Study On Comprehensive Optimization Evaluation Of Warm Mix Asphalt Technology

Warm mix asphalt technology has developed rapidly,especially in the United States,Japan,Germany,Italy and other countries,the scope of application is gradually expanding.The introduction of warm mix asphalt technology in China has carried out a great deal of research work over the past ten years,but the extensive application is still limited,there are some problems in the research of technology,and there is a lack of complete evaluation system of warm mix asphalt technology.In this paper,the indexes and methods of performance evaluation of warm mix agent and the comprehensive evaluation system of warm mix asphalt technology are put forward,which provides the basis for the development and application of new warm mix asphalt technology.By analyzing the cooling mechanism and mixture performance of warm mix agent,the performance of warm mix agent was evaluated from four aspects of viscosity temperature characteristics,compaction characteristics,water stability and high temperature stability.Materials such as A,C,D,water warm mixing agent,EC120 and Aspha-min were selected,and the technical properties of warm mix asphalt and mixture were studied.A set of performance evaluation system of warm mix agent was put forward,in which the evaluation indexes and standards.Based on this evaluation standard,the research and application of 1⁵ warm mix agent and EC120 warm mix agent with excellent performance were studied.The results showed that the performance of No.2 warm mix agent is better than the other,but the warm mix asphalt freeze-thaw splitting strength ratio is low in comparison to the EC120,the warm mix agent No.1 and No.5 have great influence on the air voids and freeze-thaw splitting strength ratio of the mixture.In this paper,a comprehensive optimization evaluation system is established,according to the economic benefits,environmental benefits,road performance and other factors of warm mix asphalt technology.A series of indexes are put forward,including the comprehensive performance of warm mix asphalt,the cost of mixing agent,the ratio of cost to benefit,the range of CO₂ emission reduction and the amount of pollution emission reduction.Based on the former research,using principal component analysis method to optimize the Sasobit,Evotherm,Aspha-min three kinds of technology according to the established evaluation indicators,and analyzed the optimization method of applicability and existing problems.The research shows that the technology of Sasobit warm mix asphalt is optimum,followed by Evotherm warm mixing technology,and finally Aspha-min warm mixing technology.The optimization method of the warm mix asphalt technology is flexible,and the evaluation indexes can be adjusted dynamically according to the performance requirements of different warm mixing agents,so as to provide important reference basis for the construction production.