Preparation and performance evaluation of emulsified asphalt with rejuvenator and latex for pavement seal coat

Abstract

With the rapid growth of transportation, the requirement of emulsified asphalt (EA) for seal coat changed from singular performance to comprehensive performance. To increase the function of EA, the rejuvenator was added to endow the possibility to rehabilitate deteriorated asphalt pavement, and the latex was included to guarantee the performance of EA. The study aims at investigating the effect of adding rejuvenator and latex in EA. Therefore, EA containing rejuvenator (three content levels) and latex for pavement seal coat was prepared and its performance was evaluated. Based on the investigation of the effect of rejuvenator on its technical performance, an appropriate formula of modified EA with moderate viscosity and excellent performance was selected. Then, the high- and low-temperature and fatigue resistance performance of the evaporation residue of the appropriate modified EA as well as a SBS-modified asphalt and base asphalt binder were evaluated by dynamic shear rheometer and bending beam rheometer. Based on the results, it was found that the addition of rejuvenator and latex had significantly increased the saybolt viscosity, which was desirable for adhesion of EA. With the rejuvenator content increased from 2% to 5%, the saybolt viscosity of modified EA gradually decreased since the rejuvenator reduced the internal friction. The types of emulsifier had no significant effect on this evolution. The storage stability of EA improved noticeably with the addition of rejuvenator and latex (concentration difference decreased from 21.3% to 85.1%). The types of emulsifier would affect the variation of storage stability with increasing rejuvenator content. All the modified EA had higher solid content, penetration, and elastic recovery rate than the normal EA. The penetrations of modified EA were more susceptible to the content of rejuvenator, whereas the solid contents and elastic recovery ratios were almost independent of the rejuvenator content. Results also reveal that among the modified EA evaporation residue, SBS-modified asphalt and base asphalt binder, the modified EA evaporation residue had the longest fatigue life and the comparable low-temperature performance with SBS-modified asphalt. However, it had the poorest high-temperature performance for all the three binders. Therefore, it can be said that the modified EA with rejuvenator and latex has feasibility and potential, which will provide theoretical foreshadowing for application of the modified EA on deteriorated asphalt pavement.