RAP chunks produced in cold milling operation of asphalt pavement:Evaluation,mechanism,and engineering investigation in China  

作　　者：Yuquan Yao Jiangang Yang Jie Gao Mulian Zheng Liang Song Jing Xu Chen Sun 

机构地区：[1]Key Laboratory for Special Area Highway Engineering of Ministry of Education,Chang'an University,Xi'an 710064,China [2]Department of Engineering and Architecture,University of Parma,Parma 43124,Italy [3]School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,China [4]School of Traffic and Transportation Engineering,Xinjiang University,Urumqi 830049,China [5]Xinjiang Communications Investment Group Construction Management Co.,Ltd,Urumqi 830099,China [6]Jiangxi Tianchi Expressway Technology Development Co.,Ltd,Nanchang 330100,China

出　　处：《Journal of Traffic and Transportation Engineering(English Edition)》2024年第5期972-1000,共29页交通运输工程学报（英文版）

基　　金：found by the National Natural Science Foundation of China(grant number 52268068,52368062,52368064);the Natural Science Foundation of Jiangxi Province(grant number 20232BAB214076,20232BAB204085);the National High-level University Scholarship Program(grant number 202306560084);the Fundamental Research Funds for the Central Universities,CHD(grant number 300102210501);the Tianshan Leading Talents in Scientific and Technological Innovation(grant number 2022TSYCLJ0045);the Science and Technology Projects of Xinjiang Communications Investment Group Co.,Ltd(grant number ZKXFWCG-202211-010).

摘　　要：Cold milling is a widely used method for rehabilitating asphalt pavement,generating reclaimed asphalt pavement(RAP)chunks.Within this process,aggregates within the asphalt pavement will be crushed,forming RAP agglomerates and aggregate breakdown.However,the mechanism of these phenomena has remained unclear,and a unified evaluation method has yet to be established.In this study,RAP agglomeration and aggregate fragmentation were characterized,five distinct methods were systematically assessed,and the mechanism of RAP agglomeration and breakdown was analyzed by discrete element method(DEM)simulation based on setting different particle contact parameters,then followed by a mechanical analysis,and demonstrated in engineering.The results revealed that both agglomeration and aggregate breakdown occur within RAP particles of various sizes,with the five methods showing similar trends in quantifying these effects.Through DEM simulations and mechanical analyses,the aggregate breakdown predominantly occurs at the cutter's motion trajectory of the cutter and during crack propagation,while agglomeration was mainly related to the sliding surface's area.The milling speed and depth positively impact RAP agglomeration,while negatively affecting aggregate breakdown,and milling drum speed exerts minimal influence on these phenomena.RAP agglomeration varies considerably in different engineering projects,and cold milling parameters should be determined based on the material composition of the asphalt pavement and design requirements to control agglomeration and breakdown rates of RAP.

关 键 词：Reclaimed asphalt pavement Cold milling operation RAP agglomeration Aggregate breakdown Discrete element method 

分 类 号：U416.217[交通运输工程—道路与铁道工程] U418.6