A.5~7 B.3~4 C.9~11 D.15~17
A.張拉應(yīng)力值 B.預(yù)應(yīng)力筋的伸長(zhǎng)率 C.總張拉力 D.張拉應(yīng)力及預(yù)應(yīng)力筋伸長(zhǎng)值雙控
A.前者高 B.前者低 C.兩者相等 D.沒(méi)有規(guī)律