无粘结部分预应力高强混凝土梁变形计算

Calculation of deformation for unbonded partially prestressed concrete (PPC) beams with high strength concrete

通过２６根无粘结部分预应力高强混凝土梁试验，研究了影响无粘结梁变形的主要因素：预应力筋配筋率、非预应力筋配筋率、跨高比、荷载作用方式．将预应力筋和非预应力筋对无粘结梁跨中最大挠度的影响，用无粘结配筋指标和综合配筋指标之比η和换算配筋率αｐρ这两个参数来反映，并且采用与国内有关规范相一致的直接双直线法，在单调荷载作用下无粘结部分预应力高强混凝土梁变形计算基础上，建立了任意荷载作用下的无粘结部分预应力高强混凝土梁变形计算公式．

Based on the experimental results of 26 unbonded partially prestressed concrete beams with high strength concrete, the main factors which affect the deformation of unbonded beams is studied, including prestressed and nonprestressed reinforcement and ratio of beam span to depth and types of loading. The effect of prestressed and nonprestressed reinforcement upon maximum deflection in the mid span of unbonded beams is reflected with the ratio of unbonded reinforcement index to composite method in accordance with the present codes, the deformation formula of unbonded PPC beams with high strength concrete under arbitrary loading is obtained based on that under monotonic loading .The calculating results agree well with experimental results.