微波和传统加热下混凝土劈裂抗拉性能分析  

ANALYSIS OF SPLITTING TENSILE PROPERTIES OF CONCRETE UNDER MICROWAVE AND CONVENTIONAL HEATING CONDITIONS

作　　者：魏玮 张宏亮[3] 邵珠山 江岩松 WEI Wei;ZHANG Hong-liang;SHAO Zhu-shan;JIANG Yan-song(School of Science,Xi’an University of Architecture and Technology,Xi’an,Shaanxi 710055,China;Post-Doctoral Research Center,School of Architecture,Xi’an University of Architecture and Technology,Xi’an,Shaanxi 710055,China;School of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an,Shaanxi 710055,China)

机构地区：[1]西安建筑科技大学理学院,陕西西安710055 [2]西安建筑科技大学建筑学院博士后研究中心,陕西西安710055 [3]西安建筑科技大学土木工程学院,陕西西安710055

出　　处：《工程力学》2024年第5期134-145,共12页Engineering Mechanics

基　　金：国家自然科学基金面上项目(11872287);国家自然科学基金青年项目(12202333);中国博士后科学基金70批面上资助项目(2021MD703868)。

摘　　要：近年来,微波辅助混凝土粗骨料回收技术因其绿色性、高效性及低损伤性引起国内外学者广泛关注。该文采用工业微波多模谐振腔及传统马弗炉对圆柱体混凝土试样进行不同条件下的加热实验,探讨了混凝土在两种加热方式下的加热效率、宏观裂纹扩展与破坏模式、劈裂抗拉强度弱化规律以及加热参数对能耗和能效的影响规律。此外,借助扫描电镜分析了微波照射下混凝土的抗拉强度弱化机理。实验结果表明:微波加热技术具有更高的加热效率,能够有效地促使裂纹沿砂浆-骨料界面扩展,从而削弱混凝土强度;并且高微波功率下混凝土加热效率更高,强度损失更大,能量消耗更少。反之,传统加热下砂浆-骨料界面结构紧凑,未出现可见裂纹,加热过程能量利用率仅1%左右。Microwave-assisted concrete coarse aggregate recycling technology has attracted extensive attention from scholars at home and abroad due to its green,effective,and low aggregate damage recycling properties.A multi-mode microwave resonator and conventional muffle furnace were employed to heat the cylindrical concrete specimens with different energy inputs.The investigation was performed for the heating efficiency,macroscopic crack expansion,material failure mode,splitting tensile strength weakening laws,and the influence laws of heating parameters on energy consumption and on energy efficiency.In addition,the mechanism of tensile strength weakening of concrete under microwave irradiation was analyzed through the scanning electron microscopy(SEM)tests.The experimental results show that the microwave heating technology has higher heating efficiency and can effectively promote crack propagation along the mortar-aggregate interface and then weaken the concrete strength.The higher the microwave power,the higher the thermal efficiency of concrete,the greater strength loss of concrete,and the lower the energy consumption.However,the mortar-aggregate interface was still compact under conventional heating,with no visible cracks occurred,and the energy efficiency during heating process was only about 1%.

关 键 词：混凝土 微波加热 传统加热 巴西劈裂实验 强度弱化 能量消耗 

分 类 号：TU528[建筑科学—建筑技术科学]