【作者】 雷超旭；

【导师】 王端宜；

【作者基本信息】 华南理工大学 ， 结构工程， 2010， 博士

【摘要】 随着我国预防性养护技术的不断发展,各种路面处置措施应用也越来越广泛,由于开展高速公路维修和预防性养护的系统研究的周期比较短,相关工艺和技术还仅仅处于学习、引进和模仿的初级阶段,而套用国外现成的路面处置措施并不适合我国实际情况。与此同时,多年来国内外道路科技界偏重于路面结构承载能力方面的研究,对路面的功能性损坏,以及由此带来的对结构性损坏的影响重视不够,而且缺乏必要的经验和数据储备。这其中,最突出的问题是缺乏适宜而有效的路面表面功能评价方法和手段。由于试验条件的限制,以往的路面表面处置相关研究很难对路面性能影响因素(环境、材料、工艺)和路面性能指标进行有效控制和定量评价,仅由承包商从商业利益的角度提出一些指标,显然这些指标缺乏科学性,并不能适应路面工程实际需要,从而无法很好地指导实际施工及质量评价,致使一些工程固有问题如雾封层抗滑、碎石封层降噪等的研究停滞不前,无法得到彻底解决。因此,有必要对现有路面预防性养护措施性能评价进行系统的研究,以完善表面处置型养护材料的应用,推动预防性养护技术的发展。本研究的目的是:优化路面性能指标评价体系,探讨封层处置后路面性能衰变规律,优化施工工艺,为路面表面处置方式的定量评价以及新技术和新材料的开发奠定良好的基础。论文的主要工作和创新成果如下:分析国内外现有各类加速加载试验机的特点和作用机理,结合机械原理,设计开发出主驱动轮式路面材料加速加载试验系统,主要用于路面表面功能的评价和研究。对试模进行改进,通过几何演算,指出传统的弧形碾压板与开发的试模并不匹配,而采用直板碾压是适宜的。分析不同工况下轮胎与路面的摩擦作用机理,指出主驱动方式最宜用于加速加载试验。分析汽车行驶时的全受力状况,指出圆周类的加速加载方式如环道试验并不十分符合实际状况,而只有轮胎行驶方向与路面中心线方向相一致时,才能真正地进行模拟试验。基于所开发的加速加载系统,提出路面表面功能相关测试方法、规程,对各试验条件和参数作出具体规定,确保试验结果的稳定、可靠。主要对路面摩擦和噪音两种功能进行测试和评价。试验发现荷载对摩擦系数的影响最大,其次是胎压和速度,温度在两种工况下的作用基本上不明显;另外,湿润状况下的摩擦系数总是低于干燥状况的,因此雨天行车危险系数更高。噪音测试结果表明速度对噪声的影响较大,回归方程的相关系数达到0.913。通过对获得的频谱图进行分析,发现轮胎/路面噪音的峰值出现在800Hz~1000Hz的范围内。基于逆向工程的思想,提出路面逆向设计概念并重塑旧沥青路面,发现重塑路面与原路面具有较高的相似度,而且相似度随加速加载次数的增加而增大;对表面实时封层处置,系统的熵值变大,表明表面处置的结果是使得不同系统或系统内部子系统之间功能更加趋于一致,使整体结构更加稳定。重点对雾封层类养护措施进行加速加载试验研究,得到结论有:(1)通过研究Do-Nothing条件下路面性能的衰减情况,发现各指标的衰减近似符合“S”型函数特征,并得到拟合方程,相关系数均在0.9以上;(2)选定四种材料用量对重塑路面进行封层处置,将测试结果与未处置(通过曲线拟合得到)时相比,根据计算所得性能跃迁率,发现0.5kg/m2的用量效果最好,同时也发现后处理即撒砂的工艺比仅仅涂刷沥青得到的路面性能效果更好,平均性能跃迁率高50%;(3)雾封层工后适宜地撒砂能够提高路面抗滑力,对撒砂工艺及作用机理进行深入的探讨,研究砂的粒径、撒布量、材质和棱角性对路面性能的影响。试验结果表明,1.18mm的砂效果最好,用量以0.5kg/m~2左右为宜,考虑到耐久性、表面美观和价格因素,推荐采用辉绿岩、玄武岩作为撒砂石料。研究还发现,天然砂(即河沙)由于表面多圆滑,与沥青的粘结力弱,撒布效果较差,甚至有可能带来负面作用(滚珠效应),而且颗粒越大,这种负作用越明显,因此,不推荐采用天然砂对雾封层进行后处理。更多还原

