高强钢筋超高性能混凝土柱抗震性能研究

Experimental study on seismic behavior of high strength reinforced ultra high performance concrete columns

为研究高强钢筋超高性能混凝土柱抗震性能,对4根配置630MPa高强钢筋的超高性能混凝土柱进行低周往复荷载试验。研究轴压比、箍筋间距和纵筋配筋率对试验柱的破坏特征、受力性能、滞回特性以及其耗能性能等影响。结果表明:试件均表现为弯曲延性破坏,受压钢筋的屈曲延缓,混凝土未发生明显剥落,柱整体性较好;随着试件的轴压比增大,其承载力明显提高,延性与耗能能力降低;减小箍筋间距,试件刚度退化减缓,延性与耗能能力显著提升;纵筋配筋率的增大,使得试件承载力与耗能能力显著提高,变形能力增强;高强钢筋与超高性能混凝土两者能够有效地协同工作,配置630MPa高强钢筋超高性能混凝土柱滞回曲线饱满,具有较高的承载力、延性及耗能能力,表现出较好的抗震性能。

To investigate the seismic behavior of ultra⁃high⁃performance concrete(UHPC)columns with 630MPa high strength reinforcing bars,four UHPC columns with 630MPa high strength steel bars are tested under the cyclic loading.The influence of axial compression ratio,stirrup spacing and longitudinal reinforcement ratio on the failure modes,mechanical performance,hysteretic curves and energy dissipation of the specimens are studied.The test results demonstrate that all the specimens presented flexural failure,concrete cover did not spall,the buckling of the compressive reinforcement is delayed,and the integrity of columns is excellent.The specimens with higher axial compression exhibit better bearing capacity,whereas the ductility and energy dissipation capacity adversely decrease.As the reduction of stirrup spacing,the stiffness degradation of the specimens is slowed down,and the ductility and energy dissipation of the specimens are significantly improved.Enhanced longitudinal reinforcement ratio,the bearing capacity,deformation capacity as well as the ductility of the specimens are also improved.The high⁃strength steel bar and ultra⁃high performance concrete can work together effectively,and the hysteretic curves of UHPC columns with 630MPa high strength steel bars are full,the ultimate load,ductility and energy dissipation capacity are high,which exhibit excellent seismic performance.