ASPHALT CONCRETE RECYCLING IN CANADA

Asphalt recycling has become a key component of the Canadian paving industry, and it is critical that the appropriate technology is adopted to ensure that the desired pavement quality is achieved. The range of cold and hot asphalt recycling procedures is reviewed in terms of applicability, limitations, and practical experience, and an outline of suggested engineering specification and testing requirements is given. Production of high-quality recycled hot mix incorporating a high content of reclaimed asphalt pavement requires a consistent processed reclaimed asphalt, appropriate new asphalt cement properties, representative Marshall mix design, proper hot-mix plant operations, and quality control/quality assurance to conventional hot-mix requirements. For cold or hot in-place asphalt recycling, evaluation of the existing pavement for suitability and selection of appropriate procedures and materials is emphasized. Research needs such as fine manufactured sand for recycled hot-mix voids development, fatigue and rutting resistance performance of recycled mixes, and rejuvenators for in-place recycling are identified. Experience indicates that asphalt recycling is technically sound and economically favorable and that it clearly contributes to sustainable development by conserving materials, energy, and landfill.