预应力型钢超高强混凝土梁抗弯延性试验

为研究预应力型钢超高强混凝土梁的抗弯延性性能,进行了15根预应力型钢超高强混凝土梁和3根预应力超高强混凝土梁在静力荷载作用下的受弯性能试验.结果表明:内置型钢提高了试验梁承载力的同时,提高了试验梁峰值荷载后的持载能力;试件的位移延性系数随着有效预加力、型钢含钢率、普通纵筋和预应力筋配筋率的增大而降低,随着钢绞线和型钢在截面内位置高度的降低而降低.分析了考虑截面整体配筋情况的综合配筋指数ωc与位移延性系数的关系,通过数据线性回归,给出以综合配筋指数ωc作为单一变量的位移延性系数简化计算公式.

Flexural ductility of prestressed steel reinforced ultra-high strength concrete beams

Fifteen specimens of the prestressed steel reinforced ultra-high strength concrete beams and three specimens of the prestressed ultra-high strength concrete beams were tested to investigate the flexural ductility of specimens. The test results indicated that: the encased structure steel increased the bearing capacity of specimens, and enhanced the ability of sustaining load after peak load of the specimens. The increase of effective pre-stretching stress, reinforcement ratio of structure steel, reinforcement ratio of ordinary longitudinal bar, and reinforcement ratio of prestressed tendon leaded to the decrease of displacement ductility factor, the decrease of depth of prestressed tendon and structure steel leaded to the decrease of displacement ductility factor. The effect of complex reinforcement index considering of reinforcement on displacement ductility factor were studied. By linear regression of test dates, the simplified calculation formula of displacement ductility factor was obtained, and complex reinforcement index was a single variable in this formula.