摘要
为了减少沥青混合料设计过程中的误差和工作量，提高沥青混合料设计的社会经济效益，提出基于离散单元法进行骨架密实型混合料级配可视化设计和评价的方法，并对理想骨架结构的细观力学指标进行了定量分析。结果表明：在应用离散元方法进行混合料级配设计过程中，不需测量集料毛体积密度和混合料体积指标等中间变量，操作方便、数据变异小，克服了传统试验误差较大和试验量大的不足，极大地提高了沥青混合料设计的效率和经济性；骨架密实型混合料内部平均接触力与最大接触力呈线性相关关系，平均接触力、最大接触力与混合料的空隙率并无明显的相关关系；由粒径大于2．36mm理想球形粗集料构成的主骨架结构，平均配位数一般在3．3～3．5之间，当细集料掺入时，混合料的平均配位数有所降低；随着次一档集料的掺入，混合料内部的应力发生重分布，应力逐渐向细集料转移。对骨架密实抗车辙型沥青混合料设计来说，较粗的级配应提高主骨架的嵌挤能力，而较细的级配重点在于改善沥青砂浆的抗变形能力。
To reduce errors and test quantities in design of asphalt mixture, improving the social and economic benefits of the asphalt mixture design, the skeleton dense mixture visualization gradation design and evaluation method is put forward based on Discrete Element Method, the microscopic evaluation indexes of ideal skeleton structure were also quantitative analyzed. The results indicate that during the process of mixture gradation design by Discrete Element Method, having the advantages of without measure the intermediate variables such as bulk density of aggregates and volume indexes of mixture, convenient operation and small discreteness of data, the design method overcomes the traditional test shortcomings of large errors and test quantities, and greatly improves the efficiency and economy of mixture design. There is a linear correlation between the average contact force and maximum contact force in skeleton dense mixture, but the average contact force, as well as maximum contact force has no obvious correlation with air void. The main skeleton structure constituted by ideal spherical shape of coarse aggregates whose particle size greater than 2.36ram, the mean coordination number is generally between 3.3 ~ 3.5, when the fine aggregate incorporation, the mean coordination number of the mixture decreased. The stress is redistributed in mixture characterized by stress transfer to the fine aggregate with the incorporation of finer particle size aggregate. For designing skeleton dense structure rut resistance asphalt mixture, coarse grade should improve the interlocking abilities of main skeleton, and finer gradation should focus on improving the resistance to deformation of asphalt mortar.
出处
《公路》
北大核心
2015年第9期200-206,共7页
Highway
基金
国家自然科学基金资助项目
项目编号51278203
交通运输部应用基础研究项目
项目编号2013319223020
关键词
道路工程
骨架密实型混合料
离散单元法
分级掺配法
可视化设计
road engineering
skeleton dense structure asphalt mixture
Discrete Element Method
Multilevel Mixing Method
visualization design
