A new cement for cold weather construction
Hoff, G. C. (George C.)
Miscellaneous paperAbstract: Some of the principal problems associated with winter concreting are the protection of the freshly mixed concrete from freezing and the provision of a curing environment conducive to the development of sufficient strength in the concrete so that subsequent freezing and thawing will not damage the concrete. If the concrete is kept sufficiently warm (>32 F) so that it does not freeze when made and placed, it will continue to develop strength with the rate of strength gain depending on the temperature at which it is cured. A recently developed cement, culled regulated-set cement, is capable of developing very high strengths at ages of 1 to 2 hours. This strength development is accompanied by a substantial release of internal heat during the hydration of the cement. The combination of these two characteristics provides a potential for the elimination of the elaborate and expensive curing procedures now used for cold weather concreting. This potential was examined both in the laboratory and field. The heat development in 3-, 6-, and 12-in.-thick slabs exposed at 15 F immediately after casting peaked in 1 to 2 hours at 46.5, 58, and 69 F, respectively, and remained above freezing long enough to gain considerable strength. Specimens protected 1 hour before exposure exhibited almost as much strength at 28 days age as specimens cured at 70 + 3 F the full time. Other factors such as concrete temperature at placing and construction procedures were also evaluated. The use of the regulated-set cement in cold weather situations should reduce the cost of the concrete construction and extend the construction season when cold weather sets in.
Concrete Laboratory (U.S.)Engineer Research and Development Center (U.S.)
Cement; Cold weather construction; Concrete curing; Freeze-thaw durability; Regulated-set cements
Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; C-76-11.
Approved for public release; distribution is unlimited.