A comprehensive study on adhesion between modified bituminous binders and mineral aggregates

Abstract The lifetime cost and environmental footprint of asphalt pavements hugely depend on their durability. It is widely accepted that water action plays a crucial role in the deterioration of hot mix asphalt concretes. Researchers seek solutions for promoting adhesion between bituminous binders and aggregate to avoid debonding (stripping) due to the presence of water and mechanical loading. In this research study, five different adhesion promoters were studied at multiple scales. The impacts on bituminous binders, their interactions with water and aggregates, and macroscopic properties of a selected type of asphalt concrete were assessed using both custom and standardized experimental test methods. The study revealed that the performance of additives cannot be assessed based on the results of a single test. A correlation was found between bituminous binder adhesion to aggregates, fracture-mechanical properties of asphalt concretes, and their susceptibility to deterioration in mechanical properties. The results indicate that silane-based adhesion promoter holds the biggest promise for increasing the resistance to stripping in asphalt concrete pavements.