摘要
为探讨碾压荷载类型、颗粒级配及颗粒形状等对压实质量的影响,分析接触力场和速度场的变化规律,从细观上研究碾压混凝土颗粒在碾压过程中的运动规律、密度形成机制及压实特性,基于颗粒流软件(PFC3D),采用离散元法对碾压混凝土的碾压全过程进行数值仿真。结果表明,碾压过程中,细颗粒不断向粗颗粒附近聚集;振动碾压阶段对碾压混凝土的孔隙率影响最大;在总孔隙率相对较低的条件下改变级配,中等骨料的含量对碾压混凝土的压实孔隙率有显著影响;骨料中球形颗粒较扁平、细长颗粒多时,碾压混凝土更易被压实。
To investigate the influence of rolling load type, grain size distribution and particle shape on the compaction performance of roller compacted concrete （RCC）, by analyzing the contact stress field and velocity fieid of particles, the RCC particles＇ moving law, compacted mechanism and compaction properties under compacting loads were visually re- searched from the micro perspective. Based on the particle flow code （PFC3D）, the whole compacted process of RCC was numerically simulated by using the discrete element method （DEM）. The results show that the fine particles continuously move to the coarse particles once the compacting loads are applied. Compared with static loads, vibrating compaction stage has more significant impact on RCC^s porosity. Changing the grain size distribution with relatively low porosity, medium particles can heavily influence the compaction quality of RCC. When compared to the flat and slender particles, aggregate of spherical particles can be compacted more easily.
出处
《水电能源科学》
北大核心
2015年第6期88-92,104,共6页
Water Resources and Power
基金
国家重点基础研究发展计划(973计划)项目(2013CB035901)
关键词
碾压混凝土
碾压特性
离散元
数值模拟
细观机制
roller compacted concrete
compaction properties
discrete element method
numerical simulation
micro mechanism
