Cement Asphalt Mortar Sbs Modified Asphalt Emulsion Stability Study

China railway track system I (CRTS I) is one of the main type of the slab ballastless track structure in Chinese High-speed Railway. Cement and emulsified asphalt mortar cushion which provide functions on supporting, levelling, adsorbing and reducing vibrations is the key material of CRTS I. The performance of cement and emulsified asphalt mortar cushion will directly affect the durability of track structure and the security of trains. Therefore, the performance and quality of cement and emulsified asphalt mortar is the key to success or failure of the slab ballastless track structure application, and the quality and stability of emulsified asphalt is the key to the construction quality and performance of cement and emulsified asphalt mortar. So, it is quite necessary to study the main factors affecting the stability.This paper studies the effect of emulsion system, storage and transportation conditions, the production process on the stability of SBS modified asphalt emulsion.Results show that:(1) the type and content of emulsifier, stabilizer type and content, thickener content, compound emulsifier, modified bitumen and pH value of the soap have a great impact on the storage stability of the SBS modified asphalt emulsion;(2) The stability of emulsified asphalt becomes worse with the extension of storage time; When the samples are stored under different circumstances, but the storage time is fixed, the higher the storage temperature, the worse the stability of emulsified asphalt is; under the same storage time, the stability of samples stored in the car are worse than those stored in the laboratory; There is no difference between the stability of samples stored in aluminum containers and those stored in plastic containers, but stability of the sample which stored in iron containers are worse than those stored in aluminum containers and plastic containers.(3) When the colloid mill worked at a high speed, the particle size of SBS modified asphalt is smaller, and its distribution is more uniform, the stability of asphalt emulsion is better; A higher asphalt temperature is good to get a stable SBS modified asphalt emulsion; stability of SBS modified asphalt emulsion storage with the soap temperature, showing a trend first increse and then decreased; It is good to the stability of SBS modified asphalt emulsion to added thickener, stabilizer to the soap before producting.