橡胶沥青低温劲度模量的实验研究

发布时间：2018-05-16 01:47

本文选题：橡胶沥青 + 弯曲试验　；参考：《吉林大学》2015年硕士论文

【摘要】：沥青混凝土路面的低温开裂破坏，尤其在寒冷地区，是沥青路面主要形式之一。我国北方地区冬季寒冷漫长，新铺设的沥青路面往往在通车很短时间后，路面就会出现分布较为规律的横向裂缝。裂纹周围是路面破坏的薄弱区域，雨水渗入后，不能及时排空，加剧冻涨、冻融发生，进而引发沥青混合料的剥落、松散、坑洞等破坏问题，导致路面出现早期破坏，使得路面的实际使用寿命大幅低于设计寿命。为解决路面的低温开裂破坏，国内外的学者作了大量的研究。20世纪50年代，荷兰学者Van del Poel提出了劲度模量的概念，作为时间和温度的函数，能够较好的反应作为典型粘弹性材料的沥青的受力与变形的关系，一经提出便受到了道路工程界学者们的高度重视。本文首先研究了橡胶沥青的改性机理，通过室内试验测试了橡胶沥青的针入度、软化点、弹性恢复、粘附性等基础指标，，根据几种基础指标试验对比90#基质沥青和橡胶沥青并对其低温性能进行了分析研究。其次，通过对劲度模量定义的研究，自行设计能够测试沥青及胶浆低温劲度模量的三点弯曲试验。对沥青及胶浆小梁在不同低温下的荷载、变形等数据进行了处理分析，研究分析了橡胶沥青及胶浆的应变随时间变化的规律、变形随温度变化的规律，并与90#基质沥青及胶浆进行了对比分析。在研究沥青及胶浆低温受力与变形特性的基础上，进一步研究了橡胶沥青及胶浆低温劲度模量随时间和温度的变化规律，同样与90#基质沥青及胶浆进行了对比分析。在试验研究过程中还考虑不同掺量橡胶粉、载荷作用时间、环境温度等因素对沥青及胶浆的变形性能和劲度模量的影响。说明了温度对于劲度模量的影响最为关键。最后，通过不同低温条件下的橡胶沥青混合料劈裂试验，对橡胶沥青混合料的低温性能进行了评估分析，分别研究了橡胶沥青混合料的劈裂强度、破坏应变和破坏劲度模量随温度变化的规律，并与90#基质沥青混合料进行了对比分析。同时，并采用沥青劲度模量求取混合料劲度模量的H-K法对试验所得沥青混合料低温劲度模量结果进行了对比评价，验证了试验方法的有效性。
[Abstract]:Low temperature cracking and damage of asphalt concrete pavement, especially in cold area, is one of the main forms of asphalt pavement. The winter is long and cold in the north of our country. After the new asphalt pavement is opened to traffic for a short time, the pavement will appear the transverse crack that distributes more regularly. There is a weak area of pavement damage around the crack. After Rain Water infiltration, it can not be emptied in time, which will aggravate the freezing and thawing, and lead to the spalling, loosening and pothole of asphalt mixture, which will lead to the early destruction of the pavement. The actual service life of pavement is much lower than that of design. In order to solve the low temperature cracking and failure of pavement, scholars at home and abroad have done a lot of research. In the 1950s, Dutch scholar Van del Poel put forward the concept of modulus of stiffness as a function of time and temperature. The relationship between stress and deformation of asphalt, which can be used as a typical viscoelastic material, has been attached great importance by road engineering scholars once it is put forward. In this paper, the modification mechanism of rubber asphalt was studied. The penetration, softening point, elastic recovery and adhesion of rubber asphalt were tested in laboratory. The low temperature properties of 90# base asphalt and rubber asphalt were studied and compared according to several basic indexes. Secondly, a three-point bending test is designed to measure the low temperature stiffness modulus of asphalt and mortar by studying the definition of the modulus of the degree of stiffness. The data of load and deformation of asphalt and mortar trabeculae at different low temperatures are processed and analyzed. The law of strain variation with time and deformation with temperature of rubber asphalt and mortar are studied and analyzed. The results were compared with 9 0# base asphalt and mortar. On the basis of studying the low temperature stress and deformation characteristics of asphalt and mortar, the variation of low temperature stiffness modulus of rubber asphalt and mortar with time and temperature is further studied, and also compared with 90# base asphalt and mortar. The effects of rubber powder, loading time and ambient temperature on the deformation properties and stiffness modulus of asphalt and mortar were also considered. The effect of temperature on modulus of stiffness is the most important. Finally, through the split test of rubber asphalt mixture under different low temperature conditions, the low temperature performance of rubber asphalt mixture is evaluated and analyzed, and the splitting strength of rubber asphalt mixture is studied respectively. The variation of failure strain and modulus of failure stiffness with temperature was compared with that of 90# base asphalt mixture. At the same time, the H-K method is used to calculate the stiffness modulus of asphalt mixture. The results of low temperature stiffness modulus of asphalt mixture are compared and evaluated, and the validity of the test method is verified.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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