【作者】 王勇威；

【导师】 蒲心诚； 杨长辉；

【作者基本信息】 重庆大学 ， 材料学， 2004， 博士

【摘要】 人类创造了一个又一个辉煌，但同时又为地球和人类本身留下了一个又一个的创伤或隐患。时至今日，人类面临人口剧增、土地面积剧减、资源和能源过度消耗、环境污染严重等几大难题，人类的生存受到严重的挑战。为了适应生存与发展，人类拨动了向高空发展、向沙漠和草原进军、向南北极地探索、向海洋扩张、向太空迈进的主旋律，于是，就有了“空中城市”、“海市蜃楼”、“海洋站”、“空中电梯”、“太空基地”等设想；也有了可持续发展策略和“绿色革命”口号。 人类要解决生存和发展难题，要满足城市化和基础设施建设需求，要实现自己的众多美妙设想，大力研究、开发和应用新型材料将是必然趋势，而首当其冲的将是新型结构材料的开发和应用。可以预见的是，未来的新型结构材料应是能满足超大高度或超大跨度要求的结构材料。基于此点，本文提出了千米承压材料的定义、性能要求和制备途径，并展望了此种新型结构材料的应用前景。在全面考察目前可供大量应用的结构材料以及展望了两大主流结构材料——钢材和混凝土的发展趋势后，作者认为钢管特超强混凝土是千米承压材料的有力候选者。文末，通过对超高强钢管特超强混凝土与5种型钢的计算承载力、名义强度、质量比强度、柱质量比较、柱经济成本的比较，提出了超高强钢管特超强混凝土是千米承压材料的最佳候选者的结论。 特超强混凝土拥有强度高、弹性模量大、耐久性优异等诸多优点，但是其脆性很大，普通的配筋方式已不适宜；采用钢管套箍的形式是目前最佳的选择。要使特超强混凝土真正能够满足工程要求，除此之外，尚需要解决其工作性能问题和收缩，特别是自收缩过大的问题，以及提供必要的基础力学性能指标。在解决了特超强混凝土自身的基本问题后，将其应用于钢管混凝土结构中，则必须掌握其制作技术，知晓其力学性态和本构关系，明了钢管和特超强混凝土的协同工作机理，由此，本文开展了如下研究工作： 1) 研制强度为100～160MPa的特超强／超高强混凝土，分析混凝土内部的微观结构； 2) 研究特超强／超高强混凝土的收缩(主要是自收缩)问题，探讨有效降低特超强／超高强混凝土收缩的途径； 3) 测试特超强／超高强混凝土的力学性能，包括抗压强度、劈拉强度、抗折强度、轴压强度、轴压应力-应变曲线，分析轴压应力-应变曲线特点，并对其本构关系进行构造、拟合； 4) 制作钢管特超强／超高强混凝土构件，测试构件的极限荷载、极限变形重庆大学博士学位论文 以及荷载一位移关系; 5)分析钢管特超强/超高强混凝土的荷载一位移曲线，建立其本构关系模 型，并探讨其协同工作机理。 通过对特超强混凝土和钢管特超强混凝土的试验研究和数值分析，本文取得了 以下研究结果: 1)采用背散射电子显微镜观察了特超强/超高强混凝土的微观形态，并根据物 质元素背散射电子图像的灰度规律，运用颜色分离和局部区域去斑等图像 处理技术，对特超强混凝土的亚微观组成进行了分析; 2)研究了42组抗压强度为50MPa~165MPa的混凝土的收缩(主要是自收缩)， 发现特超强混凝土的自收缩比较大，特别是3天前的自收缩很大。采用掺 减缩剂、惰性矿物掺合料、微孔掺合料和加强早期，特别是3天前的水养 护，较为完美地解决了特超强/超高强混凝土收缩过大的问题; 3)通过对特超强混凝土的早期小时抗压强度、劈拉强度和收缩的研究，提出 了超高强混凝土与特超强混凝土的收缩测量方法; 4)获得了立方体抗压强度为50MPa~165MPa范围内的高强、超高强、特超强 混凝土的各种强度性能、变形性能与抗压强度的关系式，以及各种强度等 级的超高强、特超强混凝土的系列力学性能指标; 5)提出了抗压强度为50MPa~165MPa范围内的混凝土的应力一应变本构关系， 只需要给出混凝土的立方体抗压强度，就可以确定轴心受压应力一应变关系; 6)通过对23组68根钢管特超强超高强混凝土短柱的研究，回归得出了极限 荷载、极限变形、低谷荷载、低谷变形的计算关系式，并介绍和分析了钢 管混凝土轴压试验结束后的外观形态、体积变形以及核心混凝土的破坏形 态; 7)采用数值分析方法，将钢管混凝土视为统一材料，提出了其荷载一变形本构 关系，通过上升段参数c和下降段参数b，只需要给出混凝土的抗压强度、 钢管外径和璧厚、钢材屈服强度，就可以确定所制得的钢管特超强/超高强 混凝土的荷载一位移曲线; 8)采用内力分析方法，首次研究了超高强钢管特超强混凝土的协同工作机理。 通过对钢管的纵向和环向应力以及混凝土纵向应力和径向紧箍力的发展的 研究，发现5135钢管特超强混凝土中，混凝土先于钢管破坏，但构件极限 荷载相应于钢管屈服时。关键词:钢管混凝土，超高强混凝土，自收缩，力学性能，本构关系，微观结构， 千米承压材料更多还原

