Cationic asphalt emulsions are used for most road applications since they break and set quickly. The majority of aggregates have a negatively charged surface, and once the emulsion is broken the cationic emulsifiers act as adhesion agents and help to form permanent bonds between the asphalt and the aggregate.
The emulsions are classified into three major categories based on their breaking and setting rates. They are rapid, medium, and slow setting. Different kinds of emulsifiers and emulsion formulations are necessary to design emulsions with different breaking and setting rates. These breaking and setting rates decide the type of application for the emulsion. Applications such as surface dressing or chip real require rapid setting emulsion that would break and set on contact with the aggregate surface. Applications like slurry or cold mix, where a significant amount of mixing time is required before application, require a slow setting emulsion.
Redicote emulsifiers are available to prepare slow, medium, and rapid setting emulsions that can be used in all types of road applications.
Akzo Nobel Asphalt Applications, Inc., 4914 Fort Avenue, P.O. Box 7677, Waco, TX 76710. Tel: 254-772-7677; Fax: 254-772-7246.