改性沥青混合料界面力学特性试验研究

发布时间：2019-04-01 16:17

【摘要】：随着公共基础设施的不断完善,我国的道路建设事业也取得了长足的发展。沥青路面因其良好的路用性能已成为国内外公路及市政道路建设最重要的路面类型。同时,国内外相关学者纷纷致力于对沥青、沥青混合料、沥青路面病害等课题的研究,研究成果层出不穷。沥青路面的开裂本质即沥青混合料中粗骨料与胶结料的粘结失效,为了更细致地讨论混合料开裂过程中的界面区域的力学特性变化,本文基于数字图像相关技术的理论,利用半圆弯曲试验,从细观尺度讨论了两种常用沥青路面面层材料SBS改性沥青混合料与胶粉改性沥青混合料在裂纹的起裂与发展过程中变形场的变化特征和力学性能,并分析了温度老化、紫外线光照老化、水冻融循环、盐溶液冻融循环对两种材料在破坏过程中变形场及力学性能的影响。通过对VIC-3D数据及电镜扫描图像的分析得出,沥青混合料试件可分为沥青砂浆、界面区、粗集料三部分研究,其中界面区属于试件的最薄弱部分,裂纹的起裂与宏观裂纹的发展均沿界面区进行;宏观裂纹的发展包括微裂纹的起裂与发展贯通至宏观裂纹两个过程,老化主要影响了改性沥青的性质,冻融循环主要影响界面区的性质,两者均使微裂纹发展为宏观裂纹的时间缩短、宏观裂纹的形成提前。利用断裂能密度FE和断裂韧性Jc作为参数来评价SBS改性沥青混合料和胶粉改性沥青混合料的断裂性能,所得结果趋势相同,证明了这两个参数的可行性;胶粉改性沥青混合料试件及在紫外线老化、温度老化、水冻融循环、盐溶液冻融循环四种环境下试件的FE及Jc均大于对应的SBS改性沥青混合料试件,且经四种环境作用后的变化程度小于SBS沥青混合料试件,证明胶粉改性沥青混合料力学性能受环境影响程度较小,且具有更好的低温抗裂性能;紫外线老化对沥青混合料试件力学性能的影响最大,其余依次为温度老化,盐溶液冻融循环,水冻融循环。此外,基于内聚力模型的原理对室内试验的试件进行建模,并利用经验公式推导出相应的粘弹性参数,用ABAQUS有限元软件对沥青混合料试件的破坏过程进行模拟。结果表明,数值模拟结果与试验结果相近,利用有限元的模拟可以对试验结果进行验证及预测。
[Abstract]:With the improvement of public infrastructure, our country's road construction has made great progress. The asphalt pavement has become the most important pavement type for highway and municipal road construction at home and abroad because of its good road performance. At the same time, domestic and foreign scholars have been working on the research of asphalt, asphalt mixture and asphalt pavement disease. The cracking nature of the asphalt pavement is the bond failure of the coarse aggregate and the cementing material in the asphalt mixture, and in order to discuss the mechanical property change of the interface region in the cracking process of the mixed material in more detail, the semi-circular bending test is used in the paper based on the theory of the related technology of the digital image. The change characteristics and mechanical properties of two kinds of asphalt mixture and rubber powder modified asphalt mixture in the process of crack initiation and development were discussed from the micro-scale, and the temperature aging, ultraviolet light aging and water freeze-thaw cycle were also analyzed. The effect of salt solution freeze-thaw cycle on the deformation and mechanical properties of two materials in the process of destruction. Through the analysis of the VIC-3D data and the scanning image of the electron microscope, the asphalt mixture test piece can be divided into three parts: the asphalt mortar, the interface area and the coarse aggregate, where the interface area belongs to the weakest part of the test piece, and the crack initiation and the development of the macro crack are all along the interface area; The development of macrocracks includes the initiation and development of micro-cracks, which mainly affect the properties of the modified asphalt, and the freeze-thaw cycle mainly affects the properties of the interface area, both of which have the micro-crack development as the macro-crack time and the formation advance of the macro-crack. By using the fracture energy density FE and the fracture toughness Jc as parameters, the fracture property of the SBS modified asphalt mixture and the rubber powder modified asphalt mixture is evaluated, the result trend is the same, the feasibility of the two parameters is proved, the rubber powder modified asphalt mixture test piece and the rubber powder modified asphalt mixture test piece and the rubber powder modified asphalt mixture test piece are aged, the FE and the Jc of the test pieces are larger than the corresponding SBS modified asphalt mixture test pieces under the four conditions of temperature aging, water freezing and thawing, the salt solution freezing and thawing cycle, and the change degree after the four environmental effects is less than that of the SBS asphalt mixture test piece, It is proved that the mechanical property of the rubber powder modified asphalt mixture is less affected by the environment, and has better low-temperature anti-cracking performance; the effect of the ultraviolet aging on the mechanical properties of the asphalt mixture test piece is the largest, and the rest are temperature aging, salt solution freezing and thawing, and water freeze-thaw cycle. In addition, based on the principle of the cohesive force model, the test piece of the indoor test is modeled, and the corresponding viscoelastic parameters are derived by using the empirical formula, and the destruction process of the asphalt mixture test piece is simulated by using the ABAQUS finite element software. The results show that the numerical simulation results are close to the test results, and the simulation of the finite element can be used to validate and predict the test results.
【学位授予单位】：内蒙古工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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