Effect Of Cement On The Performance Of Central Plant Cold Recycling Mixture Using Emulsified Asphalt

With the rapid development of China's highway industry,the early construction of asphalt pavement began to enter the stage of major and medium repair,which will produce a large number of waste asphalt pavement materials.The mixed cold recycling technology of emulsified asphalt plant can make full use of waste asphalt pavement materials,save energy,reduce the exploitation of mountain bodies,protect the environment and meet the national development cycle economic and sustainable development strategies.In this study,the effects of cement on emulsified asphalt cold recycling materials were analyzed from the aspects of raw material composition,mix ratio design,macroscopic road performance and micro mechanism of cold recycling technology of emulsified asphalt.In order to study the mechanism of cement emulsified asphalt cold regeneration material performance and determine the best range of the amount of cement,the different dosage of P.O 32.5 cement and K.O 32.5(0%?5%)of the emulsified asphalt cold regeneration material of microstructure observation and analysis of chemical composition,and mechanical testing of emulsified asphalt mixture performance.The recycled mixture of emulsification asphalt cold uniaxial penetration test,indirect tensile test and freeze-thaw splitting test and so on,from the high temperature stability,low temperature crack resistance and water damage resistance and verify the emulsification asphalt cold recycled mixture of macro pavement performance.The research showed that the emulsified asphalt cold recycled mixture high temperature stability and water stability increased with the increase of cement content,low temperature performance with the increase of cement content changed properties increased first and then decreased.When the cement content is in the range of 1%to 2%,the performance of emulsified asphalt cold recycled mixture is the best.Through the scanning electron microscope and the electronic spectrum analysis of the emulsified asphalt plant cold recycling rubber mortar,the results of macroscopic road performance test are verified.The results showed that the fibrous crystals observed by SEM were indeed the hydration products generated by hydration reaction of cement and mixture,and the cement paste formed by hydration products of cement and asphalt formed three-dimensional mesh structure in space.When the cement content is 1%to 2%,the hydration products of cement do not form a clear and angular fiber crystal.The fiber is short,and the fiber is short(<10?m),most of which are distributed at 5?m.When the cement content is more than 3%,the crystal after hydration is dense and needle like,and the fiber is longer(some cement hydration product crystal length>20?m).These cement hydration products have a "reinforcement" effect on the cold recycled mixture of emulsified asphalt and can improve the early strength of the cold recycled mixture of emulsified bitumen.