the surface of concrete before initial set. Although
plastic shrinkage cracks may not be structurally detrimental, they are not visually appealing, and will likely impact long term
durability of the concrete. Numerous studies [see ACI 305R, ACI 308R, Hover, NRMCA and Uno] have
shown that the potential for plastic shrinkage cracking to occur is a function of the ambient weather
conditions, particularly the humidity level and the wind speed, as well as the concrete mix design and
fresh concrete temperature.
The computer software application here can be used to predict the potential for plastic shrinkage cracks
to occur based on the formula discussed by Uno. Formulas for determining concrete temperature as a
function of ambient temperature are based on those discussed by Ramey and Carden. Weather data is
obtained from the U.S. National Weather Service.
The results provided by the calculator are intended for educational and informational purposes only.
Please direct inquiries about this site to firstname.lastname@example.org
ACI 305 Hot Weather Concreting, American Concrete Institute, Farmington Hills, MI, www.concrete.org.
ACI 308 Guide to Curing Concrete, American Concrete Institute, Farmington Hills, MI, www.concrete.org.
NRMCA, Concrete in Practice, CIP 5 – Plastic Shrinkage Cracking, National Ready Mixed Concrete
Association, Silver Spring, MD, www.nrmca.org.
Hover, K.C., “Evaporation of Water from Concrete Surfaces,” ACI Materials Journal, Sept-Oct 2006, Vol.
103, No. 5., pp. 384 – 389.
Ramey, G.E. and Carden, A.C., “An Assessment of Concrete Bridge Deck Evaporation Rates and Curing
Requirement Categories for Alabama,” HRC Research Project 2-13746, Feb 1998.
Uno, P. J., “Plastic Shrinkage Cracking and Evaporation Formulas,” ACI Materials Journal, July - Aug 1998,
Vol. 95, No. 4, pp. 365