Study On Preparation And Properties Of Liquid Rubber Modified Asphalt

The rubber material is an amorphous polymer,which is elastic at room temperature,can recover shape in time after being subjected to force deformation,and has the characteristics of low glass transition temperature,and is currently widely used in the asphalt modification process.So far,the traditional preparation method of rubber asphalt is to directly put the solid vulcanized rubber particles into the asphalt for agitation,and the obtained modified asphalt can be strengthened at a high temperature,but a high temperature is required in the construction process,and the storage stability is insufficient.In order to solve this kind of problem,researchers have proposed a variety of methods,which can be summarized into three categories: adding chemical powder to chemically crosslink while adding rubber powder,pre-treating and using the rubber powder before putting it into asphalt,and using liquid rubber or rubber latex.At present,the first two modification methods are studied at home and abroad,and the third is rarely reported in China.And in recent years,the liquid rubber modified asphalt abroad can have the excellent performance of the wet rubber modified asphalt.At the same time,it can reduce the construction temperature and make up for the shortcomings of the traditional methods.This paper first collects and summarizes the research status of four types of modified processes including traditional methods at home and abroad,and conducts experimental research on the fourth type of emerging modification methods.The liquid rubber produced in China was used as the modified material,and the orthogonal test was designed to determine the preparation process.The obtained asphalt was evaluated by DSR test,aging test and so on.Four factors and four horizontal orthogonal tests were designed in the study,and the softening point,ductility and rotational viscosity were used as evaluation indexes to determine the relatively superior preparation process.After the artificial aging test,DSR test,BBR test,etc.,it was found that the performance of the modified asphalt prepared by the rubber is not consistent with the foreign research.The high temperature stability is slightly worse than the virgin asphalt,while the low temperature crack resistance and fatigue resistance is greatly enhanced.In addition,during the research process,the change of its performance was similar to that of the aged asphalt.Therefore,the liquid rubber was used as a regenerant.The ZGSB regenerant on the market was used as a control,and the regeneration effect was evaluated by rheological test and artificial aging test.It is found that the high-temperature anti-rutting performance and low-temperature crack resistance of liquid rubber reclaimed asphalt are better,and the anti-fatigue failure performance is closer to that of ZGSB reclaimed asphalt.Finally,the internal structure and modification mechanism were characterized by microscopic test.It was found that the rubber content of the modified asphalt was uniformly distributed in the corrugated area inside the asphalt.During the preparation process,chemical reactions occurred,and the content ratio of saturated alkanes and aromatic hydrocarbons was compared.The improvement is the main reason for its macro performance changes.It can be concluded that the liquid rubber modified asphalt is feasible and the scope of use is more focused on the application of higher requirements for low temperature crack resistance and aging resistance of asphalt.