不同强度等级下再生混凝土的力学及路用性能研究  

Research on mechanical and road performance of recycled concrete under different strength grades

作　　者：张爱丽[1] 田光辉 郭颜凤 ZHANG Aili;TIAN Guanghui;GUO Yanfeng(Department of Architecture and Civil Engineering,Anyang Vocational and Technical College,Anyang 455000,China;College of Architecture and Engineering,Zhongyuan University of Technology,Zhengzhou 450007,China)

机构地区：[1]安阳职业技术学院建筑工程系,河南安阳455000 [2]中原工学院建筑工程系,河南郑州450007

出　　处：《混凝土》2023年第12期192-195,共4页Concrete

摘　　要：研究了不同强度等级下再生粗集料混凝土的抗压、劈裂等力学性能及水泥稳定性、低温开裂性能,用灰色关联度分析了各参数对28 d抗压强度的影响。结果表明:随着养护龄期的延长,4组再生混凝土的抗压强度和劈裂强度均呈现上升趋势,龄期14~28 d时的抗压强度和劈裂强度增长率明显高于28~56 d的强度;RC50相对于RC20、RC30、RC40的最大干密度分别增加了10.6%、8.3%、7.2%,最佳含水率分别减小了20.4%、14.3%、3.7%;随着再生混凝土强度的提高,开裂厚度和宽度有小幅降低,混合料的弯曲应力、断裂载荷和弯曲模量有较为明显的提升;灰色关联分析表明再生混凝土各参数对28 d抗压强度的影响最大的为弯曲应力。The mechanical properties of recycled coarse aggregate concrete under different strength grades such as compression and splitting,cement stability,and low-temperature cracking properties are studied.The effect of each parameter on 28 d compressive strength is analyzed with grey correlation.The results show that with the extension of the curing age,the compressive strength and splitting strength of the four groups of recycled concretes all show an upward trend,and the growth rate of the compressive strength and splitting strength at the age of 14~28 d is significantly higher than that of 28~56 d.The maximum dry density of RC50 relative to RC20,RC30,and RC40 increased by 10.6%,8.3%,7.2%,and the optimal moisture content decreased by 20.4%,14.3%,and 3.7%,respectively.With the increase of strength,the cracking thickness and width are slightly reduced,and the bending stress,breaking load and bending modulus of the mixture are significantly improved.As the strength of recycled concrete increases,the strength of recycled coarse aggregate also increases.The tendency of cohesion to increase is more obvious,so the bending stress,fracture load and bending modulus between the interfaces are increased;Grey relational analysis shows that the bending stress has the greatest influence on the 28 d compressive strength of recycled concrete parameters.

关 键 词：再生混凝土 抗压强度 劈裂强度 水泥稳定性 低温开裂 灰色分析 

分 类 号：TU528.01[建筑科学—建筑技术科学]