钢桥面环氧沥青铺装粘结层性能与结构力学分析

发布时间：2019-01-02 14:23

【摘要】：随着经济持续快速发展,大跨径公路钢桥在我国交通领域也越来越被广泛应用。钢桥面铺装对保证良好的行车环境起到重要作用,目前钢桥面铺装是大跨径公路钢桥研究的重点和难点之一。正交异性钢桥面由于本身结构特征,受力变形复杂,一般沥青混凝土铺装较难达到铺装性能要求,环氧沥青混凝土具有高强度、抗疲劳、耐高温等优点,现已逐步运用到我国的钢桥面铺装上,部分环氧沥青混凝土铺装仍然有开裂、脱层、鼓包等病害问题。钢桥面铺装粘结层是铺装结构体系的关键环节,但目前缺乏明确统一的环氧沥青铺装粘结层检测试验评价方法,对于环氧沥青铺装粘结界面微观结构也缺少深入研究。关于钢桥面环氧沥青铺装结构分析已有大量研究工作,但对有限元中单元尺寸、荷载加载方式、横坡影响等问题尚缺乏研究。本文针对铺装结构力学计算和粘结层问题开展以下研究工作。(1)针对环氧树脂粘结层的力学性能进行正交试验设计,通过拉剪和拉拔试验评价粘结层粘结性能对三个因素(粘结层厚度、加载速率、温度)敏感性,并通过相关性分析,建立粘结层剪切与拉拔强度的关系,评价粘结层性能检测试验影响因素。(2)进行粗、细级配铺装层与钢板粘结性能试验,确定级配对粘结层粘结能力的影响,通过数字图像处理量化不同级配与钢板接触状态,建立粗集料在界面附近区域比例与界面粘结强度关系。通过微观图像观测,对比分析界面接触区域与混合料内部环氧树脂微观分布情况。(3)结合虎门大桥铺装工程建立有限元数值模型,比较单元网格划分尺寸对计算结果影响,确定模型单元合理网格尺寸,同时计算分析铺装层模量、超载率、单双轮加载方式、铺装层开裂对铺装层力学响应影响。(4)在数值模型中计算分析横坡对铺装层两侧轮迹带上力学响应差异的影响,基于虎门大桥铺装层两侧轮迹带病害差异现象,分析了横坡对钢桥面铺装力学响应影响。粘结层检测评价试验中表明粘结层力学性能对温度因素最敏感,粘结层剪切与拉伸强度呈二次曲线关系。粗、细级配铺装层与钢板接触状态中,粗级配中较多粗集料直接与钢板接触,试验结果表明粗级配界面粘结强度比细级配的低。通过有限元数值模拟计算不同参数下虎门大桥铺装层受力情况,结果说明虎门大桥横坡对铺装层力学响应存在显著影响。
[Abstract]:With the sustained and rapid development of economy, long-span highway steel bridges are more and more widely used in the field of transportation in China. Steel deck pavement plays an important role in ensuring good driving environment. At present, steel deck pavement is one of the key and difficult points in the research of long span highway steel bridge. The orthotropic steel deck has the advantages of high strength, fatigue resistance and high temperature resistance due to its structural characteristics and complex deformation, so it is difficult for asphalt concrete pavement to meet the requirements of pavement performance. It has been gradually applied to steel bridge deck pavement in China, and some of the epoxy asphalt concrete pavement still have problems such as cracking, delamination, bulging and so on. The bond layer of steel bridge deck pavement is the key link of pavement structure system, but there is no clear and unified testing and evaluation method of epoxy asphalt pavement bond layer at present, and the microstructure of bond interface of epoxy asphalt pavement is also lack of in-depth study. A lot of research work has been done on the analysis of steel bridge deck epoxy asphalt pavement structure, but there is still no research on the element size, load loading mode and the influence of transverse slope in finite element method. In this paper, the following research work is carried out on mechanical calculation and bonding layer of pavement structure. (1) orthogonal experimental design for mechanical properties of epoxy resin adhesive layer is carried out. The sensitivity of bond properties to three factors (bond thickness, loading rate, temperature) was evaluated by tensile shear and drawing tests. The relationship between bond shear and drawing strength was established by correlation analysis. To evaluate the influencing factors of bond layer performance test. (2) to determine the influence of gradation on bond ability between coarse and fine grade paving layer and steel plate, and to quantify the contact state between different grade and steel plate by digital image processing. The relationship between the ratio of coarse aggregate near the interface and the bond strength of interface is established. Through microscopic image observation, the microcosmic distribution of epoxy resin in interface contact area and mixture is compared and analyzed. (3) the finite element numerical model is established in combination with Humen Bridge pavement project, and the effect of mesh size on the calculation results is compared. The reasonable mesh size of the model element is determined, and the modulus of the pavement layer, the overload rate and the loading mode of the single and double wheels are calculated and analyzed at the same time. The influence of pavement cracking on the mechanical response of pavement is analyzed. (4) the influence of lateral slope on the mechanical response difference of wheel track on both sides of pavement is calculated and analyzed in the numerical model, based on the phenomenon of disease difference of wheel track on both sides of pavement of Humen Bridge. The influence of transverse slope on the mechanical response of steel deck pavement is analyzed. The mechanical properties of the bond layer are most sensitive to the temperature factor in the test and evaluation of the bond layer. The shear and tensile strength of the bond layer show a quadratic curve relationship. In the contact state between coarse and fine grade pavement and steel plate, more coarse aggregates are directly in contact with steel plate in coarse gradation. The experimental results show that the bond strength of coarse gradation interface is lower than that of fine grade. The stress on the pavement of Humen Bridge under different parameters is calculated by finite element numerical simulation. The results show that the transverse slope of Humen Bridge has a significant effect on the mechanical response of the pavement.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U443.33

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