【作者】 张鑫；

【导师】 张肖宁； 冯德成；

【作者基本信息】 哈尔滨工业大学 ， 道路与铁道工程， 2011， 博士

【摘要】 因具有良好的行车舒适性和使用性能,沥青路面成为我国高速公路路面的主要形式。作为一种温度敏感性材料,高温会导致沥青混合料的劲度模量降低,在车辆荷载的反复作用下,容易出现车辙、拥包、推移等永久性变形。这些病害形式严重地危害行车安全,缩短道路的使用寿命。传统的解决高温问题的方法是使用高性能的沥青、优质的集料或是骨架密实型沥青混合料,这些方法增加了道路工程造价和施工难度,都被动地接受了过高的路面温度。而且有时即使应用了这些措施,沥青路面的高温病害也没有得到彻底解决。过高的路面温度是造成这些病害的主要原因。通过合理的材料选择和结构设计,可以实现路面结构的热反射与热阻功能,主动地降低路面结构的温度场,在不增加工程造价的基础上,控制或减少路面的高温病害的发生。同时,伴随着我国城市化进程,城市热岛效应成为了一个日益严重的环境问题,既危害城市居民健康,又造成大量能源消耗。在城市道路铺装上应用热反射和热阻技术,可以减缓城市热岛效应。本文通过分析路面温度场的影响因素,研究了热反射与热阻技术的降温机理和技术可行性;开发了路用热反射涂层材料,并测试了降温效果和路用性能;设计了具有热阻功能的磨耗层材料,综合考虑隔热效果和路用性能,确定了合理的材料配比;综合考虑多孔沥青混合料的阻热效果和路用性能,确定了适宜的空隙率范围;通过热反射试验路的修筑和观测,总结了热反射涂层的关键施工技术。主要研究内容和成果概括如下:进行了热反射与热阻技术的降温机理及可行性分析。根据传热学的基本原理,从沥青路面的光热环境分析入手,采用ABAQUS有限元软件,建立沥青路面温度场的计算模型,采用实测的温度场数据校核模型的准确性。根据该模型对影响路面温度场的单因素分析可知,增加材料的反射率和发射率可以降低路面结构在各个时刻的温度;增加比热可以降低路面结构的最高温度;降低导热系数虽然会略微增加路表的最高温度,却可以较大幅度的降低路面在中面层以下的最高温度。对各因素对沥青路面温度场的影响情况进行了敏感度分析,为通过材料选择和结构设计控制过高的路面温度提供了理论指导。而后选取5种热物参数具有代表性的材料,分析热物参数对路面温度场的综合影响。分析了车辙病害的成因,认为中面层温度过高和剪应力集中是产生车辙的主要原因。为应用热反射与热阻技术控制车辙病害和缓解热岛效应提供了理论基础。通过对现有道路建筑材料的热物性能分析,论证了在道路工程上应用热反射与热阻技术的可行性。设计了室内模拟太阳辐射试验系统和沥青混合料热物参数的测试试验平台。室内模拟太阳辐射实验系统可以定量的评价所开发的热反射与热阻材料的降温或隔热效果。按照等效辐射原则确定了试验系统的辐射时间和辐射强度。通过与室外试验结果相对比,验证了系统的稳定性和准确性。设计了基于常功率平面热源法的热物参数测试方法,测试具有热阻功能的沥青混合料的热物参数,定量的评价材料的阻热性能。开发了基于热反射技术的路用热反射涂层材料。通过分析热反射涂层的降温机理,综合考虑反射率、眩光效果、使用寿命和造价,选择成膜物、助剂和颜填料,开发了适合路用的热反射涂层材料。该涂层为水溶性材料,具有造价低、施工方便、对环境无污染、养生时间短等特点。兼顾材料的降温效果和路用性能,确定了综合性能最优的热反射涂层材料配比。开发了基于热阻技术的热阻磨耗层材料。通过选用导热系数较小的陶砂和陶粒代替部分集料,设计了具有阻热功能的陶砂热阻磨耗层和陶粒热阻磨耗层材料。分别测试了材料的热物参数、阻热效果和路用性能,综合考虑阻热效果和路用性能,确定了合理的陶砂和陶粒掺量。研究了空隙率对多孔沥青混合料隔热效果、热物参数和路用性能的影响,探讨了兼顾阻热效果和路用性能要求的最佳空隙率范围。进行了热反射涂层的施工关键技术研究。为便于热反射涂层的大规模推广应用,开发了自动化程度较高的热反射涂层洒布车,实现涂层材料的快速、高效施工。通过试验路观测热反射涂层的降温效果、路用性能和使用寿命。更多还原

