【作者】 王静；

【导师】 张吉哲； 姚占勇；

【作者基本信息】 山东大学 ， 道路与铁道工程， 2023， 硕士

【摘要】 可溶盐的长期侵蚀会造成沥青胶浆-集料界面黏附性的降低,是影响沿海地区沥青路面服役寿命的重要原因。然而,可溶盐侵蚀下沥青混合料的微细观损伤机理及其引发的宏观力学性能衰变规律不清,导致无法准确揭示可溶盐侵蚀的本质特征。另外,沿海地区花岗岩储量丰富,但其呈酸性,与沥青黏附性差,若能将花岗岩就地取材应用于沥青路面,可有效决解高速路面优质石料短缺的问题。因此,本文以沥青胶浆-集料界面为重点研究对象,进行了沥青胶浆-集料界面水盐侵蚀损伤演变规律与性能提升研究。本文采用微观测试方法,研究了矿粉和集料的基本物理化学性质,并采用沥青胶浆宏观性能试验评价了沥青胶浆的流变性能和渗透特性;开发了动水压力模拟装置,设计了基于沥青胶浆膜厚度精确控制的沥青胶浆-集料试件制备方法与界面力学特性测试方法,基于此,提出了沥青胶浆-集料界面水盐侵蚀模拟方法;研究了沥青胶浆-集料试件在水盐侵蚀下界面力学指标衰变规律与可溶盐迁移规律、微观界面损伤规律,分析了界面力学指标衰变与可溶盐迁移、微观界面损伤的内在关系,探明了影响界面衰减规律的关键影响因素;基于界面力学定量测试方法,提出了花岗岩集料水盐侵蚀性能提升方法,并对花岗岩沥青混合料的服役耐久性进行了综合研究。主要结论如下:(1)玄武岩矿粉的比表面积和孔隙体积远大于石灰岩矿粉,使玄武岩胶浆吸附的结构沥青更多,玄武岩胶浆的渗透系数大于石灰岩胶浆,使水或盐溶液更易渗透进入其内部。(2)研发了能够产生正负压力交替作用的动水压力模拟装置,能够真实地模拟车辆荷载作用下沥青路面所承受的服役环境;开发了沥青胶浆-集料试件成型与测试方法,能够实现沥青胶浆膜厚度的精确控制,实现界面力学性能的准确定量测试。(3)采用宏细观相结合的方法,发现在水盐侵蚀条件下,盐溶液会逐渐进入沥青胶浆内部,产生孔隙与裂缝,并且盐结晶会产生膨胀应力,破坏沥青胶浆与集料的黏附作用,表现为力学性能的衰减。基于灰色关联分析法,得出孔隙体积、表观密度和比表面积是影响水盐侵蚀下界面强度的关键因素。(4)为改善界面的抗水盐侵蚀性能,采用抗剥落剂对界面进行改性,发现硅烷偶联剂KH-550和TR-500S能够显著提升沥青胶浆-集料的界面强度,并且使动水压力作用24 h后残留强度比提高40%之多,显著提升界面的水盐侵蚀特性,并且能够提升花岗岩沥青混合料的水稳定性和高低温性能。通过上述研究,揭示了水盐侵蚀下沥青胶浆-集料界面的力学性能衰减与微细观界面演变规律,提出了沥青胶浆-界面水盐侵蚀提升技术,有效改善了花岗岩沥青混合料的水稳定性与耐久性,将为沿海地区道路工程材料优选与改性提供科学依据,还将花岗岩集料的应用提供指导意见,具有重要的现实意义和推广价值。更多还原

【Abstract】 The long-term erosion of soluble salts can reduce the adhesion of asphalt mortaraggregate interface,which is an important reason for affecting the service life of asphalt pavement in coastal areas.However,the macro and micro damage mechanisms of asphalt mixtures under soluble salt erosion and the decay laws of their macroscopic mechanical properties are unclear,leading to the inability to accurately reveal the essential characteristics of soluble salt erosion.In addition,there are abundant reserves of granite in coastal areas,but it is acidic and has poor adhesion to asphalt.If granite can be applied to asphalt pavement using local materials,it can effectively solve the problem of shortage of high-quality stone materials for high-speed pavement.Therefore,this paper focuses on the study of moisture-salt erosion damage evolution and performance improvement at the asphalt mortar aggregate interface.In this paper,the basic physical and chemical properties of mineral powder and aggregate were studied using microscopic testing methods,and the rheological and permeability properties of asphalt mortar were evaluated using macroscopic performance tests.A hydrodynamic pressure simulation device was developed,and a method for preparing asphalt mortar-aggregate specimens and testing interfacial mechanical properties was designed to accurately control the thickness of asphalt mortar film.Based on this,a simulation method for moisture-salt erosion at the asphalt mortar-aggregate interface was proposed;the decay law of interface mechanical properties,soluble salt migration law,and microscopic interface damage law of asphalt mortar-aggregate specimens under moisture-salt erosion were studied.The internal relationships between interface mechanical properties,soluble salt migration,and microscopic interface damage were analyzed,and the key influencing factors affecting the interface mechanical properties were studied.Based on the quantitative testing method of interface mechanics,the anti-stripping agent for improving the moisture-salt erosion performance of granite aggregate was selected,and the mix design and road performance research of asphalt mixture were conducted.The main conclusions are as follows:(1)The specific surface area and pore volume of basalt mineral powder are much larger than that of limestone mineral powder,which makes the basalt mortar absorb more structural asphalt.The permeability coefficient of basalt mortar is greater than that of limestone mortar,making it easier for moisture-salt solution to penetrate into its interior.(2)A dynamic water pressure simulation device capable of generating alternating positive and negative pressure has been developed,which can truly simulate the service environment of asphalt pavement under vehicle loads.The method for forming and testing asphalt mortar-aggregate specimens has been developed,which can achieve precise control of the thickness of asphalt mortar film and accurate quantitative testing of interface mechanical properties.(3)Under moisture-salt erosion conditions,salt solution will gradually enter the interior of asphalt mortar,resulting in pores and cracks,and salt crystallization will generate expansion stress,damaging the adhesion between asphalt mortar and aggregate,which is manifested as attenuation of mechanical properties.Based on the gray correlation analysis method,it is concluded that pore volume,apparent density,and specific surface area are the key factors affecting the interfacial strength under moisture-salt erosion.(4)The silane coupling agents KH-550 and TR-500S can significantly improve the interfacial strength of asphalt mortar-aggregate,and increase the residual strength ratio by up to 40%after 24 hours of dynamic water pressure,significantly improving the moisture-salt corrosion characteristics of the interface,and improving the water stability and high and low temperature performance of granite asphalt mixture.This study reveals the attenuation of mechanical properties and the evolution of macro and micro interfaces of asphalt mortar-aggregate interface under moisture-salt erosion,and proposes a moisture-salt erosion enhancement technology for the interface,which will provide a scientific basis for the optimization and modification of road engineering materials in coastal areas.It also provides guidance for the application of granite aggregate,which has important practical significance and promotion value.更多还原