【Abstract】 With the continuous development of our country’s preventive maintenance technology, kinds of pavement treatment measures are widely applied. Foreign ready-made pavement treatment measures do not fit the actual situation in China, because the cycle of system study of carrying out highway maintenance and preventive maintenance is too short, and related processes and technologies are still at the initial stage of learning, introducing and imitating. In the meanwhile, domestic and international road sector emphases on bearing capacity of pavement structure in past years, but functional damage to the road and the resulting impact on the structural damage are paid insufficient attention to. In addition, it is lack of the necessary experience and reserves data and related research methods. The outstandiang problem is that there are always not appropriate and effective pavement surface functional evaluation methods. The indicators, raised by contractors from the standpoint of commercial profits, are so lack of scientificity that they are not suitable for actual projects and for construction and quality assessment, which induces that many inherent problems such as skid resistance decline after fog seal, noise deduction of chip seal and so on have never been figured all out. Therefore it is necessary to improve and optimize existing pavement preventive maintenance measures and to better the application of maintenance materials on surface treatment and to improve the development of preventive maintenance.The purpose of this study is to optimize evaluation system of pavement performance evaluation system, determine pavement performance attenuation laws and optimize construction technology, laying the foundation for quantitatively evaluating pavement surface treatment modes and developing new skills and technologies. The main work and innovation are concluded as follows:The feature and mechanism of current accelerated loading test machines in china and abroad are analyzed, and a new type of main-drive-wheel pavement surface material accelerated loading test system is designed and exploited according to mechanical principles, as well as the test molds, which will be mainly applied on evaluation research of pavement surface functions. Then geometric calculation is carried out, which indicates that the traditional arc press plate doesn’t match with the exploiting test models, while a straight plate is appropriate.The friction effect mechanism between the tire and pavement is analyzed under different working conditions, which concludes that the initiative drive-wheel model is most suitable to the accelerated loading test. In addition, by analyzing the complete stress situation when the car is moving, it is indicated that the cycle type accelerated loading models such as circular track test is not very consistent with practical situation. The simulation test can be done only when the tire ran direction is coincidence with the direction of the pavement center line.Based on the new accelerated loading system, corresponding test methods and regulations are prescribed and experimental conditions and parameters are determined to ensure the stability and reliability of test results. Two functions pavement friction and noise are tested and evaluated. It is found that load affects pavement friction coefficient most, followed by tire pressure and speed, but the influence of temperature is feeblish. In addition, the friction coefficient of moist pavement is always lower than that of dry pavement, so it is more dangerous to travel in rain days. The result of noise test shows that speed greatly influences tire/pavement noise, and the correlation coefficient of the regression equation reaches 0.913. According to the frequency spectrogram, the peak value of tire/pavement noise lies in the spectrum 800Hz~1000Hz.Based on the idea of reverse engineering, the concept of pavement converse design is proposed, and old asphalt pavements are remodeled. The results show that remodeling pavement has high similarity to the original pavement, and the similarity gets better with the time of accelerated and loading test. The entropy of pavement skid resistance raises after surface treatment, indicating that pavement maintenance tends to unify each subsystem and make the function of the whole structure more stable.According to fog seal treatment research by accelerated loading test, important achievements are scored as follows:(1) The attenuation of pavement performance under‘Do-Nothing’conditions is reviewed, and the indicators are found to be consistent with‘S-type’function characteristics. And equation are fitted with correlation coefficients higher than 0.9.(2) Four different dosages of asphalt materials are used on remold pavement, the jump rate of pavement performance is calculated by comparing test results with untreated pavement, concluding that the best dosage is 0.5kg/m2. In the meanwhile, performance of pavement post-treated with sand spray is better than brushing asphalt only, and the average performance jump rate increased by 50%.(3) After fog sealing, sanding process can increase the pavement anti-slide performance. Sanding process and mechanism are discussed, and factors, such as sand particle size, spreading volume, quality, angularity which could affect pavement performance, are focused on. Ii is concluded that sand with 1.18mm particle size is the best choice, and the suitable dosage is about0.5kg/m2. Diabase and basalt are good for spraying considering the durability, surface vision and price. It is also found that natural sand with smooth surface is weak in bonding with the asphalt, leading to negative results, for example roll ball effect. Besides, it may even cause negative effects, which will get more serious with larger particles. Therefore, natural sand is not recommended to be used for post-processing of fog sealing.更多还原