废旧玻璃在沥青混合料中的应用研究进展

Review on Asphalt Mixture Incorporating Waste Glass

近年我国公路建设迅速发展,2016年高速公路总里程达到13.10万公里,其中沥青路面占95%以上。沥青路面的建设使沥青和石料等自然资源大量消耗,给环境资源带来较大负担。为缓解道路建设对天然石料的消耗,国内外学者开展了固体废弃物在沥青混凝土中的回收再利用研究。与此同时,鉴于废旧玻璃的不断增多和处理方法的缺陷,寻求废旧玻璃的有效处理途径已是当务之急。利用废旧玻璃这种常见生活及工业废弃物替代部分天然石料进行沥青混凝土的制备则是有效的解决方法之一。已有研究表明,废旧玻璃破碎后具有耐磨、抗滑、反光、渗水性强等特性,替代部分集料制备废旧玻璃沥青混凝土作为面层,可一定程度改善路面耐磨、抗滑、透水等路用性能。当前,废旧玻璃在沥青混凝土中的应用面临一系列问题。废旧玻璃材料质脆,主要成分SiO2为亲水性材料,掺入后沥青混凝土的强度及耐久性受到一定程度的影响。废旧玻璃来源丰富,多为生活垃圾,其回收、筛选、破碎等处理过程复杂,在我国回收利用率较低,且道路工程中对原材料杂质含量要求较高,这就抬高了废旧玻璃回收利用的技术要求及成本。基于以上问题,研究者对废旧玻璃的工程特性和材料组成以及废旧玻璃沥青混凝土的路用性能和力学特性开展了进一步研究。研究结果表明,玻璃颗粒尺寸、掺量保持在一定范围内,在一定掺入方式下,沥青混凝土强度及路用特性均满足规范要求。加入抗剥落剂或使用改性沥青,废旧玻璃沥青混凝土的水稳定性明显提升。混合料疲劳寿命不易受废旧玻璃集料影响,在一定掺量及颗粒尺寸下,抗疲劳特性较好;蠕变特性与普通沥青混合料相似,在一定应力与温度范围内,蠕变变形小于普通沥青混合料,且可用常见流变模型来描述其永久变形特性。本文归纳总结了废旧玻璃材料作为沥青混合料集料的物理力学性能,废旧玻璃沥青混合料的材料组成设计方法,废旧玻璃对沥青混合料的路用性能和表面特性的影响规律,并展望了该领域未来的发展趋势。

The highway construction in China has been developing rapidly in recent years,as the highway mileage in 2016 reaches 131 000 kilometers,in which 95% are asphalt pavement.Asphalt pavement construction has consumed large amount of natural resources such as asphalt and natural stone,bringing a huge burden to environment.In order to decrease consumption of natural stone in road construction,research on the reuse of solid waste in asphalt concrete has been carried out worldwide.Waste glass is one of the common and continuously increasing solid wastes in daily life and industry,and seeking effective reutilization approach for waste glass is of great urgency.Thus the substitution of waste glass for partial natural stone in the production of asphalt concrete can be a potential scheme to solve both of the above thorny problems.It has been shown that crushed waste glass possesses properties such as wear resistance,slide resistance,light reflection and permeability,and can improve road performance of asphalt pavement effectively when substituting for partial natural aggregate to form surface layer concrete.However,the use of waste glass in asphalt concrete still faces several obstacles.As a brittle substance,waste glass mainly consists of hydrophilic SiO2,and will thereby affect strength and durability of asphalt concrete.Besides,most of waste glass originates from living garbage,and its gathering,sifting and crushing process is complicated and primitive in China.Hence the rigorous requirement for raw material＇s impurity content with road engineering elevates the technological threshold and cost for the reutilization of waste glass in asphalt pavement.These problems has prompted further investigations on engineering characteristics and composition of waste glass,and road performance and mechanical properties of asphalt concrete incorporating waste glass.And the strength and road performance of asphalt concrete with appropriate waste glass particle size content and mixing method can attain the standard requirement.The use of anti-stripping agent or modified asphalt can improve significantly moisture susceptibility of asphalt concrete incorporating waste glass.Fatigue life of the waste glass-contained mixture is scarcely affected by glass aggregate within a certain range of amount and particle size.Moreover,the creep characteristic of the admixture incorporating waste glass is similar to ordinary asphalt mixture,and creep deformation at high temperature is smaller than ordinary asphalt mixture and coincides with rheological model such as Burgers model.Based on the previous studies,this paper summarizes the physical and mechanical properties of waste glass serving as aggregate of asphalt admixture,the composition design methodology of asphalt mixture incorporating waste glass,as well as the influences of waste glass on engineering performance and surface features of the admixture as pavement surface layer.It also sketches out the future development trend.