【摘要】 设计了6根不同几何尺寸的中部带有短柱的高强混凝土梁式试件,进行受弯性能低周反复荷载试验,研究试件截面高度对反复荷载作用下高强混凝土梁受弯性能的影响。试件截面高度和上部纵向钢筋配筋率不同,截面长宽比、剪跨比、底部纵向钢筋配筋率和配箍率等参数相同。采用C70高强混凝土,纵向受力钢筋采用HRB400级钢筋。分析了截面高度对高强混凝土梁名义开裂弯矩、名义屈服弯矩、名义极限弯矩、位移延性、塑性转动能力、刚度退化以及耗能能力的影响。研究结果表明:截面高度对高强混凝土试件的名义开裂弯矩、名义屈服弯矩、名义极限弯矩没有明显影响;反复荷载作用下试件刚度退化明显,各试件刚度退化规律相差不大,不受截面高度影响;随着截面高度增加,位移延性系数、塑性铰区的塑性转动能力及功比指数降低,存在明显的尺寸效应。更多还原

【Abstract】 Six reinforced high-strength concrete beam-type specimens of different sizes with stubs columns in the middle were fabricated,and tested under low-cycle reversed loading to investigate the effect of depths on flexural behavior of reinforced high-strength concrete beams.The parameters of specimens varied in depths and ratios of longitudinal reinforcement on the top of cross sections,while the depth-width ratios of cross sections,shear span-todepth ratios and ratios of longitudinal reinforcement on the bottom of cross sections and stirrups were constant.C70 concrete was used to cast the specimens and HRB 400 steel bars were used as longitudinal reinforcement.The influence of beam depths on nominal cracking moment,nominal yield moment,nominal ultimate moment,displacement ductility,plastic rotation capacity,stiffness degradation and energy dissipation capacity of high-strength concrete beams were investigated.It is shown that there is no apparent size effect observed on nominal cracking moment,nominal yield moment and nominal ultimate moment of reinforced high-strength concrete beams,and that all specimens subjected to cyclic loading clearly show similar stiffness degradation which is independent of beam depths,while the displacement ductility factors,rotational capacity as well as work index of specimens decrease with increasing of depths,showing significant size effect.更多还原