摘要
针对高石粉机制砂制备C60自密实混凝土存在的问题,通过对混凝土胶凝浆体组成进行优化,利用硅灰高比表面积特性,分散机制砂中部分石粉,确定了硅灰的最佳掺量为4.5%。研究了砂率对混凝土工作性能的影响,确定砂率为42%。分析了机制砂的石粉含量对混凝土工作和力学性能的影响,石粉含量7%时,混凝土抗压强度达到最高,石粉含量控制在8.1%以下,不会对强度产生较大影响。制备出的混凝土,初始坍落度250 mm,扩展度695 mm,J环扩展度680 mm,3 h坍落/扩展度损失较小,倒坍时间3.4 s,T500为3.0 s,研究成果成功应用于武汉某超高层混凝土工程项目。
The problem of C60 self-compacting concrete prepared by manufactured sand with high content stone powder is optimized.By optimizing the cementitious composition and using the high specific surface area characteristics of silica fume,the stone powder in the sand is dispersed,and the best silica fume content is 4.5%.The effect of sand ratio on the working performance of concrete is studied,and the optimum sand ratio is determined to be 42%.The influence of the stone powder content of the manufactured sand on the work and mechanical properties of the concrete is analyzed.When the stone powder content is 7%,the compressive strength of concrete reaches the highest.When the stone powder content is controlled below 8.1%,the strength will not be greatly affected.It can be determined that the optimum content of stone powder is 8.1%.The concrete prepared by the optimal mix ratio parameters has an initial slump of 250 mm,an expansion of 695 mm,a J-ring expansion of 680 mm,a small loss of 3 h slump/expansion,a collapse time of 3.4 s and a T500 of 3.0 s.The research achievement has been successfully applied to a super high-rise concrete project in Wuhan.
作者
刘凯
张海政
宋正林
周辉
LIU Kai;ZHANG Haizheng;SONG Zhenglin;ZHOU Hui(China Construction Commercial Concrete Co.,Ltd.,Wuhan 430070,China)
出处
《混凝土》
CAS
北大核心
2019年第11期141-144,148,共5页
Concrete
基金
国家重点研发计划“高抗裂预拌混凝土关键材料及制备技术”（2017YFB0310100）
中建股份（CSCEC-2015-Z-38）
关键词
机制砂
石粉
高层泵送自密实混凝土
manufactured sand
stone powder
high-rise pumping self-compacting concrete
