This Asphalt Rubber Usage Guide is intended for use by Caltrans design, construction, and maintenance managers and engineers, as well as by field personnel involved in placement of asphalt rubber paving materials including hot mixes and surface treatments. The purpose of this Guide is to provide state-of-the-practice information regarding product selection and use, design, production, construction, and quality control and assurance of the asphalt rubber binder, paving materials and spray applications. The intent is to enable Caltrans to optimize the use of asphalt rubber materials to obtain the advertised benefits. This Guide provides an overview of asphalt rubber (AR) materials, components and binder design, and of the benefits and limitations of these materials. This Guide describes the various types of asphalt rubber products available for use in hot mixes and spray (membrane) applications, and presents criteria for selection and use. It also presents information on:
- Mix design criteria,
- Similarities and differences between asphalt rubber and corresponding conventional bituminous applications
- Cost and environmental considerations related to asphalt rubber materials, and
- Guidelines for construction and inspection considerations for asphalt rubber pavements and surface treatments.