摘要
微波照射回收废弃混凝土中的粗骨料是一种高效、节能、环保的混凝土再资源化技术。粗骨料表面附着砂浆耗散的微波能量对于回收粗骨料的质量有显著影响。本实验选取了两种常见的粗骨料,花岗岩和玄武岩,制成表面包裹均匀厚度砂浆的试样进行微波加热试验,研究了不同的砂浆厚度和含水率下试样表面的温度变化,并对微波照射后砂浆失水特性、裂纹扩展及破坏特征进行了分析。微波加热结束后剔除粗骨料表面剩余的附着砂浆,选取形状完整未发生熔融的粗骨料进行单轴抗压强度测试,研究包裹砂浆对微波照射粗骨料强度折减的影响。结果表明:微波照射后花岗岩和玄武岩骨料的强度随粘结砂浆含水量的增加而增加;微波照射后花岗岩骨料强度随黏附砂浆厚度增加而增加,玄武岩骨料强度随黏附砂浆厚度增加呈下降趋势。与厚度相比,砂浆的含水率对微波加热后粗骨料的强度影响更大。
Microwave irradiating waste concrete to recover coarse aggregates is an efficient,energysaving and environmental technique for concrete recycling.Microwave energy dissipated by adhering mortar of coarse aggregates has a strong impact on the quality of recycled coarse aggregates.Two common coarse aggregates,granite and basalt,were selected to make samples consisting of coarse aggregate uniformly surrounded by mortar for microwave heating experiments.Temperature changes of the sample surface under different mortar thickness and water content were studied,and the water loss characteristics,crack growth and failure characteristics of the mortar after microwave irradiation were analyzed.The remaining adhering mortar of coarse aggregate was removed after microwave heating.The unmelted coarse aggregates with intact shape were selected for uniaxial compressive strength test to study the effects of surrounding mortar on strength reduction of the coarse aggregate under microwave irradiation.The obtained results show that:the strength of granite and basalt aggregates after microwave irradiation increase with the moisture content of adhering mortar.The strength of granite aggregates after microwave irradiation increase with the thickness of the adhering mortar,while the strength of basalt aggregates shows a downtrend with the increasing thickness of the adhering mortar.Comparing with the thickness,the moisture content of mortar has a greater influence on the strength of the coarse aggregate after microwave heating.
作者
邵珠山
王维涛
赵冬
袁媛
郭轩
SHAO Zhushan;WANG Weitao;ZHAO Dong;YUAN Yuan;GUO Xuan(School of Science,Xi’an University of Architecture and Technology,Xi’an 710055,China;Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering,Xi’an 710055,China)
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2024年第1期27-34,共8页
Journal of Materials Science and Engineering
基金
国家自然科学基金资助项目(11872287)
陕西省重点研发计划资助项目(2019ZDLGY01-10)
陕西省自然科学基础研究计划资助项目(2023-JC-QN-0451)
中国博士后科学基金资助项目(2022M712495)。
关键词
混凝土
微波加热
砂浆厚度
含水率
强度弱化
Concrete
Microwave heating
Mortar thickness
Moisture content
Strength weakening
