Laboratory evaluation of waterborne epoxy bitumen emulsion for pavement preventative maintenance application

摘要

Bitumen emulsions have been widely used for preventive maintenance of pavements in spite of the existing concerns regarding their inadequate mechanical strength and low early strength. Thus, the conventional preventive maintenance techniques using bitumen emulsions are not sufficiently durable in many cases. This study aims to investigate the performance of waterborne epoxy resin modified bitumen emulsions (WEB) as a pavement preventive maintenance material. Florescence tests were performed to characterize the morphology of the bitumen emulsions containing different percentages of waterborne epoxy resin. Pull-off tests were adopted to evaluate the adhesion strength evolution of the modified emulsions with time. Wet track abrasion tests were conducted to optimize the aggregate size for WEB coating layer. Finally, custom-designed rubbing tests were conducted to simulate tyre wearing on pavement surface, and the skid resistances of the WEB coating layer under different wearing conditions were measured and compared with those of a conventional sand fog sealing layer. The laboratory testing results revealed that waterborne epoxy distributed evenly within the bitumen matrix and significantly improved the skid resistance and durability of the pavements maintained with bitumen emulsion coating layer. The optimum dosage of waterborne epoxy and optimum aggregate size range for the WEB coating layer were also identified, which were 50% by weight of bitumen emulsion and 0.45-0.9 mm, respectively. (C) 2018 Elsevier Ltd. All rights reserved.