In order to study the influence of Ultrafine inorganic modifiers such as cement and hydrated lime on the performance of asphalt and asphalt mixture.In this paper,2.5%,5% and 7.5% of cement powder and hydrated lime powder are used to configure Ultrafine inorganic modified asphalt.Through the experiments of penetration,ductility,softening point,DSR,etc.of modified asphalt,the effects of Ultrafine inorganics such as cement and hydrated lime on the basic index,aging performance and high temperature rheological properties of asphalt are analyzed;Ultrafine inorganic modified asphalt Formed AC-20 C asphalt mixture,and analyzed the high temperature,low temperature performance and water of asphalt mixture by the amount of cement and hydrated lime in the asphalt through water immersion Marshall test,freeze-thaw split test,high temperature rutting test,and low temperature bending test The impact of road performance such as stability.Through the multiple freeze-thaw cycles test,long-term aging test and indirect tensile fatigue test of asphalt mixture,the influence of inorganic powder modifiers such as cement and hydrated lime on the durability of asphalt mixture was analyzed.And through the test results,the modification mechanism of inorganic fine powder modifier to asphalt and asphalt mixture was analyzed.Asphalt test results show that after adding Ultrafine inorganic modifiers such as cement and hydrated lime to the base asphalt,the penetration and ductility of asphalt decrease,and the softening point increases,and the addition of Ultrafine inorganic modifiers makes the penetration of asphalt before and after aging As the ratio and ductility ratio increase,the difference in softening point decreases,the anti-aging ability of asphalt is improved,and the improvement effect is positively correlated with the amount.As cement and hydrated lime increase,the phase angle of asphalt decreases,the complex shear modulus and rutting factor increase,and the high-temperature rutting resistance of asphalt improves.When the amount of cement reaches 2.5% or the amount of hydrated lime reaches 7.5%,the PG high-temperature grade of modified asphalt can be increased by one level.Asphalt mixture road performance test results show that,after the base asphalt is mixed with Ultrafine inorganic modifiers such as cement and hydrated lime,the water stability of the asphalt mixture is proportional to the amount of cement modified asphalt at the same amount.The strength of the mixture is higher than that of the hydrated lime group,and the residual stability in water immersion and the splitting strength ratio of the freeze-thaw test have little change compared with the matrix asphalt mixture.Ultrafine inorganic modifiers such as cement and hydrated lime can improve the hightemperature stability of asphalt mixtures,and the lifting effect is proportional to the amount.The dynamic stability of cement-modified asphalt mixtures at the same amount is higher than hydrated lime.The low-temperature bending test results show that the addition of cement,hydrated lime and other inorganic micro-powder modifiers to the matrix asphalt is detrimental to the low-temperature performance of the asphalt mixture.At the same dosage,the low-temperature performance of the cement-modified asphalt mixture is lower than that of the hydrated lime group.Through the road performance test,the performance of cement and hydrated lime modified asphalt mixture is compared,the advantages and disadvantages of the conventional dry blending method and the mortar method used in this article,comprehensive consideration of the mortar method for the modified mixture The road performance modification effect is better.The test results of the durability of asphalt mixtures show that by adding 5% cement or hydrated lime powder to the matrix asphalt,the ability of the asphalt mixture to resist long-term water loss is significantly improved,and the modification effect of the added cement is better than hydrated lime;The agent can also significantly improve the water stability of the asphalt mixture after aging,and improve the low-temperature ultimate bending strain ratio before and after aging to a certain extent;adding 5% cement fine powder to the matrix asphalt,the asphalt mixture under stress mode Fatigue life has a certain effect.The mechanism analysis results of Ultrafine inorganic modified asphalt and asphalt mixture show that the fineness,particle morphology and chemical properties of Ultrafine inorganic will affect the modification effect.Comprehensive test results of Ultrafine inorganic modified asphalt and asphalt mixture,Ultrafine inorganic modifiers such as cement and hydrated lime can better improve the road performance and durability of asphalt and asphalt mixture,which is beneficial to prolong the service life of pavement. |