| 摘要 |
PROBLEM TO BE SOLVED: To provide a determination method of abnormal setting retardation of ordinary portland cement which can determine before using the cement whether mortar and concrete made by adding three times the amount of a retarding type AE water-reducing agent than the amount predetermined by a manufacturer induce the abnormal setting retardation or not. SOLUTION: Cement is determined acceptable when the final setting time of mortar is equal to or less than 35 hours, in tripling the amount of a LS based retarding type AE water-reducing agent added to ordinary portland cement compared to the amount predetermined by the manufacturer, and determined unacceptable when exceeding 35 hours. It is therefore determined before using the ordinary portland cement whether the cement does not induce the abnormal setting retardation without taking various measures for accelerating setting such as warming the mortar and concrete even when three times the amount of the retarding type AE water-reducing agent than the amount predetermined by the manufacturer is added. COPYRIGHT: (C)2010,JPO&INPIT
|
