| With the development of the automobile industry,disposal of waste tire rubber has become a major environmental issue in all parts of the world..For the last years,construction industry is taking up the challenge to incorporate sustainability in the production activities by searching for more environmental friendly raw materials.One of the possible solutions for the use of waste tire rubber is to incorporate into cement soil,which will improve its frost resistance and also significantly improve the bearing performance as a kind of foundation material.However,few research has investigate the area of the permeability of rubber cement soil(RCS).Therefore,this article mainly studied the permeability of rubber-cement soil,and also analyzed the rubber characteristics by using several different modification methods.As a result,the findings will provide a theoretical basis for the application of rubber-cement soil in practical projects such as foundation pits and soft soil foundations in rainy areas.The characteristics of different RCS were investigated.This project would focus on the following studies:(1)Carry out consolidation test and permeability test on rubber cement soil.The main research variables are water content,cement content,rubber powder content,and age.The results show that the increase in the amount of rubber powder can improve the permeability of cement soil,and the rubber powder with a particle size of 40 mesh can effectively reduce the medium and small pores in the cement soil;the increase in water content has an adverse effect on the permeability of rubber cement soil;(2)Considering that during the penetration test,the sealing problem between the test piece and the metal test mold may cause water seepage on the sidewall.In order to simplify the test process and lay a foundation for the determination of the permeability coefficient of rubber cement soil under known conditions,the test found that cement There is a good linear correlation between the content and age and the permeability of cement-soil.Therefore,a prediction model for the permeability coefficient of rubber-cement soil under the combined effect of cement content and age is established;and the void ratio is established for permeability Coefficient prediction formula;(3)In order to study the relationship between the void ratio and the permeability coefficient,the study found that with the increase of the consolidation pressure,the permeability performance is better improved,and there is a good linear relationship between the void ratio and the permeability coefficient;(4)Unconfined compressive strength is one of the most basic main mechanical properties.The unconfined compressive strength test of rubber-cement soil is carried out.The incorporation of rubber powder has an adverse effect on the compressive strength,but the test results show that,There is a good one-to-one correspondence between unconfined compressive strength and permeability coefficient;(5)In order to improve the adhesion between rubber powder and soil particles and further strengthen the influence of rubber powder on the permeability of cement soil,three methods of pretreatment of rubber powder with water and sodium carbonate solution and silica fume were studied.The effect of the modification on the performance of cement-soil was studied.After pretreatment,the permeability and unconfined compressive strength of rubber cement soil have been improved,but the effect of water pretreatment on the performance of the specimen is not obvious;the performance of rubber cement soil after silica fume pretreatment has been improved Better improvement;the effect of different pretreatment methods is greatly affected by the cement content. |
