Study On The Application Of Bentonite Emulsified Asphalt In Lanfill

In recent years,the problem of landfill leakage is becoming more and more serious,which is a major aspect of environmental pollution.Landfill leachate will be produced after landfilling,and its composition is complex.If natural clay is used alone as the landfill base material,its strength is low and its resistance to chemical corrosion is poor,which can not meet the requirements.Therefore,the research on new materials is of great significance.Bentonite emulsified asphalt is a good anti-seepage material,and has a certain degree of corrosion resistance.The bentonite in bentonite emulsified asphalt also has a certain degree of adsorption,which can adsorb heavy metal ions in leachate,and the cement has high strength after hydration.In this paper,the effects of bentonite emulsified asphalt and cement modified soil on unconfined compressive strength,shear strength,cohesion,internal friction angle and permeability of clay are studied,and the mechanism is analyzed.The specific research contents are as follows:(1)Preparation of bentonite emulsified asphalt: firstly,the emulsifying time,p H value,temperature,oil-water ratio range and other test conditions are determined;secondly,the emulsified asphalt is prepared by adding different amounts of bentonite,different kinds of active agents and stabilizers,and the viscosity,storage stability,softening point of evaporation residue,penetration of emulsified asphalt are determined,finally the selection of polyethylene glycol is determined The emulsified asphalt is prepared by using enol as stabilizer,sodium dodecyl sulfate and OP-10 as activator;finally,the emulsified asphalt with good performance is prepared by orthogonal test,through the detection of evaporation residue content,softening point,penetration and ductility of emulsified asphalt,so as to determine the amount of emulsifier,activator and asphalt solid content.(2)As the base material of landfill,it should not only meet the requirements of permeability coefficient,but also have certain compression and shear resistance.The unconfined compressive strength,shear strength,cohesion and internal friction angle of the specimens were tested with different amounts of bentonite emulsified asphalt and cement and different curing ages,and the shear results were fitted.Finally,the experimental data show that the compressive strength,shear strength,cohesion and internal friction angle gradually increase with the increase of cement content and age,and first increase and then decrease with the increase of emulsified asphalt.(3)The specimens with different cement content and bentonite emulsified asphalt content were cured in sewage and clean water respectively,the change law of material permeability coefficient under different curing age was studied,and the action mechanism of cement and emulsified asphalt on enhancing the performance of clay was analyzed.The results show that the addition of Bentonite emulsified asphalt and cement can improve the permeability of clay,and the effect of bentonite emulsified asphalt and cement on the permeability of clay is obvious in sewage In the case of medium curing,the addition of bentonite emulsified asphalt can resist the erosion of some heavy metal ions.Through the study of this paper,it is considered that bentonite emulsified asphalt can be used in landfill liner,and it can play the role of solidification and anti-seepage characteristics of landfill base with cement.The research results of this paper provide a new material for the foundation engineering of landfill,and develop a new use of bentonite emulsified asphalt.The data and conclusions obtained through the test can provide theoretical basis and reference value for the actual engineering.