Abstract
This paper discribes the effects of the rate of cooling factors on the results of freezing and thawing tests. The experimental objects are nine river sand mortars, one standard mortars and three cement pastes, and the rate of cooling factors have six levels from 0.09 to 0.41℃/min. The results obtained are summarized as follows, (1) Resistance of frost mortars are affected greatly by the rate of cooling. (2) On the frost action of mortars, the most effective rate of cooling has a range from 0.15 to 0.2℃/min. (3) On the frost action of cement paste, the smaller the rate of cooling, the larger the frost damage. (4) The variable supercooling of water hypothesis. "The more rapid the freezing speed, the more the supercooling of water". Phenomena of the frost damage of mortar and cement paste specimens are explained by the above hypothesis.
