摘要
为探究掺入低活性、高需水比的二级粉煤灰及硅灰的C70高强混凝土的工程应用性能,以花园城C3项目C70高强混凝土为研究对象,设计了不同掺量硅灰及粉煤灰的配合比,并进行了正交对比试验。同时,结合基准配比试验对其进行了优化试验设计,研究表明:1)当二级粉煤灰掺量为95 kg/m^(3)时,C70高强混凝土在基准配合比条件下的工程性能最佳,其混凝土坍落度最大可达210 mm;与常规基准配合比相比,前期强度增幅提高了69.6%,中期强度增幅提升了91.5%,峰值强度达到109.3 MPa;2)在此基础上,通过优化硅灰掺量,采用浓度为35%、掺量为50 kg/m^(3)的液体硅灰,可有效降低混凝土后期收缩开裂风险,且中期峰值强度能达到110.2 MPa,相较于固体硅灰掺量为35 kg/m^(3)时的峰值强度提高了8.23%,经济指标每立方米降低了3.2%,展现出显著的经济效益。本文研究成果可为高强混凝土的工程应用提供一定的参考价值,同时有助于提高工程项目的经济效益,具有重要的推广和指导意义。
In order to explore the engineering application performance of C70 high-strength concrete mixed with secondary flyash and silica fume with low activity and high water demand ratio,the mixing ratio of silica fume and flyash with different dosages is designed with C70high-strength concrete of C3 project in Garden City as the research object,while an orthogonal comparison test is carried out.At the same time,the experimental design of C70 high-strength concrete is optimized according to the benchmark ratio test,and the results show that:1)when the secondary flyash content is 95 kg/m^(3),the engineering performance of C70high-strength concrete is the best under the benchmark mixing ratio condition,and the concrete slump can reach up to 210 mm;Compared with the conventional benchmark mixing ratio,the strength increase in the early stage is increased by 69.6%,the increase in the medium strength is increased by 91.5%,and the peak intensity is reached by109.3 MPa;2)On this basis,by optimizing the silica fume content,using liquid silica fume with a concentration of 35%and a content of 50 kg/m^(3),the risk of shrinkage and cracking of concrete in the later stage can be effectively reduced,and the peak strength in the medium term can reach 110.2 MPa,which is 8.23%higher than that when the solid silica fume content is 35 kg/m^(3),and the economic index is reduced by 3.2%per cubic meter,showing significant economic benefits.The results can provide a certain reference value for the engineering application of high-strength concrete,while help to improve the economic benefits of engineering projects,which has important promotion and guiding significance.
作者
杨云龙
奚欢欢
范长利
汪林华
龚玉亮
YANG Yunlong;XI Huanhuan;FAN Changli;WANG Linhua;GONG Yuliang(Chengdu Construction Engineering Rong Rui Building Materials Co.,Ltd.,Chengdu 610000,Sichuan,China;Jiangxi Jinsheng High-Tech Development Co.,Ltd.,Nanchang 330100,Jiangi,China)
出处
《工程建设》
2025年第7期29-34,共6页
Engineering Construction
关键词
C70高强混凝土
工作性能
优化试验
工程应用
C70 high-strength concrete
working performance
optimization experiment
engineering application
