高强钢筋约束混凝土矩形柱的抗震性能试验研究

目的 研究通过配置高强度等级横向钢筋，增强高强混凝土矩形柱的承载能力和变形性能．方法 通过6根配有1420级预应力钢棒（简称PC钢棒）作高强钢筋，混凝土强度等级分别为C60和C90的高强混凝土柱在低周反复荷载下的模型试验，研究了轴压比、箍筋（包括含箍特征值、箍筋间距、箍筋种类）、纵筋和混凝土强度等级等参数对其抗震性能的影响．结果 明确了其破坏机理和强度及变形的主要影响参数．在试验的基础上，提出了配置PC钢棒作箍筋和部分作纵筋的高强混凝土柱的位移延性比与轴压比和含箍特征值关系的经验公式，计算得出的试件位移延性比的计算值与实测值吻合较好．结论 在高强混凝土柱中配置高强度箍筋和部分配置高强度纵筋，并保证一定的构造措施，可有效提高柱的延性，增强抗震能力。

Seismic Performances of Square HSC Columns Confined with High-Strength PC Rebar

This study focused on increasing the seismic performances of rectangular high strength concrete(HSC) columns by using ultra strength rebar as transverse reinforcements in order to enhance both seismic bearing and deformation capacity during earthquake ground motion.6 model tests,in which ultra strength rebar with the yield strength of 1420 MPa and high strength concrete with C60 and C90 grade are used,were carried out in the lab under the low circle repeated loading.The factors influenced the seismic performances of this kind of column were researched experimentally by using variable parameters such as axial compression ratios,stirrup reinforcements(index,space and type),and grades of longitudinal rebar and concrete.The failure mechanisms were experimentally clarified and the main parameters for strength and deformation of the columns were also determined empirically.An empirical formula represented the relationship of the displacement ductility,the compressive ratio and index of stirrup was derived numerically on the basis of the test data.The formula could be used to calculate the ductility of the column.The results of the test study showed that both bearing capacity and deformation ductility of the columns could be increased effectively by using ultra strength rebar as transverse reinforcement,confined HSC,and effective construction in details.