某一外加劑進行檢測,拌和25L,所測數(shù)據(jù)如下: 則該外加劑的減水率為()。
A.21.5% B.21.9% C.22.2% D.試驗結(jié)果無效,應重做
A.1.5min B.2min C.2.5min D.3min
A.50Ns±10N/s B.80Ns±10N/s C.2400N/s±200N/s D.2500N/s±250N/s