Abstract: Using Karamay 90# heavy duty road asphalt as base asphalt, SBR latex as modifier, SBR modified emulsified asphalt were prepared, meanwhile three types of emulsifiers and stabilizers were selected respectively. Factors affected the preparation of SBR modified emulsified asphalt were investigated and the storage stability of the prepared modified emulsified asphalt were studied as well. Results showed that processing emulsification and modification simultaneously, under the conditions of an emulsion pH value of 5-6, an asphalt temperature of 120℃, a water temperature of 60℃, an oil to water mass ratio of 1, a B emulsifier dosage of 1.0%, a SBR dosage of 3% (based on asphalt) and an ammonium chloride dosage of 0.2%, the qualities of the obtained product could meet the specifications of JTG F40-2004 issued by China Ministry of Communication. Further more, the dosage of emulsifier could be reduced about 30% if composite emulsifier was adopted.

Key words: SBR latex, emulsified asphalt, storage stability, composite emulsifier, modification