海洋环境下镍铁渣粉水泥土强度增强的微观机理研究

Study on the microscopic mechanism of strengthening of cement soil with ferronickel slag powder in marine environment

为了从微观结构上研究镍铁渣粉在海洋环境下对水泥土强度增强的机理,采用压汞(mercury intrusion porosimetry,MIP)法、X射线衍射(diffraction of X-rays,XRD)法、扫描电子显微镜(scanning electron microscope,SEM)法和能谱仪(energy dispersive spectroscopy,EDS)法对镍铁渣粉水泥土进行了试验研究,结果表明:掺入到水泥土的镍铁渣粉能发挥出微集料效应和活性效应、减小水泥土的最可几孔径和总孔隙率,进而缓解海洋环境对水泥土孔隙结构的劣化;镍铁渣粉能较好地发挥其活性效应,能促进生成具有低Ca/Si的水化产物,改善水泥土的组成和微结构,使水泥土结构更密实,有利于提升水泥土的强度,从而缓解海水的侵蚀作用。

In order to study the mechanism of ferronickel slag powder's strength enhancement of cement soil in the marine environment from the microstructure,mercury intrusion porosimetry(MIP),X-ray diffraction(XRD),scanning electron microscope method(SEM)and energy dispersive spectroscopy(EDS)were used to analyze the characteristics of the nickel iron slag powder cement soil.The results show that the nickel-iron slag powder mixed into cement soil can exert micro-aggregate effect and active effect,reduce the most probable pore size and total porosity of cement soil,thereby alleviate the deterioration of the pore structure caused by the marine environment.Ferronickel slag powder can exert its active effect well.Ferronickel slag powder can make the microstructure of cement soil more compact,and at the same time can promote the formation of low Ca/Si hydrates product and enhances its cohesion,which is conducive to the improvement of the strength of cement soil,so as to alleviate the erosion of seawater.