| 摘要: |
| 为了研究水泥基材料溶液传输过程中水分与离子的耦合作用,首先采用自生长模型,考虑水灰比、水化度对孔隙率的影响,建立了水泥基多孔介质的细观结构模型.然后,采用格子玻尔兹曼方法,分别模拟了水分传输、离子扩散和溶液传输,再现了气液两相的转化与传输现象.结果表明：孔隙率越大,传输速率越快;饱和多孔介质中,离子在水中沿孔隙扩散;由于对流作用的存在,干燥多孔介质中溶液主导的离子传输速率快于饱和多孔介质中的速率.该工作揭示了水泥基材料中溶液传输过程的细观机理,为深入理解混凝土耐久性的真实发生过程奠定了基础. |
| 关键词: 水泥微观模型 离子扩散 水分传输 格子玻尔兹曼方法 |
| DOI：103969/j.issn.1007 9629202104007 |
| 分类号: |
| 基金项目:国防科技创新特区“珊瑚骨料混凝土”项目;国家自然科学基金资助项目(51308334);“十三五”国家重点研发计划项目（2016YFC0701003） |
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| Numerical Simulation of Solution Transportation in Cementitious Materials Based on Lattice Boltzmann Method |
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LI Dongyao1, SHAN Yuhan1, HAN Yudong2, DING Xiaoping2, HOU Dongwei1
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1.Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;2.Central Research Institute of Building and Construction, MCC Group Co., Ltd., Beijing 100088, China
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| Abstract: |
| In order to study the coupling effect of water and ions in the process of solution transportation in cementitious materials, the self growth model was proposed first. Considering the influence of water cement ratio and hydration degree on porosity, a meso structure model of cement based porous media was established. Then, using the lattice Boltzmann method, the water transportation, ion diffusion, and solution transportation were simulated respectively, and the transformation and transportation of gas liquid two phase phenomena were simulated. The results show that the greater the porosity, the faster the transmission rate. In saturated porous media, ions diffuse along the pores in the water; while in dry porous media, the ion transmission rate dominated by solution is faster than that in saturated porous media due to the existence of convection. This work reveals the meso mechanism of the solution transfer process in cement based materials, and lays the foundation for a deep understanding of the actual occurrence of concrete durability. |
| Key words: mesoscopic cement model ion diffusion water transportation lattice Boltzmann method |
