复掺粉煤灰与石灰石粉的外掺氧化镁碾压混凝土性能研究  

Study on the Performance of MgO⁃Admixed RCC Codoped with Fly Ash and Limestone Powder

作　　者：陈荣妃[1] 陈昌礼[1] 杨华山[1] 赵振华[1] 刘小萤[1] CHEN Rongfei;CHEN Changli;YANG Huashan;ZHAO Zhenhua;LIU Xiaoying(School of Materials and Architecture Engineering,Guizhou Normal University,Guiyang 550025,China)

机构地区：[1]贵州师范大学材料与建筑工程学院,贵州贵阳550025

出　　处：《人民黄河》2023年第10期131-135,共5页Yellow River

基　　金：国家自然科学基金资助项目(51869005);贵州省科技计划项目(黔科合平台人才[2018]5769-25);贵州省科技计划项目(黔科合基础-ZK[2023]一般261);贵州省教育厅高等学校科学研究项目(黔教基[2022]134号)。

摘　　要：为促进外掺氧化镁(MgO)碾压混凝土筑坝材料在粉煤灰资源匮乏地区的推广应用,本着就地取材的原则,研究了复掺粉煤灰与石灰石粉的外掺氧化镁碾压混凝土的力学性能、自生体积变形性能和微观结构。结果表明:在相同MgO掺量下,与单掺粉煤灰的外掺MgO碾压混凝土对比,复掺粉煤灰与石灰石粉的外掺MgO碾压混凝土的自生体积变形增大,但随石灰石粉取代粉煤灰量的增加而减小;龄期28、90 d的抗压强度、劈拉强度和极限拉伸值均减小;无害孔和少害孔增多,孔隙得到细化,微观结构良好。石灰石粉可以部分取代粉煤灰应用于外掺MgO碾压混凝土,石灰石粉取代粉煤灰的数量宜控制在20%以内。In order to promote the popularized application of magnesia(MgO)roller compacted concrete(RCC)dam material in the areas where fly ash resources are scarce,and in line with the principle of using the locally-produced raw material,the mechanical properties,au-togenous volume deformation properties and micro-structure of MgO-admixed RCC codoped with fly ash and limestone powder were studied.The results indicate that compared with singly-doped fly ash,the autogenous volume deformation of MgO-admixed RCC codoped with fly ash and limestone powder increases with the same amount of MgO,but decreases with the increase of the amount of limestone powder replacing fly ash;the compressive strength,splitting tensile strength and ultimate tensile value decrease at 28 d and 90 d;the increase of harmless pores and less harmful pores leads to the refinement of pore size,and the micro-structure is well.Limestone powder can partially replace fly ash in MgO-admixed RCC and the amount of limestone powder instead of fly ash should be controlled within 20%.

关 键 词：石灰石粉 粉煤灰 力学性能 自生体积变形 微观结构 外掺MgO碾压混凝土 

分 类 号：TV32[水利工程—水工结构工程]