基于多相复合材料的混凝土导热系数预测模型

发布时间：2018-03-22 02:01

本文选题：混凝土　切入点：复合材料　出处：《水利学报》2017年07期 　论文类型：期刊论文

【摘要】：混凝土温度场分析是混凝土结构耐久性以及服役寿命预测的重要依据,而导热系数则是确定时变温度场分布的主要参数。考虑材料组成的非均质性,将混凝土视为由连续相水泥砂浆、分散相粗骨料以及二者薄弱界面过渡区(ITZ)组成的三相复合材料,并基于复合材料导热系数模型,建立了混凝土及其组成单元(水泥砂浆和ITZ界面)导热系数的计算模型;在此基础上,对比分析了水灰比、粗骨料体积分数、砂率、饱和度和界面热阻等因素对混凝土导热系数的影响规律。结果表明:混凝土导热系数随饱和度、粗骨料体积分数的增加而增大,随水灰比的增大而减小;考虑界面热阻的混凝土导热系数预测模型,能够更好地揭示饱和度与砂率对混凝土导热系数的影响机理。
[Abstract]:The concrete temperature field analysis is an important basis for the prediction of concrete structure durability and service life, and is the main parameters of variable thermal conductivity temperature field distribution determined. Considering the heterogeneity of material composition, the concrete is considered as a continuous phase of cement mortar, the dispersed phase of coarse aggregate and two weak interfacial transition zone (ITZ) three phase the composition of the composite material, and the thermal conductivity of composite materials based on the model, a concrete and unit (cement mortar and ITZ interface) calculation model of thermal conductivity; on the basis of comparative analysis of the water cement ratio, the volume fraction of coarse aggregate, sand ratio, influence factors of saturation and the interfacial thermal resistance of concrete thermal conductivity. The results show that the thermal conductivity of concrete with saturation, increase the coarse aggregate volume fraction increases with the increase of water cement ratio decreases; considering the thermal conductivity of concrete interfacial thermal resistance The prediction model can better reveal the influence mechanism of saturation and sand ratio on the thermal conductivity of concrete.

【作者单位】：大连理工大学海岸和近海工程国家重点实验室;
【基金】：国家自然科学基金面上项目(51378090) 国家重点基础研究发展计划项目(2015CB057703) 高性能土木工程材料国家重点实验室开放基金项目(2016CEM007)
【分类号】：TU528

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