Study On The Influencing Factors And Mechanism Of Ductility Of Evaporation Residues Of Modified Emulsified Asphalt

Herein,a highly repeatable and reproducible method for obtaining the evaporation residue of emulsified asphalt has been established by using Shuanglong AH-70 modified asphalt as raw material.Moreover,the influence of the structure of emulsifier,the content of emulsifier,the additives and the emulsification process on ductility of evaporation residue of emulsified asphalt are investigated.Finnally,the mechanism on influencing evaporation residue properties were discussed from microscopic perspective by using fluorescence microscopy,infrared spectroscopy and differential scanning calorimetry.By optimization of the technological conditions,the optimized process of obtaining the evaporation residue are as followed:evaporation temperature of phase II is 60?,evaporation time of phase II is 1h,evaporation temperature of phase III is 155?,the finnally evaporated at 165?for 1 min.The comparation of the ductility,the repeatability and reproducibility of the ductility test and the fluorescence micrograph of the traditional evaporation method and the new evaporation method shows that the new evaporation method is more suitable for this study.Different emulsifiers have various effect on the modified asphalt.The results show that the ductility of cationic emulsifier MQK,1831,gemidimidazoline quaternary ammonium salt,MSZ-2 and MSZ-1 on the modified emulsified asphalt is deteriorated gradually.The ductility of the anionic emulsifier sodium dodecyl sulfate,alkali lignin and sodium dodecylbenzene sulfonate on the modified emulsified asphalt is deteriorated gradually.The mix of cationic emulsifier MQK and the nonionic emulsifier OP-10 is better than the single emulsifier MQK,which improves the ductility of the modified emulsified asphalt.The content of emulsifier has a great influence on the ductility of the evaporation residue of modified emulsified asphalt.With the increase of the content of ionic emulsifier,the ductility of the modified emulsified asphalt shows different degrees of attenuation due to different emulsifiers;With the increasing of ionic emulsifier,the ductility of modified emulsified asphalt enhances with a certain degree.The content of emulsifier has a great influence on the ductility of the evaporation residue of modified emulsified asphalt.With the increasing of ionic emulsifier,the ductility of the modified emulsified asphalt shows different degrees of attenuation due to different emulsifiers;With the increasing of ionic emulsifier,the ductility of modified emulsified asphalt enhances with a certain degree.The addition of HEC,CMC and CaCl₂ reduced the ductility of the evaporation residue of the modified emulsified asphalt.With the increasing of the content,the ductility of the evaporation residue of modified emulsified asphalt showes a decreasing trend.The attenuation of the evaporation residue of modified emulsified asphalt by CMC,HEC and CaCl₂ increase in turn.In addition,the emulsification process conditions are also important factors on influencing the ductility of the evaporation residues of emulsified asphalt.As the temperature of the modified asphalt increases,the ductility of the evaporation residue is gradually decreased,and the degree of attenuation of the evaporation residue is increased.At different solution temperature,the ductility of the evaporation residue of the modified emulsified asphalt is not changed obviously.Different emulsifiers have different the optimum pH value.2 is the optimum pH of cationic emulsifiers,and 9 is the optimum pH of anionic emulsifiers.Microscopic characterization results show that the change of the ductility of the modified emulsified asphalt is due to the aggregation of un-crosslinked SBS particles in the evaporation residue and the inhomogeneously distributed emulsifier.The rules of microscopic characterization are consistent with macroscopic phenomena.