摘要
采用废弃特细砂(TQS)改性石灰石机制砂(LS)并取代部分天然砂(QS)制备C60高性能混凝土,研究了混合砂中特细砂掺量对C60混凝土性能的影响,采用XRD和SEM分析不同砂的化学组成、颗粒形貌。结果表明:当TQS掺量≤15%时,可对LS进行级配优化,通过调整砂比例、级配和外加剂掺量,可配制工作性能和流变性能良好的C60混凝土;特细砂可提高QS+LS+TQS体系的堆积密实性,使混凝土中骨料框架更加稳定,TQS掺量≤15%时,可提高混凝土的抗压强度、抗折强度和弹性模量;砂颗粒级配、形貌和岩性对混凝土抗冻性影响较小,抗冻等级>F400,满足高性能混凝土需求;TQS改性LS后部分取代QS,可提高混凝土的抗收缩性能,QS+LS+TQS体系干燥收缩较QS、LS和TS体系略低,总体上,QS、LS和TS体系的干燥收缩相近。
In this paper,experiments on preparing C60 high performance concrete with waste super-fine sand(TQS)modified manufactured sand(LS)to partially replace natural sand(QS)were investigated.The influence of ultra-fine sand content in mixed sand on the performance of C60 concrete was studied.The chemical composition and particle morphology of different sands were analyzed by XRD and SEM.The results show that the gradation of manufactured sand can be optimized by modifying the amount of TQS not more than 15%.C60 concrete with good working performance and rheological properties can be prepared by adjusting the proportion and gradation of sand and the amount of admixture.The addition of TQS improves the compactness of QS+LS+TQS particles,which makes the aggregate frame in concrete more stable.It is found that the compressive strength,flexural strength and elastic modulus of concrete can be improved when TQS dosage is not more than 15%.The gradation,morphology and lithology of sand particle grading have little influence on the frost resistance of concrete,and the frost resistance grade of concrete is greater than F400,which can meet the high performance requirements.TQS partially replaces QS after modifying LS,which can improve the shrinkage resistance of concrete.The dry shrinkage of QS+LS+TQS is slightly lower than that of QS,LS and TS concrete,but generally the dry shrinkage of QS,LS and TS concrete is similar.
作者
王方刚
陆加越
赵少鹏
施展
刘建忠
WANG Fanggang;LU Jiayue;ZHAO Shaopeng;SHI Zhan;LIU Jianzhong(Jiangsu Subote New Materials Limited Company,Nanjing 211103,China;State Key Laboratory of High Performance Civil Engineering Materials,Nanjing 210008,China)
出处
《新型建筑材料》
2022年第7期22-27,31,共7页
New Building Materials
基金
南京市科技计划国际联合研发项目(202002027)。
关键词
机制砂
特细砂
高性能混凝土
力学性能
干燥收缩
manufactured sand
super-fine sand
high performance concrete
mechanical property
dry shrinkage
