高强钢筋增强UHPC-NC组合柱抗震性能研究

Seismic behavior of UHPC-NC composite columns reinforced by high-strength steel bars

摘要:

为探讨高强钢筋增强UHPC-NC组合柱抗震性能,基于大型有限元程序ABAQUS,结合UHPC、NC和高强钢筋材料本构关系,校准损伤塑性模型中相关参数,建立高强钢筋增强UHPC-NC组合柱抗震有限元模型。通过与3个NC柱和3个UHPC柱拟静力试验结果对比,验证分析模型的有效性。在此基础上,进一步探讨轴压比、纵筋直径、纵筋强度、箍筋间距和UHPC高度等敏感参数对高强钢筋增强UHPC-NC组合柱抗震性能的影响。结果表明,高强钢筋增强UHPC-NC组合柱位移延性系数随轴压比、纵筋直径和箍筋间距的增大而降低,随纵筋强度和UHPC高度的增加表现出先增大后逐渐平缓的趋势,合适的UHPC替换高度能充分发挥高强钢筋和UHPC材料特性并取得良好的经济性。

Abstract:

To study the seismic behavior of ultra-high performance concrete (UHPC)-normal concrete (NC) composite columns reinforced by high-strength steel bars, based on the finite element program ABAQUS, the relevant parameters of the damage plastic model were calibrated and a seismic finite element model of UHPC-NC composite columns reinforced by high-strength steel bars was established. The validity of the proposed model was verified by comparing with the pseudo static test results of three NC columns and three UHPC columns. On this basis, the parameters affecting the seismic behavior of UHPC-NC composite columns reinforced by high-strength steel bars were analyzed, i.e., the axial compression ratio, the diameter and strength of longitudinal bar, the stirrup spacing, and the UHPC height. The results showed that, the displacement ductility coefficient of the composite column decreases with the increase of axial compression ratio, longitudinal bar diameter, and stirrup spacing; while it first increases and then gradually keep flat with the increase of longitudinal bar strength and UHPC height. The appropriate replacement height of UHPC can give full play to the material characteristics of high-strength reinforcement and UHPC, thus achieving good economy.