Studies on the temperature performance of SBR modified asphalt emulsion

Abstract

Styrene butadiene rubber (SBR) modified asphalt emulsions were prepared by means of SBR latex adding to aqueous solution, and it is an energy-saving, ecologically safe material because it does not need any heating processes creating gas emission and fire hazard during its use. The objective of this work was to analyze the temperature performance of SBR modified asphalt emulsions for enhancing the pavements properties. According to penetration index (PI) of emulsion residues, it was found that the temperature susceptivity of asphalt became lower by SBR modification, which was more favorable for practical application. And PI firstly increased and then decreased with the SBR content increasing, which was attributed to SBR content and whether it could disperse uniformly in emulsion residue. Furthermore, the increase of equivalent softening point (T <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">800</inf> ) of asphalt by SBR modification indicated that the thermal stability and the heat resistance of asphalt were significantly enhanced. Third, 5 °C ductility and equivalent brittle point (T <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.2</inf> ) was used for characterizing low-temperature property of modified asphalt. Compared to unmodified asphalt emulsion, the increase of low temperature ductility and decrease of T <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.2</inf> of modified asphalt emulsion demonstrated that anti-cracking performance was improved considerably. And the change of low-temperature ductility was related to the cohesion inside the emulsion residue and whether SBR could distribute uniformly in it. As a consequence, the optimum SBR latex content was determined as 4.0% to 5.0% to emulsion. In this concentration, the temperature performance of SBR modified asphalt emulsions was excellent and this favorable for application.