再生混凝土热传导细观数值模拟  

Mesoscopic numerical simulation of heat conduction in recycled concrete

作　　者：王宇航 金立兵[1] 吴强 薛鹏飞[1] 张业盛 WANG Yu-hang;JIN Li-bing;WU Qiang;XUE Peng-fei;ZHANG Ye-sheng(School of Civil Engineering,Henan University of Technology,Zhengzhou 450001,China;Design&Research Institute of Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学土木工程学院,河南郑州450001 [2]河南工大设计研究院,河南郑州450001

出　　处：《河南城建学院学报》2023年第5期14-21,共8页Journal of Henan University of Urban Construction

基　　金：河南省重点研发与推广专项(212102110191,212102110200,232102320014);河南工业大学自科创新基金(2022ZKCJ06)。

摘　　要：再生混凝土相比于普通混凝土孔隙率大、吸水率高、密度较低,在热工性能方面具有较大的优势。通过自编程序,对有限元软件进行二次开发,建立了再生混凝土稳态热传导数值模型。数值模拟结果与试验结果吻合度较好。对影响再生混凝土热导率的因素进行数值分析,从细观层次上揭示了再生混凝土热工性能的影响机理。结果表明:当再生粗骨料体积分数由0%增加到50%时,再生混凝土的热导率增加了50.2%,说明再生粗骨料可以促进再生混凝土内部热量的传输,显著影响再生混凝土热导率;在再生粗骨料体积一定时,五相热导率对再生混凝土热导率的影响程度从高到低依次为新硬化砂浆、天然粗骨料、旧附着砂浆、新界面过渡层、旧界面过渡层;当界面过渡层厚度增加时,再生混凝土热导率降低。界面过渡层类似于“热阻器”,能够减缓热量的耗散,提高再生混凝土的保温隔热效果。Compared with ordinary concrete,recycled concrete has larger porosity,higher water absorption and lower density,and has greater advantages in thermal performance.Through self-programming and secondary development of finite element software,a numerical model of steady-state heat conduction of recycled concrete was established.The numerical simulation results are in good agreement with the experimental results.Numerical analysis of the factors affecting the thermal conductivity of recycled concrete reveals the influencing mechanism of the thermal performance of recycled concrete from a microscopic level.The results show that when the volume fraction of recycled coarse aggregate increases from 0%to 50%,the thermal conductivity of recycled concrete increases by 50.2%,indicating that recycled coarse aggregate can promote the internal heat transmission of recycled concrete and significantly affect the thermal conductivity of recycled concrete;when the volume of recycled coarse aggregate is constant,the influence degree of five-phase thermal conductivity on the thermal conductivity of recycled concrete from high to low is newly hardened mortar,natural coarse aggregate,old attached mortar,new interface transition layer,and old interface transition layer;when the thickness of the interface transition layer increases,the thermal conductivity of recycled concrete decreases.The interface transition layer is similar to a"thermal resistor",which can slow down the dissipation of heat and improve the thermal insulation effect of recycled concrete.

关 键 词：再生混凝土 热传导 五相模型 热导率 数值模拟 

分 类 号：TU528[建筑科学—建筑技术科学]