Impacts Of Aggregate Characteristics On Modified Asphalt Emulsion And Micro-surfacing Mixture Properties

With the development of transportation, the construction of China’s highway networktends to increasingly complete. The maintenance and disease prevention of highway asphaltpavement attract widely attention. As a good preventive maintenance measurement, micro-surfacing technology has been widely used at home and abroad.Firstly, this paper analyzed the emulsification mechanism, storage stability mechanismand breaking mechanism of the modified asphalt emulsion. Through laboratory tests, theeffects of matrix bitumen, emulsifier dosage, modifiers dosage, shearing time and stabilizingagent on the emulsification effect, technical parameters and storage stability had been studied.Secondly, the main chemical components and zeta potentials of the limestone, basalt andgranite had been analyzed by X-fluorescence spectrometry analysis and Electro osmosisapparatus. The results shows that the main chemical composition of limestone is calciumcarbonate, and silicon dioxide contents of the basalt and granite aggregate are respectively55.851%and86.74%. In the water environment, the limestone aggregate surface containscertain positive charge, while basalt and granite aggregate surfaces contain negative charge,and the three zeta potential of the aggregates are respectively+11.32mV,-9.87mV and-29.75mV. According to the electric charge theory and chemical reaction, the changes inviscosity of the fine aggregate mortar, which made by the three kinds of the aggregates, wereanalyzed.Thirdly, the viscosity variation of fine aggregate mortar was analyzed byGompertz model formula. And the values calculated by Gompertz model formula werecompared with the measured values, the results shows that the difference between themeasured values and the calculated values is less than20%, which proves that theGompertz model Method is a reliable method to predict the viscosity variation of fineaggregate mortar. Then according to the Gompertz model formula, a evaluating indicator （t）was proposed to judge the complete emulsification of the modified asphalt emulsion,the variation of the evaluating indicator （t）and its influence by the aggregate’s characteristics were analyzed.Finally, we researched on the technical parameters of the micro-surfacing mixture, whichmade by the three kinds of aggregates; and analyzed the differences of the mixable time,cohesive strength, wet track abrasion and sand adhesion among the three kinds ofmicro-surfacing mixtures.