Research On Modification Mechanism Of Rubber Asphalt Prepared By Microwave Activated Rubber Powder

Waste tires are the most important solid waste in the automotive industry,which put tremendous pressure on eco-environmental protection.As an environmentally friendly high-quality road engineering new materials,rubber asphalt has good effect in consuming waste tire powder and improving the level of road traffic service,but the storage stability is poor,the construction of poor flexibility is restricting the promotion of rubber asphalt application.Therefore,how to improve the stability of rubber asphalt and the workability of the rubber asphalt,extend the service life of asphalt pavement and improve the level of asphalt pavement service will become an urgent problem in road engineering.The use of activated rubber powder to produce modified asphalt provides a solution to the above problemsThis paper will analyze microwave activation method that is used to activate the waste rubber powder for the preparation of rubber asphalt,and asphalt screen is utilized to produce asphalt binder without rubber powder.Brookfield viscometer(BV)and Dynamic Shear Rheological(DSR)are then applied to study the road performance of rubber asphalt.On this basis,the preparation technology and parameters of high performance rubber asphalt were recommended.The results show that the modified powder has the best viscosity and high temperature stability when the waste tire powder is activated for 90 seconds.The complex shear modulus of activated asphalt modified asphalt is positively correlated with the existence of IE,and the higher the IE is,the larger the corresponding complex modulus is;the complex shear modulus value is linearly correlated with the corresponding PE,the higher the PE,the larger the corresponding complex shear modulus value.Through scanning Electron Microscopy(SEM)and specific surface area of waste tire powder were tested,we can analyze the influence of the apparent morphology of the microwave activated waste tire powder and the change of the specific surface area.Experiments show that microwave irradiation increases the number of micropores in the powder,which increases the specific surface area of the powder.After microwave treatment,the particle size of the powder particles become smaller and the surface pores were increased.With the increase of the microwave treatment time,the agglomeration of the particles increases,and the surface pores are denser.After the microwave treatment,the powder begins to swell and the pores increased,and the specific surface area increased.The molecular weight of activated asphalt modified asphalt was studied by Gel Permeation Chromatography(GPC).The relationship between the content of macromolecules,medium molecules,and modified asphalt in activated asphalt modified asphalt can be analyzed,and the relationship between IE,PE and molecular weight can be studied.The results show that LMS is positively correlated with the IE value of viscosity and complex shear modulus,that is,the IE value of viscosity or complex shear modulus increases with LMS,the effect of the filling of the powder particles in the asphalt on LMS should be small.The mass change and thermal stability of activated asphalt modified by asphalt were analyzed by Differential Scanning Calorimetry(DSC).The experimental results show that microwave activation can improve the high temperature stability of rubber asphalt.