Preparation and performance of an asphalt pavement sealant with waterborne epoxy resin

Abstract

• The design content of WER in SBS modified emulsified sealant was identified. • Effect of WER on the adhesive strength of WER-SBS-EA was investigated. • Ultraviolet aging characteristics of WER-SBS-EA were studied at different radiation times. At present, crack sealing is a widely accepted routine preventative maintenance practice of asphalt pavements. Successful crack sealing is perceived to be of the primary importance by maintenance engineer because if not properly exercised, excessive aging, extended cracking, and high temperature flow deformation of pavements will be resulted. In this study, the waterborne epoxy resin (WER) and styrene butadiene styrene (SBS) composite modified emulsified asphalt sealant (WER-SBS-EA), was prepared. The optimum contents design of modified emulsified asphalt (SBS-EA) was identified by the shear strength test. Then, the properties of the WER-SBS-EA were investigated by contact angle, pull-off, and indoor accelerated ultraviolet (UV) aging tests. The results showed that the shear strength of the WER-SBS-EA was increased by WER, and the optimum proportioning of the WER: SBS-EA was 2:3. The WER-SBS-EA, with a contact angle greater than 90°, i.e. was hydrophobic. The surface energy and work of adhesion of the WER-SBS-EA were higher than those of the SBS-EA, which means that the WER-SBS-EA has good bonding strength. As the temperature and immersion time increased, the bonding strength of the WER-SBS-EA was decreased but still higher than that of the original SBS-EA. In addition, the shear strength of the WER-SBS-EA after aging for 16 days is still 44.4 % higher than that of the unaged SBS-EA; hereby the presence of WER in the asphalt sealant can help counteract the stiffening effect resulting from oxidative hardening. Therefore, the WER-SBS-EA can be used for preventive maintenance and is of great significance for extending the service life of the asphalt pavement.