【Abstract】 Asphalt pavement is widely used in our country because of driving comfort and performance. Hot mixture asphalt is sensitive to temperature. High temperature decreases modulus of HMA. With the effect of vehicle load time and again, permanent deformation such as rut, folding and slippage occur. These would decrease driving safety and shorten road work life. Traditional measures solve these diseases by using high quality asphalt and aggregate or choosing skeleton dense structure for HMA. All these increase road engineering cost and construction difficulty. The over high road temperature is accepted passively. Even all these measures are taken, high temperature diseases are not solved completely. Main reason leading this is over high temperature of road structure. By reasonable materials selection and structure design, the temperature of road can be decreased by using heat reflection and thermal resistance technology and reduce high temperature diseases at a certain extent without increasing road cost. At the same time, with the process of urbanization in our country, the Urban Heat Island effect becomes a more and more serious environment problem. The UHI effect harm citizen health and increase power demand for cooling in summer. Application heat reflection and thermal resistance technology in city pavement can mitigate UHI effect.In this paper, factors effecting road structure temperature field are analyzed. The decreasing temperature mechanism and feasibility of heat reflection and thermal resistance technology are researched. The heat reflection coatings are developed. Decreasing temperature effect and road performance are tested. Thermal resistance wearing course are developed. The materials compose is determined by considering thermal resistance and road performance. The optimum void range for porous asphalt mixture is suggested by researching thermal resistance effect and mechanics performance. Construction technology of heat reflection coating is provided by construction and observation of experimental road. All research works in the paper are outlined as following:Decreasing temperature mechanism and feasibility of heat reflection and thermal resistance is analyzed. Based on heat transfer theory and asphalt pavement light-heat environment, a temperature field computing model of asphalt pavement is built by ABAQUS finite element software. The model is verified by field test results. According to analysis of single factors influence on temperature field, increasing reflectivity and emissivity can decrease temperature at anytime. Increasing specific heat can decrease temperature at high temperature time. Decreasing thermal conductivity can increase surface temperature slightly but decrease temperature under middle layer largely. Sensitive analysis about thermal properties on temperature field is carried out. Those results can direct materials choosing and structure design. Then five materials with typical on thermal properties are chosen to research the thermal properties influence on temperature field. The results provide theory base of using heat reflection and thermal resistance technology to decrease rut and mitigate UHI effect. The feasibility of heat reflection and thermal resistance technology is discussed by researching construction materials thermal properties.Indoor simulation solar radiation system and asphalt concrete thermal properties experiment are developed. Based on radiation energy equal principle, the radiation time and intense is determined. Decreasing temperature effect can be evaluated quantitatively. Precision and stability of the developed system are tested by field results. Test method of asphalt concrete thermal properties is designed based on plane-source method with constant heating rate. Thermal resistance effect is evaluated by thermal properties.Heat reflection coatings for road are developed based on heat reflection technology. Film-formers, complex and pigments are determined to conform heat reflection coating by researching decreasing temperature mechanism, reflectivity, glare effect, work life and cost. The materials are water-soluble, low cost, easy construction, no pollution and short curing period. The best heat reflection coating is determined by considering decreasing temperature and road performance.Thermal resistance wearing course materials are developed based on thermal resistance technology. Sintered clay and crushed ceramic with smaller thermal conductivity are taken as partial aggregate to form thermal resistance wearing course materials. Test the thermal properties, decreasing temperature effect and road performance. The reasonable dosages of sintered clay and crushed ceramic are determined by considering thermal resistance effect and road performance. The reasonable void range of porous asphalt mixture is discussed by researching different void decreasing temperature effect and road performance.Key construction technology of heat reflection coating is researched. Heat reflection sprayer with high automatic is developed for fast and effective construction. Decreasing temperature effect, road performance and work life are researched through experimental road.更多还原