环氧涂层钢筋海水珊瑚混凝土柱抗震性能与损伤评价

为了研究海水珊瑚混凝土柱的抗震性能，以混凝土类型、纵筋配筋率、配箍率和轴压比为主要参数，开展了6个环氧涂层钢筋混凝土柱低周反复荷载试验，分析了柱的破坏形态、承载力、延性和滞回耗能等变化。研究结果表明：环氧涂层钢筋海水珊瑚混凝土具有良好的抗震性能，海水珊瑚混凝土对柱延性、刚度退化有明显影响，而对承载力与耗能能力影响较小；海水珊瑚混凝土柱位移延性系数和承载力较普通混凝土柱降低19.25%与6.67%，而屈服荷载和峰值位移分别提高5.94%、25.90%；环氧涂层钢筋海水珊瑚混凝土柱耗能能力和滞回特性随纵筋配筋率和轴压比的变化而显著改变；增大配箍率可提高其延性。针对环氧涂层钢筋海水珊瑚混凝土柱提出了骨架曲线模型与抗震损伤评估模型。分析表明，侧移达到弹塑性层间位移角限值时，海水珊瑚混凝土柱纵筋配筋率或配箍率宜分别提高10%、16%，可以使其震损水平与普通混凝土柱相近。

Seismic performance and damage assessment of epoxy-coated steel bar-reinforced seawater coral concrete columns

A total of six columns were fabricated and tested under low-cycle reversed loading to study the seismic performance of seawater coral concrete (SCC) columns, covering four different parameters, namely, the type of concrete, longitudinal reinforcement ratio, stirrup ratio, and axial load ratio. The failure pattern, bearing capacity, ductility and hysteretic energy of SSC columns reinforced with epoxy-coated bars (ECBs) were analysed. The test results indicate that the seismic performance of ECB-reinforced SCC columns (ECB-SCCC) is favorable. The use of SCC leads to significant changes in the ductility and stiffness degradation of the columns. However, its effects on the bearing capacity and hysteretic behavior are negligible. Compared to ordinary concrete columns, the displacement ductility coefficient and bearing capacity of SCC columns are reduced by 19.25% and 6.67%, respectively, while the yield load and peak displacement are increased by 5.94% and 25.90%, respectively. It is found that the hysteretic characteristics of ECB-SCCC change significantly with the variations of longitudinal reinforcement ratio and axial load ratio. Increasing the stirrup ratio could enhance the ductility of specimens. Finally, the skeleton curve model of ECB-SCCC was derived, and the seismic damage assessment method was proposed. When the lateral displacement reaches the ultimate elasto-plastic inter-layer displacement angle, the longitudinal reinforcement ratio and the stirrup ratio are suggested to increase by 10% and 16%, respectively, so that the damage degree of the SCC column is similar to that of the ordinary concrete column.