An analytical work was conducted on a prestressed eencrete sub − f亡ame assembled by pos 卜tensioning . Layered element analysis consider − ing bond − slip characte 【 istics of prestressing tendon was used . 皿 1e larger ratie of average effec 重 ivc prestress to compressive strength of conc τe重 e in the section and the smaller ratio ofaverage effective prestress to O2 % offset yield stress of 壮he tendon were assigned , the larger difference of fiexural strength betWeen the cases with and withou 重consideration of bond −sHp was obse 四 ed , Fu τthe ore , the flexural behavio 【of 重 he member was significauUy influenced by the bond yield stress, while the effect of the bond stiffness was hardly found .