Bio-Solvents in the Production of Emulsified Prime Coat Systems

摘要

Petroleum-based solvents are widely used in the production of Emulsified Asphalt Primer (EAP). Thesesolvents have the capability of lowering the viscosity of asphalt and enabling the emulsified asphaltprimer to penetrate through the tightly knitted surface of compacted granular base course. Forenvironmental reasons, this practice is being challenged as it leads to evaporation of Volatile OrganicCompounds (VOCs). Consequently, the practice of priming has been declining and alternative solventfreeEAPs have not provided consistent results.Bio-solvents have been developed following “Green Principles” protocols with the specific objective ofreducing or eliminating VOCs. The capacity of bio-solvents to reduce binder viscosity is comparable topetroleum-based solvents. Emulsified asphalt primers produced with bio-solvent have proven to providebinder penetration of granular base course comparable to traditional EAP.This paper provides information on prime coat systems, their purpose, how they work and the variousproducts currently used. The penetration of prime coat systems in compacted granular base course isinfluenced by a multitude of factors including mineralogy, gradation and density. The robustness of anyEAP relates to its aptitude to penetrate granular base course regardless of field conditions. This studypresents an overview of how bio-solvent EAPs were developed to optimize robustness.