【作者】 沈凡；

【导师】 丁庆军；

【作者基本信息】 武汉理工大学 ， 材料学， 2012， 博士

【摘要】 钢箱梁具有自重轻、跨越能力大、架设方便等优点是我国桥梁建设,特别是大跨径桥梁建设的主要结构形式。然而,普通沥青基材料存在高温稳定性不良、与钢板粘结性差等问题,易产生推移、拥包等病害。因此,钢箱梁桥面铺装层材料一直是研究的热点和难点。针对钢箱梁桥面铺装材料需要具有良好的柔韧性、高温稳定性及与钢板粘结强度的要求,本文开发出一种水泥-乳化沥青-水性环氧树脂(cement-asphalt-epoxy, CAE)复合胶结钢箱梁桥面铺装材料,围绕材料的组成、结构、性能展开研究,取得了如下成果：本文提出了水泥-乳化沥青-水性环氧树脂复合胶结钢箱梁桥面铺装层材料的设计原理：在固化剂分子中引入醚基、羟基,与环氧树脂混合搅拌乳化成水性环氧树脂。水泥颗粒既吸附乳化沥青形成结构沥青,又与水性环氧树脂发生化学键合,被沥青与环氧树脂包裹,起连接介质作用,调控水泥、乳化沥青、水性环氧树脂的种类、颗粒尺寸及掺配比例,使之硬化后形成以水泥为连接介质的沥青与环氧树脂互穿网络结构。该结构以沥青为连续相,使材料具良好的柔韧性,可与钢板协调变形；环氧树脂为改性相,形成网络穿插于沥青中,提高了材料的高温稳定性和与钢板的粘结强度；水泥作为连接介质提高了材料的匀质性及水稳定性能,克服了环氧树脂(极性)与沥青(非极性)相容性差而分层离析的问题,并能够常温下拌合、浇注施工,改善了环氧沥青需要高温拌合碾压施工,固化速度快,施工可操作时间短的问题。分析研究了水泥的矿物组成、细度、种类,乳化沥青、水性环氧树脂的电荷类型、颗粒尺寸以及水泥、乳化沥青、水性环氧树脂三者间的掺配比例等因素,对CAE胶浆匀质性、水稳定性能、固结时间、回弹模量、与钢板的粘结强度、高低温性能的影响规律,确定了原材料的选配原则,提出了CAE胶浆及混凝土的设计与制备方法。运用XRD、IR、SEM、EDXA、水化热分析等测试手段,系统研究了CAE胶浆硬化机理及界面特性。CAE胶浆硬化过程主要包括沥青胶结、环氧树脂交联固化和水泥水化三个部分,在该体系中水泥水化速率水化放热量以及水化程度受沥青和环氧树脂的影响均较低。CAE胶浆硬化后形成了水泥-沥青、水泥-环氧树脂、沥青-环氧树脂三个界面。水泥-沥青、沥青-环氧树脂界面间主要靠物理吸附和机械啮合作用；水泥-环氧树脂界面间粘结主要依靠化学键合和环氧树脂极性基团的强吸附作用。水泥颗粒被环氧树脂和沥青包裹,与集料相隔离,CAE胶浆与集料界面组成主要为沥青和环氧树脂。CAE混凝土属于粘弹性材料,其静态模量与SMA沥青混凝土接近,抗剪强度、拉伸强度优于SMA沥青混凝土,与钢板的粘结性能、抗疲劳性能达到了环氧沥青混凝土的水平。采用蠕变试验,解析出CAE混凝土伯格斯方程中各力学参数,并根据参数的变化规律,探讨了水泥和水性环氧树脂对于CAE混凝土粘弹性力学的影响规律：水泥和环氧树脂均有利于降低材料的流动变形、延迟变形及提高温度稳定性,且水泥较环氧树脂作用更为明显。研究了不同温度、频率、材料组成对CAE混凝土的动态模量的影响规律,建立了CAE混凝土动态模量预测模型；基于现象力学法,建立了CAE混凝土弯曲疲劳方程,探讨了材料组成变化对弯曲疲劳寿命的影响规律；通过热氧老化和光氧老化试验,分析了材料组成与老化性能之间的关系；研究成果为新型钢箱梁桥面铺装材料的设计与制备提供了参考依据。系统研究了CAE混凝土的使用性能,在A/C=2、A/E=5/3时,80℃动稳定度达到22600次/mm-10℃低温弯曲应变达到2873με,浸水残留稳定度、冻融劈裂强度比大于90%,与钢板界面抗剪强度可以达到1.1MPa,具有优异的路面使用性能。根据线弹性理论和层状体系理论,采用ANSYS有限元分析了钢箱梁桥面铺装层弹性模量及厚度的变化对其受力特性的影响规律：随着CAE混凝土铺装厚度的增加,.横向最大拉应力、横向最大拉应变、竖向最大位移显著下降,纵向最大拉应力、纵向最大拉应变变化不明显；铺装层材料与钢板顶面之间的剪应力先增大后减小。满足铺装层结构受力要求,且有较高安全系数的CAE混凝土合适铺装厚度为60mm。综合考虑铺装层的经济性、抗滑特性及抗疲劳性能,针对依托工程,提出了水性环氧树脂粘结层+40mmCAE混凝土+高粘沥青防水粘结应力吸收层+40mm高粘SMA钢箱梁桥面铺装层的结构优化设计方案,并制定了其施工工艺。更多还原

