摘要
20世纪60年代初,加拿大日益增长的交通量促使交通部门逐渐使用硬度较高的沥青来防止沥青路面轮迹带出现早期车辙。由于硬质沥青的内部低温温度应力较高,低温抗裂韧性较差,因此采用硬质沥青的路面表面通常会出现等间隔分布的横向裂缝。围绕低温裂缝的沥青路面试验段研究证实了沥青的一致性、温度敏感性、相态均匀性和耐久性的重要影响。为了解决改性沥青的使用对现有沥青性能评价体系带来的挑战,20世纪90年代,加拿大沥青路面试验段集中研究和评估了美国的Superpave^(TM)规范的可靠性,结果表明:吹制沥青的耐久性较差,聚合物改性剂只对软沥青的耐久性存在提升作用。21世纪初期,在安大略省政府的委托下,沥青路面试验段研究主要考虑了沥青的相分离、相转变和热可逆老化(凝胶化)等现象,以及聚合物和纤维对沥青耐久性的影响,进而对现有沥青性能测试规范进行改进。研究发现,对于相同的Superpave分级的不同胶体类型(溶胶,凝胶,溶凝胶)的沥青,相应沥青路面的收益/成本比最大可相差2~3倍。可通过合理评估和选择沥青的类型来延长沥青路面的使用寿命,比如阿尔伯塔油砂沥青(溶胶型),相比于高掺量的聚合物改性沥青、氧化程度较高的再生沥青或含蜡量较高的沥青(凝胶型),其蜡含量较低,只需要配合少量的聚合物或纤维改性即可显著提升沥青路面的使用寿命。改进的沥青胶结料测试规范有助于节约成本,有效应对全球气候变化下2500万km的沥青路面养护维护需求。在总结加拿大过去60年沥青路面现场试验段研究的基础上,该文对未来的寒区道路研究内容和关键技术问题提出了新的展望和建议,可为未来的研究提供参考。
During the early 1960s,Canadian road authorities began using stiffer asphalt to address the issue of early rutting in the wheel track zone of asphalt pavements,which was caused by the growing traffic volumes.Pavements constructed with stiffer asphalt commonly exhibit evenly spaced transverse cracks due to the significant internal stresses caused by low temperatures and the inadequate resistance of the asphalt to cracking under such conditions.Research conducted on asphalt pavements with cracks caused by low temperatures has verified the significant impact of asphalt’s consistency,temperature sensitivity,phase uniformity,and durability.In order to tackle the difficulties presented by the utilization of modified asphalt in the current asphalt performance evaluation system,the Canadian asphalt pavement test section during the 1990s was used to examine and assess the dependability of the U.S.Superpave^(TM)specification.The results reveal that blown asphalt exhibits inadequate durability,while polymer modifiers only improve the durability of soft asphalt.In the early 21st century,the Ontario municipality commissioned studies on asphalt pavement test sections to enhance the current asphalt performance test specifications.These studies mainly considered the occurrences of phase separation,phase transformation,and thermally reversible aging(gelation)of asphalt,as well as the impact of polymers and fibers on the durability of asphalt.The results find that using different types of colloids(sol,gel,and sol-gel)in the same Superpave level can result in asphalt pavements with benefit/cost ratios varying by up to 2-3 times.By assessing and choosing the appropriate type of asphalt,such as Alberta oil sand asphalt(sol),the service life of asphalt pavements can be prolonged.Compared with polymer-modified asphalt with high content,more oxidized recycled asphalt,or asphalt with higher wax content(gel),Alberta oil sand asphalt has lower wax content.The service life of asphalt pavements can be further improved by incorporating smal
作者
王迪
李京效
任学元
张帆
袁东东
WANG Di;LI Jingxiao;REN Xueyuan;ZHANG Fan;YUAN Dongdong(University of Ottawa,Ottawa,ON K1N 6N5,Canada;School of Highways,Chang’an University,Xi’an,Shaanxi 710064,China;Aalto University,Espoo,02150,Finland)
出处
《中外公路》
2024年第5期284-300,共17页
Journal of China & Foreign Highway
基金
重庆交通大学交通土建工程材料国家地方联合工程研究中心开放基金项目(编号:TCEM-2023-02)。
关键词
路面试验段
沥青规范
流变类型
生命周期成本分析
长寿命路面
pavement test section
asphalt specification
rheological types
life-cycle cost analysis
long-life pavement
