A.28d B.30d C.14d D.3d
A.減水劑 B.引氣劑 C.早強(qiáng)劑 D.膨脹劑
A.fcu,0=fcu,k+1.645δ B.fcu,0=fcu,k+1.56δ C.fcu,0=fcu,k+1.85δ D.fcu,0=fcu,k+1.45δ