摘要
研究了珊瑚砂-水泥砂浆(珊瑚砂浆)的力学性能,以及复合矿物掺和料对珊瑚砂浆的改性作用,并与标准砂浆进行对比.采用扫描电子显微镜-能量弥散X射线谱(SEM-EDS)、X射线衍射(XRD)和傅里叶变换红外光谱(FTIR),对砂浆力学性能、体积稳定性和水化作用的微观机理进行了研究.结果表明:珊瑚砂浆的力学强度低于标准砂浆,加入复合矿物掺和料后可改善水泥石基体及界面过渡区的微观结构,提高珊瑚砂浆的力学性能,使其28d抗压强度较标准砂浆提高了2.1%;珊瑚砂凹凸不平的表面能与硬化水泥浆体形成紧密的啮合状态,有助于提高砂浆的体积稳定性;珊瑚砂的内养护作用使砂浆的力学性能和抵抗收缩能力得到了提高;粉煤灰和矿粉的微集料填充作用和火山灰效应,提高了珊瑚砂浆的力学性能和抗氯离子扩散能力;珊瑚砂持续释放出的Ca^2+、Mg^2+参与了水泥的水化反应,有助于生成更多的水化产物.
Compared with standard sand mortar, the physical and mechanical properties of coral sand mortar(coral mortar, for short), and the effects of mineral admixtures on the coral mortar were investigated. Scanning electron microscope and energy dispersive X-ray spectrometer(SEM-EDS), X-ray diffraction(XRD) and Fourier transform infrared spectrometer(FTIR) were used to explore the microscopic mechanism involved in the mechanical properties, volume stability and hydration of mortar. It is showed that mechanical strength of the coral mortar is lower than that of the standard sand mortar, and the microstructure of cement mortar and interface transition area are improved by the mineral admixture, also the mechanical strength of coral mortar is improved and its 28 d compressive strength is increased by 2.1% as compared to the control. The uneven surface of coral sand can form a tight meshing state with hardened cement mortar, which is helpful to improve the volume stability of mortar. The internal curing effect of coral sand improves the mechanical properties and resistance to shrinkage of the mortar. Furthermore, micro-aggregate filling effect and volcanic ash effect of fly ash and slag improve the mechanical properties and the ability to resist chloride ion diffusion of the coral mortar. The continuous release of Ca^2+ and Mg^2+ from coral sand is involved in the hydration reaction of cement and helps to generate more hydration products.
作者
梅军帅
吴静
王罗新
梅军鹏
丁庆军
MEI Junshuai;WU Jing;WANG Luoxin;MEI Junpeng;DING Qingjun(College of Materials Science and Engineering,Wuhan Textile University,Wuhan 430200,China;Key Laboratory of Textile Fiber and Products(Ministry of Education),Wuhan Textile University,Wuhan 430200,China;State Key Laboratory for Silicate Building Materials,Wuhan University of Technology,Wuhan 430070,China)
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2020年第2期263-270,共8页
Journal of Building Materials
基金
“十三五”国家重点研发计划项目(2017YFB0310100)
湖北省重大专项研发计划(2018AAA001)
固废资源化利用与节能建材国家重点实验室开放基金资助项目(SWR-2016-002)。
关键词
珊瑚砂
力学性能
体积稳定性
微观结构
氯离子
coral sand
mechanical property
volume stability
microstructure
chloride ion
