A Study On The Pavement Performance Of Hot In-place Recycled Modified Asphalt And HMA

The modified asphalt has been widely used in high-grade highway since 1990s, with the rapid development of road construction in China. The aging of modified asphalt and fining of aggregate turn serious and the pavement performance decreases under the effects of both vehicle load and natural factors, even affecting the safety of driving. Therefore, the modified asphalt pavement must be maintained after years of service. The mailed old mixture would be a kind of pollution of environment and waste of resources. The recycle of old asphalt mixture attracts concern of engineering field. The recycle of base asphalt mixture has already been applied, but the researches on the recycle of modified asphalt mixture are relatively few.The following four aspects are researched in this paper, based on the pavement maintenance project of Shenyang to Shanhaiguan highway (SMA-16):component analysis of extracted aging asphalt and recycle scheme research, selection and test of regeneration agent for modified asphalt, research of mix design and test on recycled modified asphalt pavement performance. The regeneration agent for modified asphalt developed by the Communications Research Institute of Liaoning Province is used in the research of regeneration agent. The proportion of regeneration agent is fixed 7.1% with the index of penetration. The pavement performance is proved fine by tests. The Marshall Test is given to determine that the gradation satisfies the requirement when the proportion of old mixture is 90% and optimum asphalt proportion is 6.2%, respectively testing the proportion at 80%,85% and 90%. Then, the pavement performance tests are carried out, such as rutting test, freeze-thaw cycle test and low-temperature bending test. The results show that the recycle asphalt mixture with 90% aging materials can satisfy the requirement of specification.