| In the application process of emulsified asphalt,asphalt particles are prone to sedimentation,uneven coated with aggregate,poor adhesion performance and other problems,which will affect the pavement performance of emulsified asphalt.These problems are caused by the poor performance of key technologies such as storage stability,wetting and film forming of emulsified asphalt itself,and the unclear influence mechanism.As a result,in order to understand the development of emulsified asphalt technical performance and related mechanisms,control the technical performance of emulsified asphalt,and ensure and improve the quality of emulsified asphalt-based materials.In this paper,the preparation technology of emulsified asphalt,storage stability prediction model,film forming performance,wettability and adhesion performance to aggregate are studied.The preparation technology of emulsified asphalt was systematically studied,and the effects of emulsifier variety and dosage,stabilizer variety and dosage,stabilizer addition technology,and basic preparation technology parameters on the basic technical performance of emulsified asphalt were investigated,and the method of controlling the particle size distribution of emulsified asphalt is mastered and the best preparation technology of emulsified asphalt is determined.The influence of emulsified asphalt preparation technology on emulsification effect and storage stability was evaluated by grey relational theory.The results showed that p H value and matrix asphalt temperature had the greatest influence;based on the Stokes sedimentation formula,the relation of particle size and storage stability were established.The storage stability prediction model based on the viscosity and particle size of the emulsified asphalt has been established to realize the rapid prediction of the storage stability of the emulsified asphalt.The influence mechanism of emulsified asphalt’s wettability was studied through contact angle test,and the influence degree of various factors on the wettability was evaluated based on the grey correlation theory.The results show that the order of the wettability of the three emulsifiers is KZW>LF>LH,and the order of the wettability of the emulsified asphalt to different aggregates is limestone>basalt>granite>matrix asphalt>aged asphalt.In addition,the wettability of emulsified asphalt to aggregate increases with the increase of emulsifier content and aggregate roughness;adding wetting agent helps to improve the wetting performance of emulsified asphalt;according to the gray correlation theory,the dosage of matrix asphalt and emulsifier has the greatest influence on the wetting ability of emulsified asphalt.Based on the theory of dry film formation,the calculation method of the maximum accumulation rate of emulsified asphalt particles(φ_m)is proposed.Based on the rheological test,the change process of emulsified asphalt dry film formation performance is studied,and the relationship betweenφ_m value of emulsified asphalt and the complex modulus of evaporation film formation,the ratio of complex modulus of evaporation film formation and ideal film formation is clarified.The results show that the complex modulus of the emulsified asphalt film formation increases with the increase ofφ_m,and the ratio of the complex modulus of the evaporation film formation to the ideal film formation increases with the increase ofφ_m.The influence mechanism of the adhesion performance of emulsified asphalt was studied through pull-out tests,and the relationship between emulsified asphaltφ_m and adhesion performance,and the complex modulus of emulsified asphalt film and adhesion performance was clarified.The results show that the order of the adhesion performance of the three emulsifier emulsified asphalt to aggregate is KZW>LH>LF,and with the increase of emulsifier content and matrix asphalt content,the adhesion performance of emulsified asphalt to aggregate gradually increases;The order of adhesion performance of emulsified asphalt to different aggregate is limestone>basalt>granite;the adhesion performance of emulsified asphalt to aggregate increases with the increase ofφ_m,and the increase of complex modulus.To sum up:this paper systematically studied the preparation technology of emulsified asphalt,studied the key technical performance impact mechanism of emulsified asphalt,and established an storage stability prediction model,established an emulsified asphalt quality evaluation system based onφ_m,which is beneficial to guarantee and improve the construction quality of emulsified asphalt mixtures,realize the further application of emulsified asphalt. |
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