Study On The Mechanism Of Lime Modified Red Clay Based On Fractal Theory

On red clay high natural moisture content,high liquid limit,plastic index,the water of the characteristics of big deformation in Guangxi Mailing(Xiang-gui bound)to congratulation state along the highway engineering of red clay,for example,from a liquid limit,plastic limit and plasticity index three aspects elaborated by different dosage of lime improved limit moisture content change characteristics of red clay,compaction test、CBR test and direct shear test at the same time,analysis the different dosage of lime improved the mechanical properties of red clay characteristics;In addition,SEM test was carried out,and fractal theory was used to study the change law of fractal dimension of particle structure of lime-modified red clay,such as particle distribution,size and shape,and then the microscopic mechanism of lime-modified red clay was analyzed.After research,the following results are obtained:(1)Through limit moisture content test,compaction test,CBR test and direct shear test of different dosage of lime improved under the red clay’s liquid limit,plasticity index,maximum dry density,CBR value and the change of physical and mechanical properties such as shear strength are studied,through the analysis of a large number of experimental results,to get the optimum content of lime improved red clay is 7%,when the dosage of lime is 7%lime improved road of red clay is the best.(2)Combined with the SEM test and the X-ray diffraction test,the mineral structure,ion exchange reaction and cementation mechanism of the soil were analyzed under the condition of red clay and different lime contents.The image processing technology was used to process the SEM images before and after the lime modified red clay,and the microstructure of soil particles(such as the distribution,size and shape of soil particles)in the processed SEM images was studied and analyzed by combining with the fractal theory.(3)Combined with microscopic particles of soil structure of three kinds of fractal model,the granularity fractal dimension is calculated respectively,and the circular degree of fractal dimension and fractal dimension of particle distribution,the analysis of the lime improved the fractal dimension of red clay with lime dosage,the characteristic of quantitative analysis and lime improved red clay microstructure before and after the change rule of performance.(4)The change of micromechanical properties of red clay modified by lime was studied based on the theory of double electric layer.Based on the changes of the double-layer structure of red clay particles and the thickness of the bound water film before and after the lime improvement,this paper analyzes the changes of the bound water property in the soil and the reasons for the thinning of the bound water film thickness,so as to better understand the mechanism of the lime improvement of the red clay.