A.0.25~0.60% B.0.25~0.8% C.0.5~0.8% D.0.35~0.6%
A.fcu,k=25Mpa B.28Mpa≤fcu,k≤30Mpa C.25Mpa≤fcu,k<28Mpa D.25Mpa≤fcu,k<30Mpa