Research On The Strength And Durability Of CFG Solidified Soil Contaminated With Lead

During these years,soil pollution is increasingly serious problem,and the pollution caused by heavy metal has become a serious environmental geotechnical engineering problems,fly ash and gypsum and other industrial waste have occupied a large amount of land resources and done serious harm to the surrounding environment,to prevent second contamination,it should be utilized synthetically.The paper focused on the soil contaminated with lead and solidified by the mean of CFG through the unconfined compression test,permeability test,accelerated carbonation test and electron microscope experiment,to study on the strength and durability of CFG solidification to the soil contaminated lead,Which provide a reference value for practical engineering of the solidified soil contaminated by lead.The main contents of this study include the following aspects:(1)To analyze that the single factor(Osmotic pressure,CFG content,lead ion concentration)influence on the permeability of solidified contaminated soil.The results show that with the increase of the concentration of lead ion,the permeability of solidified contaminated soil decreases,and with the increase of CFG content,the permeability of solidified contaminated soil increases;(2)After analyzing that the single factor(CFG content,lead ion concentration,maintenance period)influence on the permeability of solidified contaminated soil,and has made exponential fitting for the experimental data and obtained the predictor formula of unconfined compressive strength about CFG solidified soil contaminated with lead.The results show that the unconfined compressive strength of solidified contaminated soil decreases with the lead ion concentration increase.With the increase of CFG content and the increase of age,the unconfined compressive strength of solidified contaminated soil increases;(3)By the analysis of unconfined compressive strength of CFG solidified soil contaminated with lead,and then analyzes the content of CFG,lead ion concentration affect on anti-carbonation performance of CFG solidified soil contaminated with lead,and draw changeable curve of unconfined compressive strength of solidified soil contaminated with lead,and got the compressive strength model of CFG solidified soil contaminated with lead based on accelerated carbonation time.The results show that with the increase of the content of CFG,the carbonation resistance of the contaminated soil is enhanced;(4)SEM was used to analyze the microstructure changes of the solidified contaminated soil during the accelerated carbonation process,and analyze the macro mechanical properties from the microstructure.