Performance Properties of Polymer Modified Pelletized Asphalt Mixtures

In general, asphalt binder used in various paving applications needs to be heated and kept in a liquid state in order to achieve the good workability of a binder required for these applications. This study would examine the use of pelletized binders instead of those conventional binders in various pavement types. The pelletized binder materials are produced by first mixing virgin asphalt binder (e.g., PG 64-22) and various crumb rubber modifiers (CRM) together to produce the polymerized binders. After the reaction between the CRM and virgin binder has taken place, the hot binder is introduced into the pelletizing machine along with a stiffener (e.g., hydrated lime) to produce the pellets. Then, these pellets are cooled, and a coating is applied to prevent coagulation. The final binder matrix is polymerized asphalt (e.g., PG 76-22). The paper discusses major properties of pelletized mixtures used in many laboratory and field projects.