The Study On Preparation And Application Of Modified Asphalt Emulsion By Cement Asphalt Mortar In Plateau-cold Region

Ballastless slab track is a type of the most important track forms in passenger line, with manifold advantages of fixes, facilitates the construction and long using life, which have been successfully used in warm and cold region, but colder environmental conditions. Cement asphalt mortar (more often knows as CA mortar) is the key material of ballatstless slab track, influencing its durability and safety, and it is important for the preparation of the CA mortar to track slab structure. Therefore, it is very important to study on the CA mortar of ballastless slab track in plateau-cold region.The paper undertook a systematic study on asphalt emulsion and mix proportions of CA mortal, combined the property requirements of CA mortar in ballastless slab track.The main work and results were briefly given as follows:1. Using the optimal SBS-modified asphalt as based asphalt, self-preparation compound emulsifier, SBS modified asphalt emulsion were prepared. Factors affected the preparation of SBS modified asphalt emulsion were investigated. Results showed that SBS modified asphalt could well be emulsified by compound emulsifier, which is under the ratio 90:8:2 of cation, non-inonic and anonic.Under the conditions of an emulsion pH value of 2~3,an oil temperature of 160~165℃,a warder temperature of 60~65℃,a emulsified time of 3minutes,an oil to water mass ratio of 60:40 and a compound emulsifier dosage of 2.0%,the qualities of the obtained products is good.2. Using the SBS-modified asphalt as based asphalt, SBR latex as compound modifier, SBR-SBS modified asphalt emulsion were prepared, Meanwhile five types of latexes were selected. Factors affected the preparation of compound modified asphalt emulsion were investigated and the storage stability of the prepared compound modified asphalt emulsion were studied as well. Results showed that the effect of the type and dosage of SBR latex on the performance of the compound emulsion is great. Polymerization temperature, low bound styrene content of cationic SBR latex D have a good compatibility with SBS-modified asphalt emulsion. Under the conditions of an emulsion pH value of 2,an oil temperature of 160℃,a water temperature of 65℃,a emulsified time of 3minutes,an oil to water mass ratio of 60:40,a SBR latex dosage of 9%,a compound emulsifier dosage of 2.0%,an ammonium chloride dosage of 0.15% and a PU dosage of 0.25%,the qualities of the obtained products could meet the standard,whose evaporation residues performance is better than SBS modified asphalt, especially the ductility of low temperature3. The CA mortar used in plateau-cold region was studied in the basis of CA mortar in cold region. Results showed that the CA mortar prepared under the conditions of a asphalt to cement mass ratio of 0.65~0.70, a wood fiber to cement ratio of 0.015~0.025, a water to cement ratio of 0.65~0.70, a sand to cement ratio of 1.8~2.0, have good low temperature performance, and with a low elastic modulus and high compressive strength, which could meet the requirements of ballastless slab track in plateau-cold area.