Preparation And Performance Evaluation Of Fully Recycled Asphalt Mixture Based On The Characteristics Of Emulsified Asphalt Mastic

The recycling technology of asphalt mixture has always been a hot spot and development direction in the industry.At present,it mostly exists in the form of hot regeneration and cold regeneration.The former has the problems of low RAP consumption and low environmental benefit,while the latter has the key technical problems such as slow intensity formation and low application level.With the development and intersection of new technological concepts,the technology of emulsified asphalt warm mix fully recycled asphalt mixture has emerged,representing a more environmentally friendly and excellent direction for asphalt mixture recycling technology.Based on this development situation,this thesis combined emulsified asphalt warm mixing technology,high modulus asphalt mixture design technical features.Emulsified asphalt was selected as binder.Based on the characteristics of RAP particles,HMAC design concept was used for reference(high oil-stone ratio,c continuous gradation,low porosity,etc.).To explore the properties of emulsified asphalt mastic.Provide a new idea and method for the design and preparation of fully recycled asphalt mixtures by combining warm mixing methods.The comprehensive road performance of emulsified asphalt warm mixed fully recycled asphalt mixture was systematically evaluated,and engineering practice and verification were conducted.The research conclusions are described as follows.(1)In order to achieve RAP100% content of warm mix regeneration.Based on RRS equation,this study explored the particle variation characteristics of RAP from the two indexes of aggregate characteristic size and uniformity.And further study and analyze the characteristics of recycling asphalt pavement materials by extracting and refining the RAP provided by the project.The results show that asphalt has obvious aging problem after many years of service,and the problem of mineral refinement is serious,and there are difficulties in the gradation design of conventional mixture.Through the design concept of high modulus asphalt mixture,it can solve the problems of asphalt aging hardening and high content of fine powder.(2)To explore the feasibility analysis of full regeneration based on mastic design.Through the conventional test and rheological test of various types of emulsified asphalt mastic,the characteristic law of the change of properties with powder binder ratio was established,and the technical index of high modulus hard asphalt was established.The results show that the emulsified asphalt mastic can harden the binder when the powder-to-rubber ratio is above 1.2.(3)Through the design and simulation of the performance change law of emulsified asphalt in the short-term aging process,the performance recovery characteristics of emulsified asphalt are explored.The test results show that G*,n,and ∣n∣ in DSR40℃ temperature scan have good correlation with test temperature and test duration.The relationship between the recovery of emulsified asphalt properties and temperature and time can be established.In laboratory research and engineering practice,the application temperature of emulsified asphalt can be increased to meet the bond characteristics of binder,and the full regeneration can be achieved under the condition of warm mixing,so as to ensure the early road strength.(4)In order to meet the requirements of low porosity,high oil-stone ratio and continuous gradation,the whole reclaimed asphalt mixture was prepared by using a single powder binder ratio determined.Drawing on the current evaluation methods and systems of relevant regulations,explore and evaluate the regeneration effect of various types of 100% RAP content warm mixed fully recycled asphalt mixtures.The results show that the properties of high and low temperature,fatigue and water stability of the recycled mixture meet the road requirements.The feasibility of using the characteristics of emulsified asphalt mastic to guide the design concept of full regeneration was verified.(5)In order to further verify the design concept of guiding full regeneration based on the characteristics of emulsified asphalt mastic.The construction of Jiuqu Huahai Tourist Road and Yamahu X008 test road were carried out,and the indoor tests were carried out to verify the results,the results show that the test road performance has good road performance,based on the characteristics of emulsified asphalt mastic recycling design method is feasible.