Research On Design Of Micro-surfacing Mixture And Gradation Optimization

With the rapid development of highway in china, many freeways have been in maintenance period.more and more attention has been draw upon asphalt pavement maintenance of freeway.it is important to do some research work and to popularize economic, effective and convenient preventive maintenance methods.Micro-surfacing is an economical preventive maintenance technic,it can be easily constructed and the taffic can be opened quickly.it can renovate rutting and has long usage life.it has been widely used in overseas and gained ever-growing attention in china .In order to use effectively Micro-surfacing on preventive maintenance and design the mixture quickly according to different requirement of application. The importance of preventive maintenance and design requirements and design procedure were discussed, Analysis on important index during aggregate selection and problems in determing asphalt content had done Through the comparative analysis of service condition of Micro-surfacing at home and abroad, eight gradations were selected . Through mixing test, breaking time test and cohesion test. it was concluded that the operable time of coarse gradation is better than fine gradation's, forming velocity of fine gradation is better than coarse gradation's. Through wet track abrasion test,load wheel test and stability and resistance to compaction test , it was concluded that wear-ability and water stability of fine gradation are better than coarse gradation's,anti-slide performance and rutting resistance of coarse gradation are better than fine gradation's,According to gray system theory, the gradation that has better pavement performance was chosen...