Abstract
This paper contains the experimental considerations pertaining to continued freezing time which may influence results of accelerated freezing-and-thawing tests. To obtain on this subject, test specimens are kept in a freezing unit for different lengths of times (3, 6, 12 hr). After removal from the freezing unit, the specimens are remined in a thawing unit at 20℃ for 1 hr. These tests consist of 2 series as following, Series I Cement……Portland cement. Fine aggregate……River sand. Mix properties……1:2 (weight) water-cement ratio 50%. Series II Cement……Portland Cement. Fine aggregate……Standard sand. Mix prperties……1:2 (wheight) water-cement ratio 55%, 65%. It is conculded that the frost resistance of cement mortars is influenced by the continued freezing time, and that is approximately directly proportional to the continued freezing time.
