| 摘要: |
| 采用COMSOL与MATLAB联合仿真的方法，基于混凝土二维细观几何模型，实现了混凝土稳态热传导的数值模拟.在利用试验结果验证数值模拟有效性的基础上，分析了骨料随机分布对混凝土导热性能的影响，并讨论了粗骨料粒径、形状及其体积分数，以及分散相导热系数对混凝土导热性能的影响规律.结果表明：粗骨料随机分布是造成混凝土导热性能产生随机性的重要因素；混凝土导热系数相对平均值随着粗骨料体积分数、分散相导热系数的增加而增大，但受粗骨料粒径和形状的影响不大；粗骨料体积分数越高，分散相与水泥砂浆导热系数相差越大，粗骨料粒径越大，轴长比越大，混凝土导热系数的变异性越显著，但当粗骨料体积分数超过35%后混凝土导热系数的变异性基本保持不变. |
| 关键词: 混凝土 导热性能 数值分析 粗骨料分布 |
| DOI：103969/j.issn1007 9629201702002 |
| 分类号: |
| 基金项目:国家重点基础研究发展计划(973计划)项目(2015CB655103) |
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| Effects of Randomly Distributed Aggregates on Thermal Properties of Concrete |
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ZHANG Weiping, WANG Hao, GU Xianglin
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Department of Structral Engineering, Tongji University, Shanghai 200092, China
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| Abstract: |
| Based on the meso scale model of concrete, a simulation method combining COMSOL with MATLAB was used to inverse heat conduction problems of concrete in steady state. With the verified simulation method, effects of randomly distributed aggregates on thermal conductivity of concrete were analyzed, and influence of aggregate content, aggregate gradation, aggregate shape and thermal conductivity of the dispersed phase were also discussed. It has been shown that coarse aggregate distribution is an important factor causing randomness of thermal conductivity of concrete. The average thermal conductivity of concrete increases with the increased volume content and thermal conductivity of aggregate, while aggregate size and particle shape have little impact on the average thermal conductivity of concrete. Thermal conductivity increases with the increasing aggregate volume content, but remains unchanged if aggregate volume content exceeds 35%. It is also found that the thermal conductivity of concrete changes more significantly with the increase of proportion of large particle aggregates, the axial length of aggregates and the difference of thermal conductivity between dispersed phase and cement mortar. |
| Key words: concrete thermal property numerical analysis coarse aggregate distribution |
