【作者】 刘燕燕；

【导师】 凌天清；

【作者基本信息】 重庆交通大学 ， 道路与铁道工程， 2013， 博士

【摘要】 在我国公路建设中,以水泥稳定材料或石灰粉煤灰稳定材料为主的半刚性基层和底基层是目前路面结构的主要形式,但裂缝问题日益突出已成为该结构主要缺陷。纤维增强乳化沥青应力吸收层以应力吸收和扩散能力强、抗裂性能好,防水性能好,稳定性高,施工快捷,便于回收利用,在国外被广泛的作为基层与面层之间的应力吸收层使用。目前对这项技术研究大多数只停留在工艺介绍上,机理研究较少,缺乏对材料的优选,材料用量基本是按照经验值,且不同研究者推荐的用量范围差异较大,没有系统的配合比设计方法,施工中缺乏过程控制指标等。本文依托重庆、江苏省交通科技研究项目对该技术进行了深入的理论和试验研究。论文从复合材料界面细观力学角度,通过接触角的测定,研究不同纤维品种与乳化沥青的界面粘附功；基于应变损耗功能和原理,分析比较不同纤维品种与乳化沥青复合材料的应变损耗能,提出纤维优选方案。利用红外光谱分析不同纤维对乳化沥青特征官能团的选择性吸附,提出纤维表面改性方法。应用断裂力学基本原理,采用有限元数值分析研究铺设纤维增强乳化沥青应力吸收层后对三种开裂模式(反射裂缝,Top-down裂缝,对接裂缝)的阻裂效果。深入研究了应力吸收层模量,厚度,反射裂缝宽度,层间接触条件,沥青混合料加铺层厚度对抗裂性能的影响。从断裂的能量角度分析纤维增强乳化沥青应力吸收层组成材料在不同因素水平下的断裂能,得出影响断裂能的主次因素和最佳材料用量组合,对比不同应力吸收层断裂能大小。系统研究影响应力吸收层路用性能指标(最大弯曲力,最大挠度,层间剪切力,层间粘结力,抗反射裂缝作用次数)的主要因素和最佳材料用量组合。讨论应力吸收层厚度和加铺层厚度对复合路面结构抗反射裂缝性能影响。动态监控铺设不同应力吸收层后,裂缝在复合路面结构中的发展情况,对比不同应力吸收层对裂缝扩展速度的影响；建立裂缝发展不同时期(初期、中期、后期)与各个力学指标的灰色关联度,确定与裂缝发展速度关联度最大的相关指标,并以此作为应力吸收层配合比设计的主要参数。基于最大功能和原理推导最佳纤维乳化沥青用量比,考虑碎石和半刚性基层对乳化沥青吸收率,得出配合比设计的半经验半理论方法。基于裂缝动态发展规律与力学指标关联度分析结果,以最大弯曲力、层间剪切力和断裂能作为主要设计参数指标,提出配合比设计的试验方法。结合研究成果,介绍纤维增强乳化沥青应力吸收层的配合设计工程应用示例和施工控制要点。更多还原

【Abstract】 In the highway construction in China, semi-rigid base and subbase with cement stabilized material or lime and fly ash stabilized material is the main form of pavement structure of highway. At present, the crack problem increasingly has become the main defect of this structure. Fiber reinforced emulsified asphalt stress absorbing layer have good performance of stress absorbing, good anti-cracking, good waterproof performance, high stability, fast construction, convenient for recycling, in foreign countries has been widely used as stress absorbing layer between base and surface. At present this technology only stay in introducing the construction process, lacking theoretical research and selection of material, material consumption is largely basic on experience value, the amount range of different researchers recommend is bigger, does not have mix design method, lacking of process control index of construction, etc. In this paper, carrys out theory and experimental study in-depth of this technology base on the Chongqing and Jiangsu Province Traffic Science and Technology Projects.This paper from the micromechanics angle of composite material, by measuring the contact angle, obtains the adhesion work of the different fiber and emulsified asphalt, uses the principle of work and energy to calculate and compare strain and losing energy between different fibers and emulsified asphalt, makes fiber optimization scheme. Analysis of different fibers selective absorbing characteristic functional groups of emulsified asphalt by infrared spectrum, provides methods for the fiber surface modification.Application of basic principles of fracture mechanics, using finite element numerical analysis of anti-cracking effect after laying fiber reinforced emulsified asphalt stress absorbing layer on three kinds of cracking model (reflection crack, Top-down crack, docking crack). In-depth study the stress absorbing layer modulus, thickness, the reflection crack width, interlayer contact conditions and thickness of asphalt mixture overlay influence on crack resistance effect.From the fracture energy point of view, analysis fracture energy of fiber reinforced emulsified asphalt stress absorption layer material at different levels, and factors affecting the fracture energy and the best amount of material combination, compare fracture energy of the different stress absorbing layers. A comprehensive analysis of the main factors and the best dosage combination, which impact the other mechanical index (maximum bending force, the deflection, shear force, interlayer adhesive force, cycle fatigue loading times). Discuss about the influence of stress absorbing layer thickness and overlay thickness on the reflective cracking resistance performance of composite pavement structure.Dynamic monitor cracking development in composite pavement structure after laying different stress absorbing layer, comparing cracking development of the different stress absorbing layers; establishment grey relational degree of crack development in different periods (early, mid, later) with all mechanical index, according to the correlation value, determine relevant parameters, which have the maximum correlation degree with cracking development velocity, and as a main design parameters for stress absorbing layer.According to the maximum work and energy principle obtain optimal fiber asphalt content ratio, base on gravel and semi-rigid base absorption rate of emulsified asphalt mixture, puts forward the semi-empirical design method. According to the law of crack development and mechanical index correlation analysis results, use the maximum bending force, shearing force and fracture energy as the main mechanical parameters, put forward the test design method. According to the research results, example the fiber stress absorbing layer design application and the main construction controlling points.更多还原