A.2~4MPa B.4~6MPa C.6~12MPa D.15MPa
A.混凝土構(gòu)件本身 B.預(yù)應(yīng)力張拉臺座 C.張拉千斤頂 D.后張法預(yù)應(yīng)力專用固定設(shè)備
A.70% B.80% C.85% D.90%