Study On Modification Method And Road Performance Of Granite Asphalt Mixture

With the development of road construction and the awareness of environmental protection,alkaline aggregates with excellent performance and non-renewable capacity are also rapidly decreasing.China’s granite reserves are abundant,with the advantages of high mechanical strength,good wear resistance and strong fatigue resistance.For example,the application of granite to asphalt pavement can not only solve the problem of insufficient alkali aggregate resources,but also drive local economic development.However,the adhesion between granite and asphalt is poor,and there are problems such as insufficient water stability,which seriously restricts the application and promotion of granite on asphalt pavement.Therefore,it solves the water damage resistance of granite asphalt mixture and maintains or improves other road performance.It will be of great significance and value to the construction of highways in our province and the conversion of new and old kinetic energy.At present,lime water pretreatment aggregate,lime powder replacement part of mineral powder,Qingchuan rock asphalt,amine anti-stripping agent and other measures are generally used to improve the adhesion of granite and asphalt and the water stability of asphalt mixture.However,lime water treatment aggregates need to improve equipment,complicated process,and poor durability after water treatment.The low temperature performance of Qingchuan rock asphalt is slightly poor,and the amine anti-stripping agent has problems such as insufficient thermal stability and oxidative decomposition.In view of the above problems,this paper is supported by the Shandong Transportation Science and Technology Project “Study on the Modification and Application Technology of Granite in Typical Asphalt Pavement Structure in Weihai Area ”(Project No.: 2017B12),through silane coupling agent and Qingchuan rock asphalt.Blending technology,modification of matrix asphalt,and systematic research on asphalt cement and asphalt mixture,and comparative analysis of slaked lime powder,coupling agent,Weifang coupling agent,Qingchuan rock asphalt,etc.to improve the adhesion of granite asphalt The effect of the road performance of its asphalt mixture is put forward,and the best improvement measures and solutions are proposed.The routine performance test,BBR,DSR,aging performance test and adhesion test of Qingchuan rock asphalt modified asphalt with 0%,3%,5%,7% and 9% dosage were analyzed.The high-temperature properties,low-temperature properties,rheological properties,anti-aging properties and adhesion properties of the aggregates of rock asphalt modified asphalt determine the optimum dosage of Qingchuan rock asphalt.By comparing the performance of the modified modified asphalt with the rock modified asphalt,SBS modified asphalt and silane coupling agent,the modification effect was evaluated.The results show that the high temperature performance of SBS modified asphalt is the best,which is higher than the PG classification of matrix asphalt.The adhesion of composite modified asphalt and granite aggregate is the best.It still meets the requirements after long-term aging,and the low temperature performance is better.Rock-modified asphalt,comprehensive consideration of the water stability of the composite modified asphalt and other road performance.Design AC-10 and AC-16 granite asphalt mixture,through water stability test,water damage sensitivity test,high temperature rutting test,low temperature trabecular bending test,evaluate the improvement of road performance of granite asphalt mixture by different anti-flaking measures effect.The results showed that Weifang coupling agent had the highest residual stability and the highest freeze-thaw splitting strength ratio.Compared with matrix asphalt,silane coupling agent improves the water stability and low temperature crack resistance of granite asphalt mixture,but its water stability after hot oxygen aging is lower than that of composite modified asphalt;Qingchuan rock asphalt shows superior high temperature Anti-rutting ability and aging resistance,but low temperature crack resistance;SBS modified asphalt has outstanding high temperature performance,but water stability is only improved compared with matrix asphalt mixture;Qingchuan rock asphalt and silane coupling agent composite modification Asphalt has outstanding anti-aging and water damage resistance.The superposition effect of the two anti-stripping agents compensates for the defects of poor durability and easy decomposition of silane coupling agent,and compensates for the shortcomings of low-temperature crack resistance of Qingchuan rock asphalt modified asphalt..In order to evaluate the structural performance of the granite asphalt mixture under the coupling of load and environment,the high-temperature accelerated loading test was carried out on the double-layer asphalt mixture composite ruthenium specimen by means of the 1/3scale airbag type acceleration loading system.Based on the rut depth process data with the number of wheel loading,it is found that the creep rate and rut depth of the composite modified asphalt are the smallest,indicating that it has the best high temperature stability performance;the variation law of the rutting of each test scheme is similar to the conventional test law.In the initial compaction phase and the medium-term creep stabilization phase,the rut depth first increases rapidly and then stabilizes at the initial stage of the wheel load.That is,the rut depth increases rapidly and the deformation rate gradually decreases during the initial loading;then enters the creep stabilization phase.The depth of rutting increases slowly with the number of wheel loads,and the deformation rate remains basically unchanged.