Experimental Study On Engineering Characteristics Of Dispersed Loess Modified By Slag Powder

Dispersed soil has low erosion resistance and shows easy dispersion properties in water,which is easy to cause engineering accidents such as dam pipe surge and embankment instability,while dispersed soil is widely distributed in China and should.attract sufficient attention.Iron and steel smelting will produce industrial waste residue such as blast furnace slag,and the main ways of waste slag recycling are as cement incorporation material,filling material,soil improvement,etc.In this paper,the slag powder is used as the soil modified material,and the dispersion,mechanical properties and modification mechanism of the slag micro-powder modified dispersed soil are studied,and the main research results are as follows:(1)The addition of slag micro-powder in the dispersed soil can improve the dispersion of the soil,the increase in the amount of slag powder can reduce the dispersion of the soil,and the dispersion of the soil body will gradually decrease after the extension of the maintenance age,and it is recommended that the amount of slag powder mixing be controlled at 7%and the maintenance for more than 7d in the application of damming and packing.(2)The unconfined compressive strength of the modified soil increases with the increase of slag powder mixing,and when the maintenance time is shorter,the increase of slag powder doping has little effect on the strength of the modified soil,and when the maintenance time is longer,the higher amount of slag powder can increase the strength of the modified soil significantly;The maintenance time of modified soil is increased,and the strength of soil is increasing.The increase in the amount of slag powder mixing showed a negative correlation with the amount of compression deformation of the modified soil.The increase in maintenance time was negatively correlated with the amount of compression deformation of the modified soil.With the increase of slag powder mixing,the permeability coefficient of the modified soil gradually decreases.(3)After the slag powder is added to the dispersed soil,the microstructure of the dispersed soil changes.With the increase of slag powder mixing,the total area of pores decreases significantly,and the small and medium pores gradually disappear.The cementitious material produced under the action of slag micronized fills the pores,so that the small and medium pores are converted into micropores,and the number of micropores is increased,so that the compactness of the soil is improved.(4)Slag powder is added to the dispersed soil sample,hydration reaction and ion replacement reaction occur,by reducing the thickness of the double electric layer,the formation of cementitious material makes the soil particles become tight,filling the pores of the soil body to reduce the dispersion of the soil and improve the mechanical properties of the soil.In summary,through indoor experiments,the dispersion,mechanical properties and microscopic characteristics of modified dispersed soils with slag micronized powder were studied,which provided theoretical support for the application of slag micropulverized modified dispersed soils.