Research On Engineering Properties Of Magnesium Phosphate Cement Solidified/Stabilized Cu Contaminated Soils

With the rapid advancement of urbanization and industrialization in China,problems such as environmental pollution,resource scarcity and ecological destruction are imminent.Among them,the problem of heavy metal contaminated soil has become a topic of great concern to experts and scholars in the field of environmental geotechnical and engineering fields.The method of repair and processing.In the aspect of heavy metal pollution repair,research shows that magnesium phosphate cement is not only a fast-hardening repair material,but also a new type of curing stabilization material.In this paper,magnesium phosphate cement solidified heavy metal copper contaminated soil was taken as the research object.Through the unconfined compressive strength and toxic leaching(TCLP)test,the magnesium phosphate cement content,the curing age,the initial concentration of Cu2+in contaminated soil were studied respectively.The engineering properties of cement-cured copper contaminated soil;the resistivity test and scanning electron microscopy(SEM)technique were used to analyze the solidification and variability mechanism of magnesium phosphate cement-cured copper contaminated soil.The specific research contents are as follows:(1)Conducting unconfined compressive strength test of solidified contaminated soil,and researching different magnesium phosphate cement content(5,10,15,20%),different curing ages(3,7,28,90d),different Under the condition of initial copper ion concentration(0,0.1,0.5,1.0,2.0%)of contaminated soil,the strength of heavy metal contaminated soil was solidified by magnesium phosphate cement,and the mechanism of property variation was discussed.(2)Conducting toxic leaching test to analyze the initial copper ion concentration of different contaminated soils,not using magnesium phosphate cement,and the concentration of copper ions in leaching filtrate under different curing ages,to determine the toxicity standard of China(GB5085.3-2007)Based on the basis,explore the curing effect and draw a reasonable curing plan.(3)Conducting the resistivity test to investigate the resistivity of the initial copper ion concentration,the different magnesium phosphate cement content and the different curing ages of different contaminated soils,and qualitatively analyze the mechanism of action of magnesium phosphate cement solidified heavy metal contaminated soil.And analyze the relationship between compressive strength and resistivity.(4)The electron microscopy scanning test of the solidified soil was carried out to analyze the influence of different magnesium phosphate cement content,different curing ages and different copper ion concentrations on the microstructure,and quantitative analysis of the compressive strength of the solidified soil and the percentage of internal pores.relationship.