沥青混合料梯形梁动态模量试验研究

发布时间：2018-03-26 17:08

本文选题：沥青混合料　切入点：动态模量　出处：《长沙理工大学》2015年硕士论文

【摘要】：路面结构在服役过程中受到来自车辆、环境等各种因素的综合作用。无论是车辆荷载还是温度交替,都是一个不断变化的动态过程。沥青路面采用的沥青混合料是一种典型的粘弹性材料,力学性能对温度和频率的变化非常敏感,在动态荷载作用下和在静态荷载作用下所表现出的力学响应是十分不同的。目前,国际上普遍采用路面结构和路面材料的动态分析方法,动态模量作为重要的设计参数已经纳入到AASHTO-2002等设计方法中。因此,基于我国的现实情况,对沥青混合料的动态模量进行研究具有十分重要的意义。目前,对于动态模量的研究试验方法很多。两点弯曲(two-point bending)试验方法对试件的作用既有弯拉也有剪切,比较符合路面结构的实际受力状态。本文参考欧洲标准,采用法国M2F梯形梁设备对沥青混合料进行两点弯曲试验研究。并与SPT(Simple Performance Tester)动态模量试验方法进行了比对研究。首先在调查了国内外动态模量研究现状的情况下对动态模量的概念进行了阐述,对动态模量的室内外试验研究方法做了梳理;对沥青混合料的粘弹性原理、时温等效、主曲线等进行了介绍。采用M2F梯形梁设备进行动态模量试验,在不同的温度、荷载频率和应变水平下对四种SAC16级配的沥青混合料进行了室内试验研究。分析了动态模量的影响因素,包括温度、频率、沥青材料、级配等,绘制了动态模量的主曲线;将应变水平作为影响动态模量的影响因素,回归了动态模量二元方程表达式,绘制了主曲面,发现应变水平是影响沥青混合料动态模量的重要因素。得到了这几种常用沥青混合料的动态模量值范围。使用SPT对沥青混合料进行了动态模量试验,分析了动态模量的影响因素,绘制了动态模量主曲线。基于两种试验方法的试验数据,从试验原理和操作过程出发,对M2F和SPT两种试验方法得到的动态模量进行比对分析,从而对两种试验方法进行评价:对以受压为主的上面层沥青混凝土材料建议使用SPT;对受弯拉作用为主的中下面层,建议使用梯形梁试验进行研究。
[Abstract]:Pavement structure is affected by various factors, such as vehicle, environment and so on. Whether it is vehicle load or temperature alternation, The asphalt mixture used in asphalt pavement is a typical viscoelastic material, and its mechanical properties are very sensitive to the change of temperature and frequency. The mechanical response under dynamic load and static load is very different. At present, dynamic analysis methods of pavement structure and pavement materials are widely used in the world. As an important design parameter, dynamic modulus has been incorporated into the design method of AASHTO-2002. Therefore, based on the reality of our country, it is very important to study the dynamic modulus of asphalt mixture. At present, it is very important to study the dynamic modulus of asphalt mixture. There are many research and test methods for dynamic modulus. The effect of two-point bending test method on the specimen is both flexural and shearing, which accords with the actual stress state of pavement structure. In this paper, we refer to the European standard. The two-point bending test of asphalt mixture was carried out by using French M2F trapezoidal beam equipment, and was compared with the dynamic modulus test method of SPT(Simple Performance Tester. Firstly, the present situation of dynamic modulus research at home and abroad was investigated. The concept of dynamic modulus is expounded. In this paper, the indoor and outdoor test methods of dynamic modulus are combed, and the viscoelastic principle, time-temperature equivalence and main curve of asphalt mixture are introduced. The dynamic modulus test is carried out with M2F trapezoidal beam equipment at different temperatures. Four kinds of asphalt mixtures with SAC16 gradation were tested at loading frequency and strain level. The influencing factors of dynamic modulus, including temperature, frequency, asphalt material and gradation, were analyzed, and the main curves of dynamic modulus were drawn. The strain level is taken as the influencing factor of dynamic modulus, and the expression of binary equation of dynamic modulus is regressed, and the principal surface is drawn. It is found that the strain level is an important factor affecting the dynamic modulus of asphalt mixture. The range of dynamic modulus of these common asphalt mixtures is obtained. The dynamic modulus of asphalt mixture is tested by SPT. The influencing factors of dynamic modulus are analyzed, and the main curve of dynamic modulus is drawn. Based on the test data of two kinds of test methods, the dynamic modulus obtained by M2F and SPT is compared and analyzed according to the test principle and operation process. Therefore, two test methods are evaluated: SPT is recommended for asphalt concrete materials under compression, and trapezoid beam test is recommended for the middle and lower layers under flexural tension.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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