Preparation Of Asphalt Emulsifier For Micro-surfacing And Studies On Their Performance

As the focus of transportation shifts from construction to maintenance in China,microsurfacing,a preventive maintenance method,has been widely used in the road maintenance due to its excel ent performance.The emulsifier for micro-surfacing must be slow cracking and fast setting type,and the relevant performance of the emulsified asphalt and asphalt mixt ure prepared with it must meet the application requirements at the micro-surfacing.However,the current emulsifiers used in micro-surfacing have some problems,such as high price,complicated preparation process,large difference in application effect to different asphalt or different aggregates,and poor effect of slow cracking and quick setting,and so on.Therefore,it is important to engineering for developing asphalt emulsifiers with outstanding comprehensive performance and low cost.Fatty acids and polyethylene polyamines with wide sources,low cost,and no environmental pollution were selected as raw materials in this thesis.Amide emulsifiers and imidazoline cationic emulsifiers were synthesized,and the related synthesis process and emulsification process of emulsifiers were investigated systemically.The emulsifiers with the best performance were selected from the two types of emulsifiers,and non-ionic emulsifier OP-10 was used in combination to further improve the comprehensive performance of the emulsifiers and reduce the cost of the emulsifiers.Finally,two compound emulsifiers were applied to the micro-surfacing,and the road performance of the mixture at the micro-surfa c ing was tested.In the research process of a series of amide and imidazoline emulsifiers,the synthesis and emulsification process of emulsifiers were studied using lauric acid and diethylenetriamine as raw materials.The best synthesis process of amide emulsifier was: 150℃ for reaction temperature,6 h for reaction time,and 1:1.2 molar ratio for acid and amine.The best emulsification process was: 1.5% for emulsifier content,4 min for colloid mill shear time,and 60℃ for soap liquid temperature.The best cyclization conditions for imidazoline emulsifiers were: 220℃ for cyclization temperature,and 6 h for cyclization time.The best emulsifica t io n process was: 2% for emulsifier content,4 min for colloid mill shear time,and 60℃ for soap liquid temperature.The optimal compounding ratio of both cationic emulsifiers and nonionic emulsifier OP-10 was 6:4,and the modified emulsified asphalt prepared at this ratio has excel ent performance.The modified emulsified asphalt prepared by the two compound emulsifiers was subjected to a slurry mixture test to explore the optimal oil-rock ratio and test the performance of the mixture at the micro-surfacing.It was found that the abrasion resistance,water resistance,rutting resistance,anti-slip performance and impermeability of the mixture of the two modified emulsified asphalts at the micro-surfacing meet the requirements of the microsurfacing.