PRACTICAL EXPERIENCE WITH HIGH RATIO HOT MIX RECYCLING ---PROCEEDINGS OF THE THIRTY-SECOND ANNUAL CONFERENCE OF THE CANADIAN TECHNICAL ASPHALT ASSOCIATION

The consistent production of quality recycled hot mix incorporating a high recycled asphalt pavement content (50/50 and greater) requires a representative Marshall mix design, proper processing, selection of an appropriate asphalt cement and drum plant operations which limit moisture content, mix uniformly and meet environmental conditions. This paper outlines the steps in recycled hot mix design. In Ontario, softer grades of asphalt cement are incorporated in recycled hot mix to soften the old mix. Procedures to estimate the necessary penetration of the added asphalt cement are presented. Quality control results from typical highway and municipal recycled pavement projects show recycled hot mix quality to be equivalent to or better than conventional hot mix.