钢-高强再生混凝土组合柱抗震性能及破坏机理

The efficient utilization of waste concrete is an urgent subject in the research and industry field. Based on the previous studies on the preparation of high-strength recycled concrete and the technology of reinforced high strength recycled concrete structure, the steel reinforced high strength recycled concrete structure will be further researched and developed. In this study, the seismic performance and failure mechanism of the column, which is usually considered as the most important member of the structure, will be studied. The study mainly focuses on: (1) The bond-slip behavior and failure mechanism between steel and high strength recycled concrete. Bond-slip push out full-scale test will be carried out, and the effect of the concrete strength, studs and stiffeners on bond behavior will be investigated. The constitutive relationship will be established, and the bond-slip failure mechanism between steel and high strength recycled concrete will be revealed. (2) The seismic performance and failure mechanism of steel reinforced high strength recycled concrete columns. Low cyclic loading test on high strength recycled concrete filled steel tube columns with different design parameters will be carried out. The bearing capacity, stiffness, ductility, hysteretic behavior and damage process will be studied. The load bearing capacity calculation model and restoring force model will be established. Also, numerical simulation will be carried out to reveal the seismic mechanism. (3) Based on the test and FEM numerical simulation, the calculation analysis on steel reinforced high strength recycled concrete composite columns and structures will be carried out and the seismic mechanism will be studied. The seismic design method and structural measures will be proposed, which is fundamental work for its further application in engineering practice.

废弃混凝土的高效利用是国内外学者和工程界十分关注和亟待解决的问题。在研发了高强再生混凝土制备及钢筋高强再生混凝土结构技术基础上，进一步研发钢-高强再生混凝土组合结构，涉及关键构件钢-高强再生混凝土组合柱的抗震性能及破坏机理。重点研究：（1）钢与高强再生混凝土黏结-滑移性能及破坏机理。进行钢与高强再生混凝土黏结-滑移性能包括足尺试件的推出试验，研究混凝土、栓钉、肋板、分腔等构造对黏结-滑移性能的影响，建立本构关系，揭示钢与高强再生混凝土黏结-滑移破坏机理。（2）钢-高强再生混凝土组合柱抗震性能及破坏机理。进行不同设计参数的钢管高强再生混凝土柱等足尺试件的低周反复荷载试验，研究承载力、刚度、延性、滞回特性及损伤演化过程，建立承载力模型和恢复力模型，进行数值模拟，揭示破坏机理。（3）基于本项目及课题组前期试验和理论研究，提出钢-高强再生混凝土组合柱性能化抗震设计控制参数及设计方法。

研究再生混凝土组合结构对推进建筑垃圾资源化，促进资源与环境保护，意义重大。本项目在课题组研发的高强再生混凝土制备及钢筋高强再生混凝土结构技术基础上，进一步研发了钢-高强再生混凝土组合结构的关键构件，即钢-高强再生混凝土组合柱的抗震性能及破坏机理。主要贡献：（1）进行了48个型钢再生混凝土模型黏结-滑移试件的推出试验及55个不同构造的圆钢管及方钢管与高强再生混凝土黏结-滑移性能足尺试件推出试验研究，分析了试件黏结-滑移曲线、极限荷载、型钢应变以及破坏形态；进行了不同设计参数的11个钢筋高强再生混凝土方柱和型钢再生混凝土方柱足尺试件的低周往复荷载试验、7个方钢管再生混凝土柱足尺试件低周往复荷载试验、12个足尺圆钢管普通混凝土柱试件的低周反复荷载试验，分析了各试件的承载力、刚度及退化过程、延性、滞回特性、抗震耗能性能、粘滞阻尼系数；获得了较系统的试验成果和丰富的试验数据。（2）基于试验研究，进行了理论分析和数值模拟，阐明了钢与再生混凝土界面粘结作用机制、界面黏结强度及设计参数对黏结强度的影响规律，提出了钢与再生混凝土黏结-滑移本构关系及界面黏结强度计算模型与计算计算方法；阐明钢-高强再生混凝土组合柱损伤演化过程，得到了不同设计参数对钢-高强再生混凝土组合柱抗震性能的影响规律，揭示了屈服机制和破坏机理，提出了高轴压比下考虑二阶效应的水平承载力计算方法，建立了考虑压、弯、剪相关性的钢-高强再生混凝土组合柱承载力计算模型及恢复力模型并给出了滞回规则。（3）提出钢-高强再生混凝土组合柱性能化抗震设计方法。研究表明：钢管内设置加劲肋或拉结筋可明显提高钢管与混凝土的界面黏结性能；与腔体无构造试件相比，内置环向肋和竖向肋的组合构造界面黏结强度提高了19.9倍；型钢再生混凝土柱与钢筋再生混凝土柱相比，抗震承载力提高了11%~22%；剪跨比与轴压比对试件水平承载力影响显著；钢-高强再生混凝土柱可用于工程抗震设计。