甘肃省某工程项目机制砂混凝土孔结构研究  

Study on Pore Structure of Machine-Made Sand Concrete in a Project in Gansu Province

作　　者：邹海发 ZOU Haifa(Gansu Province Fifth Construction Group Co.,Ltd.,Tianshui 741000,China)

机构地区：[1]甘肃省第五建设集团有限责任公司,甘肃天水741000

出　　处：《河南科技》2023年第17期74-77,共4页Henan Science and Technology

摘　　要：【目的】为研究在甘肃省部分地区恶劣自然环境下与工程同条件养护下的花岗岩机制砂混凝土孔结构分布情况。【方法】依托于实际工程项目,设计了多组不同石粉含量的机制砂混凝土,并且进行同条件养护。达到设计龄期后,通过抗折强度试验、气孔结构分析及核磁共振试验(NMR),对混凝土力学性能及孔隙分布进行了研究。【结果】结果表明:机制砂中石粉含量小于8%时,随着石粉含量的增大,混凝土抗折强度增大,内部孔隙率与孔隙尺寸降低;石粉含量大于8%时,混凝土抗折强度降低,内部孔隙率与孔隙尺寸增大;石粉含量为8%时,混凝土抗折强度达到最大值,且内部孔隙率与孔隙尺寸较小。【结论】在甘肃省部分地区应用花岗岩机制砂时,其石粉含量宜控制在8%左右。[Purposes]This paper aims to study the pore structure distribution of granite machine-made sand concrete under the same conditions of maintenance in harsh natural environment in some areas of Gansu Province.[Methods]Based on the actual engineering project,multiple sets of manufactured sand concrete with different stone powder contents were designed and maintained under the same comditions.After reaching the design age,the mechanical properties and pore distribution of concrete were studied by flexural strength test,pore structure analysis and nuclear magnetic resonance(NMR)test.[Findings]The results show that:when the content of stone powder in manufactured sand is less than 8%,with the increase of stone powder content,the flexural strength of concrete increases,and the internal porosity and pore size decrease;when the content of stone powder is more than 8%,the flexural strength of concrete decreases,and the internal porosity and pore size increase;when the stone powder content is 8%,the flexural strength of concrete reaches the maximum value,and the internal porosity and pore size are small.[Conclusions]The content of stone powder should be controlled at about 8%when the granite machine-made sand is applied in some areas of Gansu province.

关 键 词：混凝土 机制砂 石粉含量 孔隙分布 

分 类 号：TU528[建筑科学—建筑技术科学]