【作者】 迟耀辉；

【导师】 王立久；

【作者基本信息】 大连理工大学 ， 材料学， 2006， 博士

【摘要】 钢管混凝土结构将钢和混凝土的优点有机结合，由于具有良好的强度和延性、抗震性能良好、施工快速等优点，因而在桥梁、高层建筑得以广泛应用。 但是钢管混凝土结构存在着以下缺点：在钢管混凝土施工过程中，存在大量的能源、资源浪费和环境污染现象；需要额外防火、防锈，维护费用高；钢管混凝土结构节点连接不便：由于脱粘，使钢管对混凝土的紧箍作用不能够充分发挥。 因而，钢管混凝土结构有赖进一步完善和发展。 本文旨在利用材料过程工程学原理，解决上述问题。通过对钢管混凝土结构施工过程及其诸要素的优化组合，改变施工过程的资源流、能源流，提高钢管混凝土的工作性能，满足节省资源、能源、保护环境和符合可持续发展战略要求。 通过将电渗技术引入到混凝土施工过程，成功解决了混凝土大水灰比施工、小水灰比固化的矛盾；由于不添加任何化学外加剂，因而解决了由化学外加剂引起的浪费能源、资源、污染环境的问题。通过大量添加工业废弃物粉煤灰，实现了资源的再利用。 本文实验分析了水化时间、电流强度、水灰比、粉煤灰掺量等因素对电渗滤水的影响，推导了电渗滤水量与滤水时间的关系公式，给出了可用于实际工程的电渗滤水混凝土配合比设计方法。实验表明电渗技术可以显著提高滤水混凝土的滤水速度，明显提高混凝土的强度，并有很好的经济性。 本文实验研究了一种新型的钢管混凝土组合结构—模网钢管混凝土结构。模网钢管混凝土将模网混凝土和钢管混凝土的优势有机结合起来，又具有二者不具备的独特优点。本文对模网钢管混凝土组合柱在轴心压力作用下的力学性能进行了研究分析。实验证明模网钢管混凝土组合结构具有卓越的工作性能、良好的强度和变形能力。 由于模网的约束作用，模网钢管混凝土组合柱不出现一般钢管混凝土组合柱过早出现保护层混凝土大面积剥落、脱离、崩溃导致承载力急剧下降的现象。组合柱达到极限承载力后，由于保护层混凝土退出工作后核心钢管混凝土承担了大部分的轴向压力，组合柱整体承载力下降平缓，表现出良好的延性。 普通混凝土在硬化过程中产生收缩，造成钢管和核心混凝土脱粘，使钢管的约束作用降低。本文通过大剂量添加MgO膨胀剂，利用MgO膨胀产生的自应力成功解决了钢管混凝土结构普遍存在的脱粘问题，并能充分发挥钢管对混凝土的紧箍作用，提高钢管混凝土的强度。由于MgO具有延迟膨胀的特性，因而能够保证膨胀变形以及自应力长期保持稳定，确保自应力钢管混凝土承载力长期稳定。更多还原

【Abstract】 Concrete-filled steel tube combines the beneficial qualities of both steel and concrete, namely, high strength, excellent ductility, large energy absorption capacity and convenience of construction. Therefore the use of concrete-filled steel tube has become widespread.But there are still some defects in concrete-filled steel tube, such as waste of resource and energy, environment pollution, needs for extra fireproofing and rust prevention, high maintenance expense, inconvenience of beam-column connections, insufficiency of confinement effect owing to the interface disengaging. Thus a further progress of concrete-filled steel tube is needed.The purpose of this paper is to solve above problems by using the principle of process engineering of materials. By using the principle of process engineering to optimize the factors of concrete and change the resource and energy flow of construction to enhance the performance of workability of concrete-filled steel tube and to meet the requirement of saving the resource and energy, protecting the environment and to conform the stratagem of the sustainable development. High water cement ratio during construction and low water cement ratio during solidification are realized by using electroosmosis technology in the process of concrete construction; the problems such as pollution, poor volume stability and higher cost causing by admixture were resolved; realized the reuse of resource by added large amount of fly ash.Main influencing factors of electroosmosis such as hydration time, current intensity, water cement ratio and quantity of fly ash are analyzed. Relationship between filtering capacity and time is deduced. Design method for mix proportions, which can be used in real engineering, is proposed. The experimental results indicate that electroosmosis technology can further the filtering velocity markedly, increase the compressive strength of concrete significantly and has fine economical efficiency.A new type of composite construction—concrete-filled steel tube with formwork composite construction is studied. Concrete-filled steel tube with formwork composite construction combines the beneficial qualities of both steel and concrete and has unique advantage. Mechanical properties of composite columns subjected to axial compressive loading are investigated.The experimental results indicate that the composite construction has excellent work performance, high strength and good deformation capacity. Owing to the confinement of formwork, the composite columns differ from common concrete-filled steel tube columns which exterior concrete spalls off too early thus lead to the sudden decrease of bearing capacity. After the ultimate strength is reached, the composite columns show a ductile更多还原