装配式ECC/RC柱抗震性能试验研究

Experimental study on seismic performance of precast ECC/RC columns

为改善装配式混凝土柱的抗震性能,提出在RC柱潜在塑性铰区采用ECC替代普通混凝土的装配式ECC/RC柱。为研究装配式ECC/RC柱的抗震性能,设计并制作了1根现浇RC柱和4根装配式ECC/RC柱,通过拟静力试验,研究ECC高度和配箍率对柱破坏形态、滞回特性、耗能能力以及刚度退化等的影响。结果表明:与现浇RC柱相比,装配式ECC/RC柱承载能力以及耗能能力得到提升,同时柱损伤程度得到明显改善,震后可恢复性大幅度提升;对于装配式ECC/RC柱,在其他条件相同情况下,增加ECC高度提高了柱承载能力、耗能能力和变形能力,避免塑性铰区上移,但对柱的刚度退化影响不大;而提高配箍率降低了柱的变形能力,导致塑性铰区上移,但对柱的刚度退化和耗能能力影响较小。

To improve the seismic performance of precast concrete columns,an assembled ECC/RC column using ECC instead of standard concrete in the potential plastic hinge zone of RC columns was proposed.To investigate the seismic performance of precast ECC/RC columns,one cast-in-place RC column and four assembled ECC/RC columns were designed and fabricated.The effects of ECC height and stirrup ratio on the damage pattern,hysteresis characteristics,energy dissipation capacity,and stiffness degradation of the specimens were investigated through quasi-static tests.The results show that,compared to cast-in-place RC columns,the load-carrying capacity and energy dissipation capacity of precast ECC/RC columns are improved.Additionally,the damage degree of the specimens is significantly reduced,and the postseismic recoverability is greatly enhanced.Keeping other factors constant,for the precast ECC/RC columns,increasing ECC height increases the structural load-bearing capacity,energy dissipation capacity,and deformation capacity,and avoids the upward shift of the plastic hinge zone,but the stiffness degradation of columns is not much affected.Conversely,increasing the stirrup ratio reduces the deformation capacity of the structure,resulting in an upward shift of the plastic hinge zone,but has less effect on the stiffness degradation of the columns and the energy dissipation capacity.