水泥乳化沥青混合料收缩性能研究

发布时间：2018-06-03 08:18

本文选题：水泥乳化沥青混合料 + 收缩系数　；参考：《长安大学》2014年硕士论文

【摘要】：水泥乳化沥青混合料收缩性能主要受组成材料和外界环境温度影响，尤其是水泥和乳化沥青结合料，及其组成的复合胶浆与集料的相互作用对收缩性能有直接影响。为研究在各个影响因素下，混合料收缩性能的变化情况，本文通过改变水泥、乳化沥青的含量以及矿料级配类型，对混合料进行干燥收缩、温度收缩等测试试验，测得各个龄期时混合料收缩系数的变化规律，并探讨变量因素对收缩性能的影响机理。结合光学显微镜、扫描电镜(SEM)和X射线衍射(XRD)等微观手段观测水泥乳化沥青胶浆的微观结构，及水泥-乳化沥青胶浆在混合料中的存在状态，分析其影响机理。试验数据及相关微观图表明：随着龄期的增长，混合料的收缩率随着水泥用量增加而减小，随着乳化沥青用量增加而增大；水泥乳化沥青混合料中矿粉起填充作用，，水泥水化作用产生大量结构致密的结晶水化物，与破乳后的沥青相互交织，提高了混合料结构的致密性。而对于温度的影响，在不同降温区间，随着水泥含量的增加，混合料的收缩系数都减小；刚性材料水泥的加入减弱了混合料的柔性，温度敏感性降低，提高了胶浆的粘度。而表征沥青材料感温性能的粘度，也用来衡量混合料的劲度模量，并直接影响到混合料的温度应力及应变，从而决定了混合料的抗收缩开裂性能。文中分别采用了AC-5、AC-10、AC-13矿料级配，对比研究发现，粗级配的混合料中含有较多粗集料，其收缩性能好；而细级配的混合料中细集料多，密实度高，不利于温度应力的释放，温度收缩开裂性较严重。最后根据水泥乳化沥青混合料收缩行为产生的原因，提出了混合料的收缩模型，通过测得各个材料物性指标，进行收缩系数的验证，计算的结果与试验测得的数值接近。
[Abstract]:The shrinkage performance of cement emulsified asphalt mixture is mainly affected by composition material and ambient temperature, especially the interaction between cement and emulsified asphalt binder, and the interaction between composite mortar and aggregate. In order to study the change of the shrinkage performance of the mixture under various influence factors, the dry shrinkage and temperature shrinkage of the mixture were tested by changing the content of cement, emulsified asphalt and the type of aggregate gradation. The variation law of shrinkage coefficient of mixture at different ages was measured and the influence mechanism of variable factors on shrinkage performance was discussed. Combined with optical microscope, scanning electron microscope (SEM) and X-ray diffraction (XRD), the microstructure of cement emulsified asphalt slurry and the existing state of cement emulsified asphalt slurry in mixture were observed, and its influence mechanism was analyzed. The experimental data and related micrographs show that the shrinkage of the mixture decreases with the increase of cement content and increases with the increase of emulsified asphalt content, and the mineral powder plays a filling role in cement emulsified asphalt mixture. Cement hydration produces a large number of dense crystalline hydrates which interweave with asphalt after demulsification and improve the compactness of mixture structure. For the effect of temperature, the shrinkage coefficient of the mixture decreases with the increase of cement content in different cooling areas, and the flexibility of mixture is weakened and the temperature sensitivity decreases with the addition of rigid material cement, and the viscosity of mortar is improved. The viscosity of asphalt material is also used to measure the stiffness modulus of the mixture and directly affect the temperature stress and strain of the mixture, which determines the shrinkage and cracking resistance of the mixture. In this paper, AC-5 AC-10 AC-13 mineral aggregate gradation is adopted respectively. The comparison study shows that the coarse gradation mixture contains more coarse aggregate and its shrinkage performance is good, while the fine grained mixture has many fine aggregates and high compactness, which is not conducive to the release of temperature stress. The temperature shrinkage cracking is more serious. Finally, according to the reason of shrinkage behavior of cement emulsified asphalt mixture, the shrinkage model of the mixture is put forward. The shrinkage coefficient is verified by measuring the physical properties of each material, and the calculated results are close to the experimental values.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U414

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