再生粗骨料对不同强度等级混凝土性能的影响  

Effects of Recycled Coarse Aggregate on Performance of Different Strength Grades of Concrete

作　　者：周启 陈旭勇 程书凯 程子扬 徐雄 ZHOU Qi;CHEN Xuyong;CHENG Shukai;CHENG Ziyang;XU Xiong(School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430074,China;Hubei Engineering Research Center of Green Civil Engineering Materials and Structures,Wuhan 430074,China)

机构地区：[1]武汉工程大学土木工程与建筑学院,湖北武汉430074 [2]绿色土木工程材料与结构湖北省工程研究中心,湖北武汉430074

出　　处：《武汉工程大学学报》2022年第5期534-539,共6页Journal of Wuhan Institute of Technology

基　　金：湖北省重点研发计划项目(2020BAB071);武汉工程大学第十三届研究生教育创新基金(CX2021126);武汉工程大学校内科学基金(K201932,K2021031)。

摘　　要：设计了5种强度等级(C15、C20、C30、C40和C50)的再生混凝土,以3种不同取代率(50%、70%和100%)的再生粗骨料等质量取代天然碎石,研究其对混凝土坍落度、抗压强度、劈裂抗拉强度和拉压比的影响规律,通过扫描电子显微镜分析其微观结构。结果表明:随着再生粗骨料取代率增大,各等级再生混凝土的坍落度增大了10%~11.7%,而其抗压强度和劈裂抗拉强度分别下降了13.6%~17.9%和21.7%~35.6%,拉压比减小了7.1%~22.4%;当再生粗骨料取代率为100%时,高强度等级的再生混凝土界面过渡区中裂缝被水化产物填充,微观结构更加密实。Recycled concretes with five strength grades(C15,C20,C30,C40 and C50)were designed,and three different replacement ratios(50%,70%and 100%)of recycled coarse aggregates were used to replace natural gravel.The effects of recycled coarse aggregate on the slump,compressive strength,splitting tensile strength and the tension-compression ratio of concrete were investigated.The morphologies of interface transition zone of recycled concrete with different strength levels were analyzed by the scanning electron microscopy.The results show that with the replacement rate of recycled coarse aggregate increasing,the slumps of recycled concrete increase by 10%-11.7%,while the compressive strength and the splitting tensile strength decrease by 13.6%-17.9%and 21.7%-35.6%,respectively.Moreover,the tensile-compression strength ratios decrease by 7.1%-22.4%.When the replacement rate of recycled coarse aggregate is 100%,the cracks in the interface transition zone of high strength grade recycled concrete are filled by hydration products and the microstructure is denser.

关 键 词：再生混凝土 再生粗骨料 抗压强度 劈裂抗拉强度 拉压比 界面过渡区 

分 类 号：TU528[建筑科学—建筑技术科学]