高强混凝土预应力框架梁抗震性能试验研究

Experimental study on seismic performance of prestressed high-strength concrete frame beam

通过5根高强钢筋（500MPa）高强混凝土（C60）预应力框架梁与1根非预应力框架梁的低周反复加载试验，研究了换算配筋率、预应力强度比、箍筋强度等参数对预应力框架梁抗震性能的影响。试验结果表明：随着换算配筋率的增加，预应力框架梁滞回曲线逐渐捏拢，承载力下降段变陡，延性性能和耗能能力降低；当换算配筋率为2．6％-3．1％时，位移延性系数均大于3．0；当换算配筋率为3．6％时，位移延性系数为2．82，延性稍差。但若采用高强箍筋替代普通箍筋，将改善预应力框架梁的延性性能和耗能能力，此时位移延性系数为3．36；在换算配筋率等其他因素相同的情况下，预应力强度比的提高并没有明显改变梁的抗震性能；非预应力梁的延性性能及耗能能力等抗震性能均要优于预应力梁。

Through low cyclic loading tests of 5 high-strength steel （500MPa） high-strength concrete （C60） pres- tressed frame beams and a non-prestressed frame beam, the effects of converted reinforcement ratio, prestressing in- tensity ratio and stirrup strength on seismic performance of prestressed frame beams have been studied. The results show that： with the increase of the converted reinforcement ratio, pinching occur in the hysteresis loops of pres- tressed frame beams gradually, falling section of carrying capacity is steepened, ductility and energy dissipation ca- pacity are decreased ; when the converted reinforcement ratios are 2.6% to 3.1%, the displacement ductility fac- tors are greater than 3.0; when the converted reinforcement ratio is 3.6%, the displacement ductility factor is 2. 82, which shows a little lower ductility. But if use the high-strength stirrups instead of the ordinary stirrups, the displacement ductility factor would will be 3.36, which shows that the ductility and energy dissipation capacity im- prove significantly. With the same converted reinforcement ratio and the same other factors, improvement of the prestressing intensity ratio does not change seismic performance of the beams significantly. Seismic performances of non-prestressed frame beam are better than the prestressed frame beam in ductility and energy dissipation capacity.