【Abstract】 Steel box girder has become the main form of the long-span bridge construction in our country which has the advantages of light-weight, great ability of span, convenient erection etc. However, general asphalt-based materials has poor stability in the high temperature, poor adhesion of the steel plate, and extremely easy to produce the transposition and upheaval problem. Therefore, the research of steel bridge deck pavement materials has become one of the most focuses in the world. In this paper, for the requirement of flexibility, high temperature stability and cohesiveness to steel plate on Steel bridge deck pavement materials, Cement-Emulsified asphalt-Waterborne epoxy (CAE)composite cemented materials has been developed, and the composition, structure, properties of the materials has also been studied. The following results are achieved:This paper puts forward a suggestion of CAE composite binding steel bridge deck pavement materials. Introduce the hydroxyl, ether groups to curing agent molecules, mixing and stirring with epoxy resin to emulsify the waterborne epoxy resin. The cement particles adsorbed emulsified asphalt to form the structure asphalt and chemical bonding with the water-based epoxy resin, play a connecting role of media which wrapped in asphalt and epoxy resin. Control the type, particle size and blending proportion of cement, emulsified asphalt and water-based epoxy resin, to form the asphalt and epoxy interpenetrating network structure which connect with cement when the paste harden. The asphalt is the continuous phase of the structure, make the material with good flexibility, and consistent deformation ability with the steel plate; epoxy resin is the modify phase and forming network structure insert with asphalt; cement as the connection medium improve the material Homogeneity and water stability, overcome the epoxy resin (polar) and asphalt (nonpolar) compatibility sent to the problem of layered segregation, and could mix and pouring construction under normal temperature. Improve the problem of rapid curing speed and short time of operation in epoxy asphalt high temperature construction.The principle of Raw material selection, the design and preparation method of CAE was presented, based on researching the rules of the minerals, the fineness and the kinds of cement, the charge and the size of Emulsified Asphalt and Waterborne Epoxy Resin, and the ratio among cement, Emulsified Asphalt and Waterborne Epoxy Resin on the homogeneity, the water stability, the consolidation time, modulus of resilience and the cohesive strength with steel plate of CAE. CAE mortar hardening mechanism and interface characteristics was systematically researched, by using XRD, IR, SEM, EDXA and hydration heat analysis. CAE mortar hardening process mainly includes cementation of asphalt, solidification of epoxy and hydration of cement. The rate of cement hydration, heat release and the degree of hydration is low for the influencing of asphalt and epoxy. Interface of cement-asphalt, cement-epoxy, and asphalt-epoxy is forming after hardening of CAE mortar. Cement-asphalt, asphalt-epoxy interface depend mainly on the physical adsorption and mechanical engagement effect; the bond between the cement-epoxy interface mainly relay on the strong adsorption of the chemical bonding and epoxy polar groups. Cement particles are isolated from aggregate and packed with epoxy and asphalt, the interface of CAE mortar and aggregate is mainly composed of asphalt and epoxy.CAE concrete belong to the viscoelastic material, which static modulus is approached to SMA asphalt concrete. The shear strength, tensile strength is better than SMA asphalt concrete. The anti-fatigue performance and adhesive property with steel plate are equal to the epoxy asphalt concrete level. According to the results of creep test, the Burgers parameters were calculated. Through analyzing the law of the Burgers parameters, the influencing rule of waterborne epoxy resin and cement on sticky elastic mechanics of CAE was researched. Waterborne epoxy resin and cement are good for reducing the flow deformation, delay deformation and increasing temperature stability, and the role of the cement is more marked. Through researching the influencing rule of different temperature, frequency and material composition on the dynamic modulus of CAE, the prediction model of CAE concrete dynamic modulus was established. Based on the phenomenon mechanics method, the CAE concrete bending fatigue equation was established, and the influencing rule of the materials composition on bending fatigue life was analyzing. Through the hot oxygen aging and light oxygen aging test, the relationship between the material composition and the aging performance was analyzed. Research achievements provide a reference for the design and preparation of the new steel box girder bridge deck pavement materials.CAE concrete usability performances were researched. When A/C=2, A/E=5/3,80℃, the CAE, dynamic stability reaches22600times/mm,-10℃low-temperature bending strain reaches2873με, soaking remnants stability and the ratio of freeze-thaw split intensity ratio are greater than90%, shear strength of steel interface reaches1.1MPa, provided with excellent pavement performance.According to the linear-elastic theory and elastic multilayer theory (Muti-layer elastic system), the influencing law of mechanical characteristic were analyzed by ANSYS finite element, which include elastic modulus and thickness changes of steel box girder bridge deck pavement:Along with the increase of in laying thickness of CAE concrete, the maximum transverse tensile stress, maximum transverse tensile strain, vertical maximum displacement are decreased, but the maximum longitudinal tensile stress and maximum longitudinal strain do not changed significantly; The shear stress between paving materials and steel deck surfacing are increasing firstly and then decreasing. For the higher safety, the fit laying thickness of CAE is60mm. On this basis, considering the economic, skid resistance and anti-fatigue performance of the pavement, steel box girder bridge deck pavement structural optimization design program has proposed:Water-based epoxy resin adhesive layer+40cm CAE concrete layer+High viscosity bitumen waterproofing bond stress absorbing layer+40cm high viscosity SMA layer. And the process of CAE construction is drawing up.更多还原