摘要
温度场是影响混凝土结构耐久性评价的重要因素之一,密度、质量热容、导热系数是混凝土材料的主要热学参数,决定于混凝土组成及细观结构。基于混凝土二维三相细观几何模型,考虑各相材料热学参数温度依赖性,得到了混凝土宏观热学参数并与试验结果比较。在验证该数值方法有效性的基础上,开展了升温过程中界面层厚度、界面层材料属性对混凝土热学参数的影响规律及影响程度分析。研究表明:随着温度升高,混凝土密度、导热系数逐渐降低,混凝土质量热容逐渐升高;随着界面层厚度增加,混凝土密度、导热系数逐渐减小,混凝土质量热容略微增大;界面层厚度的变化对混凝土导热系数影响最大,密度次之,对质量热容影响不显著;随着界面层导热系数、密度、质量热容的增加,混凝土的热学参数随之增加,但增幅有差异。
Temperature field is one of the important factors affecting the durability evaluation of concrete structures.Density,specific heat capacity and thermal conductivity are the main thermal parameters of concrete materials,which are determined by concrete composition and mesostructure.Based on the two-dimensional three-dimensional mesoscopic geometry model of concrete,considering the temperature dependence of thermal parameters of each phase material,the macroscopic thermal parameters of the concrete are obtained and compared with the experimental results.On the basis of verifying the validity of the numerical method,the influence of the thickness of the interface layer and the material properties of the interface layer on the thermal parameters of the concrete and the degree of influence were analyzed.Studies have shown that as the temperature increase,the concrete density and thermal conductivity decrease gradually,and the concrete specific heat capacity gradually increase.As the thickness of the interface layer increases,the concrete density and thermal conductivity decrease gradually,and the concrete specific heat capacity increase.The change of interface layer thickness has the greatest influence on the thermal conductivity of concrete,followed by density,and the effect of comparative heat capacity is not significant.As the thermal conductivity,density,and specific heat capacity of the interface layer increase,the thermal parameters of the concrete increase,but the increase is different.
作者
王彦丹
李宗利
WANG Yandan;LI Zongli(College of Water Resources&Architectural Engineering,Northwest A&F University,Xianyang 712100,China)
出处
《混凝土》
CAS
北大核心
2021年第2期37-41,共5页
Concrete
基金
“十三五”国家重点研发计划资助项目(2017YFC405101-2)
国家自然科学基金资助项目(51379178)。
关键词
混凝土
热学参数
温度效应
界面层
细观模型
concrete
thermal parameters
temperature effect
interface layer
mesoscopic model
