摘要
使用回收的建筑拆除废弃物作为无黏结骨料是路面基层/底基层施工的资源节约型、经济型和生态友好型替代方法之一。单个粗集料颗粒的细观强度和压碎特性会对此类再生无黏结集料的宏观强度和变形行为产生重大影响。本文通过单颗粒压碎试验和侧限压缩试验系统地研究了不同粒径和成分的再生骨料的压碎强度和压缩变形特性。试验结果表明,单颗粒破碎强度具有显著的尺寸效应,对于同种类型的再生骨料,破碎应力峰值随颗粒尺寸的增大而减小。此外,采用双曲线函数可以很好地描述侧限压缩过程的应力-应变关系。在相同的垂直应力水平下,随着粒径的增大,垂直应变和屈服应力值分别逐渐增大和减小。最后,采用颗粒破碎指标B_(r)量化了不同垂直应力水平下各粒度范围的颗粒破碎情况。根据破碎指标Br的预测公式的极限值,可得出各粒度范围的极限破碎状态。
The use of recycled building demolition wastes(BDWs)as unbound aggregate materials(UAMs)is one of the resource-conserving,economical,and eco-friendly alternatives for pavement base/subbase construction.The mesoscale strength and crushing properties of individual coarse aggregate particles significantly affect macroscopic strength and deformation behavior of such recycled UAMs.In this paper,the crushing strength and compressive deformation of recycled BDW aggregates of different sizes and constituents were systematically studied from single particle crush tests and oedometer tests,respectively.The test results demonstrate that the single-particle crushing strength exhibited significant size effect and the peak crushing stress values decreased with increasing particle size for the same constituent type of recycled BDW particles.The stress−strain relationship obtained from oedometer tests was well described by the hyperbolic function.Under the same vertical stress level,the vertical strain and the yield stress values of the oedometer specimens increased and decreased gradually with increasing particle size,respectively.Finally,the relative breakage index B_(r)was used to quantify particle breakage for each particle size range under different vertical stress levels.The ultimate crushing state of each particle size range was obtained from the limit of each predictive equation of the relative breakage index Br.
作者
孔坤锋
陈锋
肖源杰
李昀博
姜钰
王萌
TUTUMLUER Erol
陈宇亮
李志勇
KONG Kun-feng;CHEN Feng;XIAO Yuan-jie;LI Yun-bo;JIANG Yu;WANG Meng;TUTUMLUER Erol;CHEN Yu-liang;LI Zhi-yong(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;School of Civil Engineering,Central South University,Changsha 410075,China;Key Laboratory of Engineering Structures of Heavy-haul Railway of Ministry of Education(Central South University),Changsha 410075,China;Department of Civil&Environmental Engineering,University of Illinois at Urbana-Champaign,Urbana,IL 61801,U.S.A.;Hunan Communications Research Institute Corporation Limited,Changsha 410015,China)
基金
Project(52178443)supported by the National Natural Science Foundation of China
Project(2019YFC1904704)supported by the National Key R&D Program of China
Project(2022YJ120)supported by the Key R&D Program of Chinese Academy of Railway Sciences
Projects(2022JZZ03,2021JZZ01,2021JZZ02)supported by the Open Foundation of Key Laboratory of Engineering Structures of Heavy Haul Railway of Ministry of Education,China。
关键词
建筑拆除废弃物
再生骨料
颗粒破碎
永久变形
单颗粒破碎试验
侧限压缩试验
building demolition waste
recycled aggregates
particle breakage
permanent deformation
single-particle crushing test
oedometer test
