| SBS and rubber powder are commonly used asphalt modifiers in pavement engineering in recent years,which have a significant improvement on the high temperature anti-rutting and anti-fatigue properties of asphalt.However,due to the low degree of desulfurization of the rubber powder and poor compatibility with the asphalt,the modification effect on the asphalt is poor and the heat storage stability is poor.At the same time,rubber powder swells and absorbs the light component,leads to the high viscosity value and inferior processing ability of modified asphalt.SBS is expensive and easy to float,resulting in meaningful segregation of SBS modified asphalt.To solve the problem of application of SBS and powder problem,based on the theory of density difference,subject to the SBS with powder mixed with asphalt as a modifier,at the same time in order to ensure the full reaction,modifier and asphalt waste engine oil as a surfactant in advance swelling SBS and powder,the waste engine oil,SBS,the temperature sensitivity of modified asphalt and the dosage of powder and the influence of the road.At the same time,SMA-13 gradation,which is commonly used in modified asphalt,is selected for gradation design of asphalt mixture with different amount of waste oil and modifier.The road performance of modified asphalt mixture is evaluated by high-temperature rut test,low-temperature bending test,immersion Marshall test and freeze-thaw split test.This paper selected the five kinds of waste oil content,three kinds of SBS and powder dosage,configured with different surfactant and the dosage of modifier modified asphalt,through different temperature range of temperature sensitivity index normal performance test methods of modified asphalt and asphalt thermal properties and road performance evaluation,at the same time,combined with the optical microscope test and analysis,the mixed surfactant influence mechanism of the performance of modified asphalt,finally determined the surfactant and SBS,powder the optimal mix proportion of two kinds of modifier,namely waste engine oil,rubber powder,the SBS content were 50%,15% and 2.5 % respectively.At the same time,the selection of SMA-13 gap graded mixture gradation design as the foundation,and the modifying agent and different dosage of waste oil is mixed with kinds of modified asphalt road performance test,found that the mixed waste engine oil to the performance of modified asphalt mixture at high-temperature and water stability can have an adverse effect,content lower than 50%,the mixture in the low-temperature crack resistance improved.By comparing the road performance of composite modified asphalt and SBS modified asphalt,it is found that composite modified asphalt has advantages in comprehensive performance and economy. |
