Physical and Rheological Properties of High-Float Emulsified Asphalt Residues for Chip Seal Applications

Asphalt surface treatments using asphalt emulsions are widely used in the road industry for pavement preservation, with chip seal being particularly popular due to its low initial cost and ease of construction. High float asphalt emulsions (HFAE) have been developed as an alternative to traditional asphalt emulsions to mitigate common issues such as bleeding, draining, and aggregate chip loss associated with chip seals. Unlike traditional asphalt, residue from HFAE exhibits unique characteristics, traditionally assessed through float tests. This study investigates the behavior of HF emulsified asphalt residues using alternative physical and rheological tests. Visual flow and drain down experiments were conducted to evaluate asphalt's resistance to flow and draining, while a stress sweep test measured the viscosity of HF emulsified asphalt residue. The results showed that HFAE residue demonstrated significant resistance to flow and drain down. Rheological evaluation via the stress sweep test revealed that HFAE residue exhibits a yield stress nature not present in the original asphalt, contributing to its high float characteristics. Understanding how yield stress varies with the type or percentage of emulsifier used can provide valuable insights, enabling researchers to select appropriate HF emulsifiers based on specific field requirements.