贵州高海拔地区沥青路面结构与材料适应性研究

发布时间：2018-04-29 22:22

  本文选题：沥青路面 + 高海拔地区　； 参考：《哈尔滨工业大学》2015年博士论文

【摘要】：云贵高原及其周边地区为主的高海拔地区,地处于我国西南部,具有冬季气温低、日温差大、年温差小、日照长、辐射强、干湿季分明、多大风等气候特点。该区域的沥青路面常出现过早老化、开裂等病害。由于高海拔地区半刚性沥青路面反射开裂现象的普遍性与严重性,该路面类型在高海拔地区的适用性已经受到人们的质疑。针对贵州高海拔地区高速公路的恶劣气候条件、交通荷载特点和使用要求,从路面结构和路面材料两方面系统开展高海拔地区沥青路面行为特性与设计方法研究,以期从理论上和应用上提出合理的高海拔地区沥青路面结构与材料设计方法,以弥补现行设计规范在高海拔地区应用中的不足。首先介绍了高海拔地区常规沥青混合料室内试验评价,以及性能优良、适用于高海拔地区的纳米改性沥青及纤维沥青混合料性能的试验研究。结果表明:AC-13偏近中值并增加沥青含量较为适合高寒地区环境,条件允许时可以进一步增加油石比,以满足更高的水稳定性,低温抗裂性和抗疲劳性的标准;采用更高标号的沥青可以显著改善沥青混合料的低温抗裂性,沥青面层厚度对开裂的影响不如路基和沥青材料的影响显著;掺入纤维后,混合料的性能有大幅度提升,其中聚酯纤维和福塔纤维表现明显优于木质素纤维。为进一步探讨防水抗裂功能层这一新型沥青混合料的路用性能,采用A-70沥青和AC-5中值级配、AC-5下限级配(粗级配)以及AC-10中值级配,重点研究矿料级配对防水抗裂功能层的水稳定性、低温抗裂性等路用性能的影响,确定防水抗裂功能层适宜采用的级配类型。并通过汉堡车辙试验评价级配与油石比对混合料水稳定性能的影响。与Strata应力吸收层相比,AC-10沥青混合料更适宜作为防水抗裂功能层。为了合理地检测各种路面材料的抗裂缝能力,提出一种新型的模拟反射裂缝发生机制的试验仪器(Overlay Tester试验),希望以此试验对各种材料的抗裂性及抗疲劳表现进行评价,并对现有的配合比设计方法提出改进。为兼顾沥青混合料的高温抗变形能力、水稳定性能和低温抗裂能力,提出直接依靠汉堡车辙试验和Overlay tester试验结果的沥青混合料配合比设计流程。提出了两种路面结构建议,即倒装复合基层结构和防水抗裂功能层结构,采用数值模拟方法对这两种路面结构力学行为进行了分析。结果表明:倒装复合式基层结构在荷载作用下,面层底面出现拉应力,且随着轴载的增大,面层底面的拉应力近似成线性递增;级配碎石层底面始终处于受压状态,基层底面拉应力明显小于传统的半刚性基层结构;设置防水抗裂功能层可以延缓裂缝的产生和发展有显著作用;防水抗裂功能层对车辙的贡献不大,路面不会因设置了防水抗裂层而产生比没有设置时更大的车辙。最后,为了使设计的路面结构更合理、更可靠,先采用我国现行的沥青路面设计规范对几种不同的沥青路面结构进行设计,然后采用预测轴载疲劳累计损伤方法(Miner法则)对上述路面结构进行验证。结果显示:厚沥青层的半刚性基层路面结构中各结构层具有较小的疲劳损伤因子,从疲劳寿命的角度考虑,这种结构形式是最优的。
[Abstract]:The high altitude areas of Yunnan Guizhou Plateau and its surrounding areas are located in the southwest of China, with low temperature in winter, large diurnal temperature difference, small annual temperature difference, long sunshine, strong radiation, clear dry and wet season, and large wind and other climatic characteristics. The asphalt pavement in this region often appears premature aging, cracking and other diseases. Due to the reflection of semi-rigid asphalt pavement in high altitude area The applicability of the pavement type in high altitude area has been questioned by people. In view of the harsh climate conditions, traffic load characteristics and use requirements of highways in high altitude areas of Guizhou, the behavior characteristics of asphalt pavement behavior in high altitude areas are carried out from two aspects of pavement structure and pavement material. The design method is studied in order to make a reasonable design method of asphalt pavement structure and material in high altitude area in order to make up the shortage of current design standard in high altitude area. First, it introduces the indoor test evaluation of conventional asphalt mixture in high altitude area, and its performance is excellent, which is suitable for high altitude area. Experimental study on the properties of nano modified asphalt and fiber bitumen mixture. The results show that the near middle value of AC-13 and the increase of asphalt content are more suitable for the environment in high and cold regions. When conditions permit, the oil stone ratio can be further increased to meet the standards of higher water stability, low temperature crack resistance and fatigue resistance; the higher marking asphalt can be displayed. In order to improve the crack resistance of asphalt mixture at low temperature, the effect of the thickness of the asphalt surface on the cracking is not as significant as that of the subgrade and the bituminous material. After adding the fiber, the performance of the mixture is greatly improved, and the performance of the polyester fiber and the foff fiber is obviously superior to the lignin fiber. The pavement performance of the mixture, using the A-70 asphalt and AC-5 middle value gradation, the AC-5 lower limit gradation (coarse gradation) and the value gradation of the AC-10, focuses on the study of the water stability of the waterproof and crack resistance functional layer and the influence of the low temperature crack resistance and other road properties, and determines the suitable type of gradation for the waterproof and crack resistance functional layer. Compared with the Strata stress absorption layer, AC-10 asphalt mixture is more suitable to be a waterproof and anti cracking function layer compared with the Strata stress absorption layer. In order to reasonably detect the anti crack ability of various pavement materials, a new type of test instrument (Overlay Tester test) for simulating the reflection crack initiation mechanism is proposed. To evaluate the anti cracking and anti fatigue performance of various materials, and to improve the existing mix design method. In order to take into account the high temperature resistance to deformability, water stability and low temperature crack resistance of asphalt mixture, the mixture of asphalt mixture, which is directly dependent on the hamburger rut test and the results of Overlay tester test, is put forward. Compared with the design process, two kinds of pavement structure suggestions are proposed, that is, the inverted composite base structure and the waterproof and anti cracking function layer structure. The numerical simulation method is used to analyze the mechanical behavior of the two kinds of pavement structures. The results show that the reverse loading composite base structure has tensile stress at the bottom surface of the surface under the load action, and with the increase of the axle load, the surface is increased. The tensile stress of the bottom surface is approximately linearly increasing, and the bottom surface of the graded crushed rock is always in the compression state. The tensile stress at the bottom of the base is obviously smaller than the traditional semi-rigid base structure, and the waterproof and anti cracking functional layer can delay the emergence and development of the cracks. The contribution of the waterproof and anti cracking energy layer to the rutting is not great and the pavement will not be set up. In order to make the design of the pavement structure more reasonable and more reliable, in order to make the design of the pavement more reasonable and more reliable, the design of several different asphalt pavement structures is first designed by the current asphalt pavement design standard of our country, and then the prediction of the cumulative damage method of axle load fatigue (Miner rule) is used for the above pavement structure. The results show that the structural layers in the semi-rigid base of the thick asphalt layer have smaller fatigue damage factors. Considering the fatigue life, this kind of structural form is the best.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U416.217
，

本文编号：1821835