Research On Design Method Of AC-13 Cold-mixed Cold-laid Emulsified Asphalt Mixture

The cold-mixed cold-paved emulsified asphalt mixture is mixed under normal temperature conditions,which has the characteristics of convenient construction,energy saving,and construction in winter.At present,the design method of asphalt mixture in China is mainly for hot-mix asphalt mixture and cold-recycled asphalt mixture.The specific mix design method of cold-mixed and cold-paved emulsified asphalt mixture has not been determined at home and abroad.Therefore,the mixing ratio design method of cold-mixed and cold-paved emulsified asphalt mixture is studied to determine in advance what kind of performance the mineral gradation used will provide and whether the mineral gradation is suitable and how to adjust it.It is of great significance to improve the selection efficiency of gradation and the performance of cold-mixed and cold-paved emulsified asphalt mixture.In view of this,on the basis of previous researches and the fractal theory,this paper takes AC-13 type cold mixed cold paved emulsified asphalt mixture as the main body,established the road performance prediction model of cold mixed cold paved emulsified asphalt mixture by calculation software.Combining the characteristics of climate,transportation and materials in the Liaoning area of China,an optimization method for the mix ratio design of AC-13 cold mixed cold paved emulsified asphalt mixture based on road performance is proposed.The main content and results are as follows:(1)Analyze the strength forming mechanism of cold-mixed cold-paved emulsified asphalt mixture,and design multiple sets of suspension dense AC-13 emulsified asphalt mixture in combination with the structure type of asphalt mixture.Analyze the influencing factors of the test,including the mixing method,compaction method and health maintenance method of emulsified asphalt mixture,and determine the optimal moisture content and the optimal emulsion dosage.(2)Combined with the fractal theory,the fractal characteristics of the aggregate of asphalt mixture were analyzed,and the distribution function of aggregate passing rate,the fractal dimension of volume and the calculation formula of fractal dimension were derived.Calculate the different fractal dimensions of the design of multiple sets of cold-mixed and cold-paved emulsified asphalt mixtures.(3)Road performance tests were conducted on cold-mixed and cold-paved emulsified asphalt mixtures for high temperature stability,low temperature crack resistance,and water stability,respectively.With the help of calculation software,the ternary primary fractal prediction model of each road performance index and fractal dimension(aggregate fractal dimension D,coarse aggregate fractal dimension Dc,fine aggregate fractal dimension D_f),two The primary fractal prediction model and the secondary fractal prediction model.After comparison and analysis,the optimal road performance prediction model is recommended and applied to the optimal design of the mix ratio of cold-paved and cold-laid emulsified asphalt mixture.(4)Determine the range of the gradation fractal dimension of the cold-mixed cold-paved emulsified asphalt mixture that meets the technical specifications for road performance.Take the fractal dimension D to derive the gradation particle size passing rate,determine the gradation,and use the road performance prediction model to carry out road performance inspection to obtain an excellent grade that meets the road performance requirements.The gradation selection and design in the mix ratio design of cold mixed cold laid emulsified asphalt mixture were optimized,and then the mix design method of AC-13 cold mixed cold laid emulsified asphalt mixture based on road performance was proposed.Provide a reference for engineering applications,has a certain practical application value and significance.