Investigation of frost resistance of mortar and concrete
Buck, Alan D.
Technical reportAbstract: Specimens from 12 mortar mixtures and one concrete mixture were tested for frost resistance by accelerated freezing-and-thawing tests and by dilation, for compressive strength, for freezable water (FW), and for weight changes after each of eight different treatments. One variable of treatment was age of continuous moist curing; the other was age together with cyclic fluctuation of water pressure to simulate the conditions that would affect concrete at a low level in the Eisenhower Lock of the St. Lawrence Seaway. The results of these tests indicated: a. The cyclic pressure treatment did not cause critical saturation to develop in most of the test specimens, including those most like the concrete in the Eisenhower Lock. Therefore, changing water levels presumably would not have developed critical saturation of the concrete in the lock. b. The concrete mixture which simulated the concrete in Eisenhower Lock with the large aggregate removed was frost resistant. c. The usual relationships between frost resistance and variables of age, compressive strength, water cement (w/c) ratio, and air content were apparent. d. The amount of air needed to obtain maximum frost resistance of the mortars increased with increasing w/c ratio to a maximum of about 9 percent air for a w/c ratio of 0.8 by weight. e. The data indicated that FW is not a useful index of frost resistance for air-entrained mortar or concrete mixtures. f. Frost resistance increases with increasing age as the w/c ratio increases. g. Dilation testing provides a sensitive measure of the frost resistance of mortar and concrete. Dilation testing could be a useful adjunct to accelerated freezing-and-thawing tests of concrete to provide more information on the relation of environmental influences and frost resistance.
Concrete Laboratory (U.S.)Engineer Research and Development Center (U.S.)
Concrete tests; Eisenhower Lock; Frost resistant concrete; Mortars
Technical report (U.S. Army Engineer Waterways Experiment Station) ; C-76-4.
Approved for public release; distribution is unlimited.