考虑配筋影响的混凝土导热性分析  

Reinforcement influence-considered analysis on thermal conductivity of concrete

作　　者：徐晓蔚 杜彬 童富果[1] 查新元 XU Xiaowei;DU Bin;TONG Fuguo;ZHA Xinyuan(College of Hydraulic&Environmental Engineering,China Three Gorges University,Yichang443000,Hubei,China;Yichang Tianyu Science&Technology Limited Company,Yichang443002,Hubei,China)

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443000 [2]宜昌天宇科技有限公司,湖北宜昌443002

出　　处：《水利水电技术（中英文）》2021年第5期185-195,共11页Water Resources and Hydropower Engineering

基　　金：国家重点研发计划(2017YFC1501100);国家自然科学基金项目(51279090,51679129)。

摘　　要：为了定性、定量研究钢筋对混凝土结构整体导热性的影响,采用复合形法并结合有限元数值模拟分析了配筋率及钢筋布设方式对混凝土导热性的影响规律,进而基于Weiner-bound模型,引入参数μ1、μ2作为表征上下限数值对钢筋混凝土有效导热系数的权重,发展了一种考虑不同方向配筋率影响的混凝土导热系数模型。研究表明:钢筋混凝土的导热性随着配筋率的增大而增大,钢筋的布设方式对混凝土导热性的影响同样明显。当竖向钢筋的配筋率从0%增长到8.038 4%时,竖向导热系数λz最大增幅为64.52%,而平面正交方向的导热系数增幅仅为15.34%,这说明在相同配筋率的条件下,平行于热流传导主向布置的钢筋对于结构整体的导热性提升较大,而垂直于热流传导主向布置的钢筋对于结构导热性提升相对较小。不同方向布置的钢筋对于导热张量主元的影响程度不一,使得钢筋混凝土的导热性呈现出各向异性。将钢筋混凝土模型实测数据与模型预测值相对比,两者数据偏差基本在±10%以内,模型适应性强,可用于考虑不同方向配筋率的钢筋混凝土导热系数预测。In order to qualitatively and quantitatively study the influence of reinforcement on the overall thermal conductivity of concrete structure, the laws of the influences from both the reinforcement ratio and the reinforcement layout on concrete thermal conductivity are analyzed with the complex method combined with finite element numerical simulation, and then the parameters μ1 and μ2 are introduced to characterize the weights of both the upper and the lower limit values on the effective thermal conductivity of reinforced concrete on the basis of Weiner bound model, thus a concrete thermal conductivity model considering the influences of reinforcement ratio in different directions is developed. The study results show that the thermal conductivity of reinforced concrete increases along with the increase of reinforcement ratio, while the influence from the layout of reinforcement on the thermal conductivity of concrete is also obvious. When the reinforcement ratio of vertical reinforcement increases from 0% to 8.038 4%, the maximum increasing amplitude of vertical thermal conductivity λZ is 64.52%, while that in the plane orthogonal direction is only 15.34%, which indicates that under the condition of the same reinforcement ratio, the enhancement of the thermal conductivity of the overall structure from the reinforcement arranged parallelly to the main direction of heat flow conduction is larger, while the enhancement of the structural thermal conductivity from the reinforcement arranged perpendicularily to the main direction of heat flow conduction is less. The influences from the reinforcements arranged in different directions on the principal component of thermal conductivity tensor are different, which makes the thermal conductivity of reinforced concrete exhibit anisotropy. Comparing the relevant measured data obtained from the reinforced concrete model with the predicted values of the model, the data deviation between them are basically within ±10%, thus can be used to predict the thermal conductivity of th

关 键 词：导热性 钢筋混凝土 正交各向异性 复合形法 有限元分析 混凝土 温度应力 数值模拟 

分 类 号：TU375.6[建筑科学—结构工程]