基于性能的级配碎石混合料设计指标  

Performance-based Design Indicators for Graded Macadam Mixture

作　　者：涂慕溪 严二虎[2] 陈礼彪[1] 曾俊铖[1] 肖光书 TU Mu-xi;YAN Er-hu;CHEN Li-biao;ZENG Jun-cheng;XIAO Guang-shu(Expressway Construction Headquarters of Fujian Province,Fuzhou Fujian 350001,China;Research Institute of Highway,Ministry of Transport,Beijing 100088,China;Fujian Road and Bridge Construction Co. ,Ltd. ,Fuzhou Fujian 350002,China)

机构地区：[1]福建省高速公路建设总指挥部,福建福州350001 [2]交通运输部公路科学研究院,北京100088 [3]福建路桥建设有限公司,福建福州350002

出　　处：《公路交通科技》2019年第9期31-36,共6页Journal of Highway and Transportation Research and Development

摘　　要：为提高高速公路用级配碎石基层的混合料质量,需要建立基于性能的级配碎石混合料设计指标。利用BISAR程序计算了福建典型结构级配碎石的最大应力、最大剪应力值,同时预估了100 kN标准荷载作用2 000万次下级配碎石变形量占结构总变形量的百分比;然后选择12种级配碎石混合料测定了动态三轴试验的回弹模量、变形率和静态三轴试验的剪切强度;最后分析提出了基于性能的级配碎石混合料设计指标,用于指导福建省级配碎石混合料设计。结果表明:⑴级配碎石需要足够的模量来保证承载能力,同时在沥青路面结构中该混合料可能会产生压缩永久变形或剪切破坏,因此其混合料需要具有一定的抗永久变形能力和较高的剪切强度;(2)可以取回弹模量300 MPa作为级配碎石混合料承载能力的性能指标;(3)福建省典型结构中级配碎石基层最大剪应力为332.8 kPa,最大主应力为396 kPa,考虑1.2倍保证系数,可以取静态三轴试验的剪切强度395 kPa作为级配碎石混合料的抗剪设计指标;(4)按照级配碎石基层永久变形量占结构总变形率不大于13%考虑,可以取动态三轴试验的20 000次和50 000次的变形率不大于10-8作为级配碎石混合料抗永久变形设计指标。In order to improve the quality of the mixture used for graded macadam base of expressway, it is necessary to establish the performance-based design indicators for graded macadam mixture. The maximum stress and maximum shear stress of the graded macadam in typical structure of expressways in Fujian Province are calculated by using BISAR program, and the proportion of deformation of the graded macadam under 20 million times of 100 kN standard load to the total deformation structure is forecasted. Then, selecting 12 kinds of graded macadam mixture, the resilient moduli, deformation rates are measured by dynamic triaxial test, and the shear strengths are measured by static triaxial test. Finally, the performance-based design indicators for graded macadam mixture are analysed and proposed to guide the design of graded macadam mixture in Fujian Province. The result shows that(1) the graded macadam needs sufficient modulus to ensure the bearing capacity, and the mixture in asphalt pavement structure may produce permanent compressive deformation or shear failure, therefore, the mixture should have good resistance to permanent deformation and higher shear strength;(2) the resilient modulus of 300 MPa can be used as the permanent indicator of bearing capacity of the graded macadam mixture;(3)the maximum shear stress and the maximum main stress of the graded macadam base of typical structure in Fujian Province are 332.8 kPa and 396 kPa respectively, and the shear strength of 395 kPa obtained by static triaxial test can be used as the indicator of resisting shear of the graded macadam mixture considering 1.2 times of guarantee coefficient;(4) considering that the permanent deformation of the graded macadam base in typical structure is no more than 13% of the total deformation of the structure, the deformation rate of no more than 10-8 in the 20 000 th and 50 000 th cycles of dynamic triaxial test can be used as the indicator of resistance to permanent deformation of the graded macadam mixture.

关 键 词：道路工程 级配碎石 动态三轴试验 永久变形率 剪切强度 

分 类 号：U416[交通运输工程—道路与铁道工程]