夏春红  王玉起
    （天津大学 300072）

[提要]  通过对国内外60根试验梁的分析，得出计算无粘结筋极限应力的公式，具有较高的精度。由该公式可知，非预应力筋对无粘结筋极限应力的影响随配筋强度比的增加发生改变。
[关键词]  无粘结筋 极限应力 预应力筋 非预应力筋 配筋指标 配筋强度比

Based on the analyses of sixty experimental unbonded partially prestressed concrete beams at home and abroad, a formula for evaluating the ultimate stress in unbonded tendons, which has high accuracy, is proposed. The calculation results show the effect of nonprestressed steel on the ultimate stress of unbonded tendons changes with the increase of steel index ratio.
Keywords: ultimate stress; unbonded tendons; prestressing; nonprestressing; steel index ratio