【Abstract】 Human beings have gained one after another brilliant achievements, but at the same time they also bring the earth and themselves into one after another hidden troubles. Today, human beings face lots of unprecedented challenges, such as explosion of the population, acute reduction of the soil area, exhaustion of the resource and energy and serious pollution of the environment. For the living of human beings and the benefits of offspring, we should consider moving our feet to the sky, the desert, the grassland, the polar region and even the ocean and the outer space. So human beings begin to dream of constructing the Sky City, the Mirage, the Ocean Station, the Space Elevator, the Outer Space Bastion, and etc.To get out of the difficult dilemma of living and development, meet the needs of urbanization and infrastructure construction, and realize the dream of human beings , an irreversible trend is to develop, to research and to utilize new materials, first of which are structural materials.We can foresee that new structural materials should fulfill the requirements of ultra great height or ultra large span (even over 1000 meters). Based on this and the viewpoints of professor PU Xincheng, the author defines the Kilometer Compressive Material (KCM), gives the criterion of the properties and choosing requirements, brings forward the preparation method of the KCM, and prospects the future of this new structural material.After investigating the structural materials largely used hitherto and the development trend of two leading structural materials, namely, steel and concrete, the author drew the conclusion that the steel tubular confined super high strength concrete was one of the best candidates for KCM. In the last chapter of the thesis, through case compute, the author gained the calculated loading, the nominal strength, the strength to weight ratio, the weight of column, and the cost of super high strength steel confined super high strength concrete column. By comparing these properties with 5 types of shaped steel columns, the author concluded that the super high strength steel confined ultra high strength concrete was the best choice for KCM.Super high strength concrete (SHHC) has a lot of advantages over ordinary concrete, such as high strength and elastic modulus, and good durability. Howerver, its large fragility makes the ordinary bar arrangement unsuitable and utilization of steeltube confined concrete is the best replacement for this. Besides, to make the super high strength concrete completely meet the needs of constrution in situ, workability and shrinkage, expecially large autogenous shrinkage, should be solved and necessary basic mechanical properties should be provided as well. After settling problems of super high strengh concrete itself and applying it to the steel tube confined concrete structure, the preparing techniques, mechanical behavior, stress-strain response, and coordination between SHHC and steel tube should be known first. Therefore, five parts of work are included in the reasearch:1) Research and develop super high strength concrete with compressive strength about 100~160MPa, and analyze its microstructure.2) Study the shrinkage (especially autogenious shrinkage ) of SHHC, and probe into the efficient way of reducing it.3) Measure the mechanical properties of SHHC, including cubic compressive strength, splitting tensile strength, flexural strength, uniaxial compressive strength, uniaxial stress-strain response curve; analyze the characteristics of stress-strain response curve; and simulate and build the stress-strain response relationship.4) Prepare steel tube confined SHHC member, measure the limit load, ultimate deformation, and load-displacement relationship.5) Analyze the load-displacement relationship curve of steel tube confined SHHC, build stress-strain model, and discuss the coordinate work mechanism.After experiment work and numerical analyses, the writer achieved the results as follows:1) With backscattered scanning electron microscope (BSE), the author qualitativel更多还原