Study On Micro-characteristics And Performance Of Car Tires Rubber Powder Modified Asphalt

In recent years,rubber asphalt has been widely used in our country because of its good high and low temperature performance and aging resistance.However,rubber asphalt still has its own limitations and shortcomings,mainly as a single source of rubber powder and lack of desulfurization.At present in our country,truck tires are the main modifier powder types for producing modified asphalt,car tires are less used,so the recovery and utilization of car tires have become a big problem,and even though the twin screw extruder have solved the problem of low degree of desulfurization of the powder,the high extrusion temperature will not only reduce the mechanical properties of rubber powder,but also bring pollution and energy consumption problem.To solve the car tire powder difficult to use and energy consumption,pollution problems when used high temperature in extruding,it is intended to combine the waste oil activation and screw extrusion to deal with the car tire powder,so as to achieve the purpose of reducing the extrusion temperature,saving energy consumption,reducing pollution and obtaining the ideal recycled rubber.Firstly,the effects of regeneration process,the ratio of powder / additive blending ratio and the extrusion temperature on the microscopic characteristics such as the degree of desulfurization and the temperature-quality change were analyzed by means of extraction test,infrared spectroscopy test and thermogravimetric analysis.It is found that the desulfurization effect of waste oil is remarkable.With the increase of the amount of waste oil and the temperature of extrusion,the decomposition temperature of the characteristic material in the powder decreases,the rubber powder become more easily decomposed.Secondly,the conventional performance tests(including penetration,softening point,extension,viscosity,segregation)and high and low temperature performance of rubber asphalt tests with different regeneration technology,powder / additive blending ratio,extrusion temperature and powder content were carried out.Combined with the micro-change of the powder and tests result to get the best powder / additivesblending ratio and extrusion temperature.The optimal ratio of powder / additive blending and the extrusion temperature were 3: 1 and 180?,respectively.At the same time,in order to ensure the processing of rubber asphalt,the highest content of powder should not exceed 30%.Finally,the fluorescence microscopy images of various rubber asphalt were processed and analyzed by using special image processing software Image-J,and we can establish the relationship between the average area,average particle size and percentage of total area and rubber asphalt road performance.The results show that the microscopic characteristic value of rubber asphalt is well correlated with macroscopic performance,and the microscopic characteristic value can reflect the change of macroscopic index reasonably.