摘要
自密实混凝土能否密实填充堆石孔隙不仅决定了堆石混凝土的强度,而且直接影响工程的质量和安全。自密实混凝土在堆石间隙中的流动可视为颗粒/Bingham流体两相流,其非牛顿流变特性和复杂通道使得流动格外复杂。本文采用格子Boltzmann方法和颗粒离散元耦合方法研究了自密实混凝土在堆石孔隙中的流动过程。发现自密实混凝土在堆石间隙中的流动状态分为稀疏流、密集流和堵塞三种状态,其中孔径比(出口尺寸与运动颗粒尺寸的比值)是影响自密实混凝土流动和堵塞的重要因素。自密实混凝土中颗粒的含量越高,流动越容易形成密集流和发生堵塞。对稳定的自密实混凝土密集流,建立了颗粒流量与孔径比的关系,可以应用这一关系完善自密实混凝土在堆石体中的浇筑技术和工艺。
Filling effect of self-compacting concrete（SCC） in rockfill gaps is a crucial factor of rockfilled concrete（RFC） strength and engineeing safety. The flow of fresh SCC in rockfill gaps can be regarded as a particle-Bingham fluid two-phase flow that is particularly complicated due to its nonNewtonian rheological characteristics and the complexity of its passage. In this work, SCC flows in the pores of rockfill material was studied by coupling the lattice Boltzmann method and particle discrete element method. We found out that these flows can fall into three regimes： dilute flow, dense flow and jamming. Aperture ratio, or the ratio of pore outlet size to particle diameter, is the most important factor of the flow and its jamming effect. It is much easier for SCC to form dense flow or jamming flow if its volume fraction of particles is higher. For dense flows, a relationship of outlet flow rate versus aperture ratio was established, which could be used to improve fresh concrete pouring technique.
作者
张传虎
金峰
陈松贵
徐小敏
ZHANG Chuanhu JIN Feng CHEN Songgui XU Xiaomin(State Key Laboratory of Hydroscience and Engineering, Tsinghua University, B eijing 100084 Tianjin Research Institute of Water Transport Engineering, Tianjin 300456 Department of Engineering, University of Cambridge, Cambridge, UK)
出处
《水力发电学报》
EI
CSCD
北大核心
2016年第10期112-120,共9页
Journal of Hydroelectric Engineering
基金
国家自然科学基金(51239006
51509139
11272048
11572178)
国家高技术研究发展计划(863)(2012AA06A112)
关键词
水工结构
堆石混凝土
自密实混凝土
数值模拟
两相流
堵塞规律
hydraulic structures
rock-filled concrete
self-compacting concrete
numerical simulation
two-phase flow
jamming law
