A review of the application of crosslinking additives in asphalt binder modification for rheological changes and storage stability

Polymers, rubber, carbon black, nanomaterials, and other substances are frequently used for producing modified asphalt binders, which strengthen their ability to withstand fluctuating temperatures and growing vehicular loads. In order to achieve the intended performance, crosslinking agents/additives are frequently utilized to enhance the compatibility of various modifiers with the asphalt binder. This literature review paper provides a discussion on the use of different crosslinking agents, such as sulfur, dithiodimorpholine (DTDM), tetraethyl thiuram disulfide (TETDS), polyphosphoric acid (PPA), trans-polyoctenamer rubber (TOR), and peroxide, in the formulation of modified asphalt binder with different polymers, such as styrene-butadiene-styrene (SBS), ethylene vinyl acetate (EVA), and polyethylene (PE), as well as different rubber modifiers, such as styrene-butadiene rubber (SBR), crumb rubber (CR), and ethylene-propylene-diene-monomer (EPDM) rubber. The fundamental concepts of the chemistry of modified asphalt binder are covered first, and then various crosslinking additives/agents and their effects on the storage stability/compatibility and chemical and rheological properties of modified asphalt binder are reviewed. The environmental effects of using these crosslinking agents with modified asphalt binders are also covered in the present work. The paper concludes with recommendations for future research studies using crosslinking agents with different types of modified asphalt binders.