PRACTICAL EXPERIENCE WITH EMULSION COLD IN-PLACE RECYCLING AND FOAMED ASPHALT FULL DEPTH RECLAMATION
Enhanced asphalt pavement recycling and reclaiming techniques, such as cold in- place recycling (CIR) and full depth reclamation (FDR), are increasingly important to improved life-cycle performance and cost-effective pavement rehabilitation, particularly with escalating energy and asphalt binder costs. Asphalt pavement recycling contributes to sustainable transportation infrastructure through reduced natural resources requirements (aggregates, asphalt binders and fuels) and environmental impacts. Practical Canadian, American and Colombian applied design, materials and construction experience with CIR (emulsion and foamed asphalt) and FDR (foamed asphalt and lime/foamed asphalt) is used to illustrate the processing features, overall project design procedures (pavement section evaluation, reclaimed asphalt pavement properties, structural design, materials selection and mix design), construction requirements, appropriate specifications, quality control/quality assurance and anticipated flexible pavement performance involved. The performance of quality CIR and FDR has been positive and cost-effective, particularly for rutting resistance and reflective cracking mitigation. Innovations with CIR and FDR, such as improved mix design procedures, lime use (enhanced stripping resistance and strength development), laboratory characterization (moisture susceptibility, rutting resistance, resilient modulus and fatigue endurance), higher heavy traffic levels use, mechanistic pavement design parameters, including temperature relationships, incorporation in long-life asphalt pavement structures and probabilistic life-cycle costing, are presented with implementation guidance..