Study On Road Performance Of Modified Bio-asphalt And Its Mixture

As a large number of high-grade highway asphalt pavements in China begin to be refurbished,renovated and expanded,a large number of RAPs have not been effectively utilized,and accumulation everywhere affects the environment.After mixing and regeneration,SBS modified asphalt with different dosage is added to study the performance changes of the mixture.On the one hand,modified regeneration technology can improve the relevant performance of the recycled material and increase the RAP utilization rate.On the other hand,the addition of warm mixing technology can reduce the heat The mixing temperature of the recycled asphalt mixture is better adapted to the development concept of green transportation.In order to obtain a reasonable dosage under the combined action of SBS modifier and RAP,the performance of the raw materials used in the test is tested to ensure that the recycled materials meet the regeneration requirements;theoretically analyze the asphalt aging and regeneration mechanism,and simulate the preparation of aging through 360 minutes of RTFOT rotation Asphalt,and regenerate by adding regenerant,determine the reasonable amount of regenerant to account for 10%of the old asphalt content,and then add 3%,4%,5%SBS modifier to reconcile the aging asphalt after regeneration,The results can be restored to the performance requirements of SBS modified asphalt;design the mixture ratio of RAP blended at 40%,50%and 60%,and use the Marshall test to determine the optimal oil-rock ratio to be 4.8%,4.9%and 5.0%respectively The variable temperature compaction test determined that the mixing and compaction temperatures were 135?,135?,and 145?,respectively.Finally,the performance of the warm-mixed recycled asphalt mixture with different amounts of SBS modifier added is studied.The results show that:in terms of high temperature performance,the increase in the SBS and RAP content will make the warm-mixed recycled asphalt mixture have better high-temperature performance Both of them are improved and meet the requirements of the specification.In terms of low temperature performance and water stability performance,the comprehensive freeze-thaw split test strength ratio and residual stability are considered together.The RAP content of the warm-mixed recycled asphalt mixture is 50%and the SBS content is At 5%,it meets the requirements of the specification for modified asphalt;in terms of fatigue performance,the amount of RAP increases,the fatigue performance decreases by a large extent,the amount of SBS increases,and the fatigue performance continues to improve.Considering all performances and operating costs,it is recommended that the RAP content of the warm-mixed recycled modified asphalt mixture should not exceed 50%,and it is best to use 5%SBS modifier.