Hot In Place Recycling Of Asphalt Concrete

This synthesis will be of interest to administrators, pavement designers, highway, material, research, and specification engineers, and others interested in economical methods for reconstructing or rehabilitating asphalt concrete pavements. It describes the processes and equipment used for hot in-place recycling of asphalt concrete and provides information on mix designs, performance, and guidelines for its effective use. A significant amount of the information provided is based on the current practices of state highway agencies. As such, numerous case histories are included in the report.

Research and Application of Hot In-Place Recycling Technology for Asphalt Pavement is the first comprehensive book on the topic that presents over two decades of theoretical and practical experience gained in China. The book gives comprehensive coverage of HIPR, including pavement evaluation, distress analysis, mix design, processes and equipment selection, implementation and acceptance criteria. In eight chapters, this book covers HIPR from theoretical and practical viewpoints, and provides detailed case-studies based on real-world experience. This book includes everything engineers need to apply HIPR to improve sustainability and reduce disruption during the maintenance and repair of asphalt. Presents, for the first time in English, decades of experience and research on Hot in-Place Recycling Technology (HIPR) for asphalt pavements Considers all aspects of HIPR, giving engineers all they need to use the technique for road maintenance and repair Details how HIPR drastically improves the sustainability of asphalt and reduces disruption to traffic during repair and maintenance work Includes detailed case studies from thirty years of HIPR in China, giving context and practical know-how

This synthesis will be of interest to pavement designers, construction engineers, and others interested in economical methods for reconstructing or rehabilitating bituminous pavements. Information is provided on the processes and procedures used by a number of states to recycle asphalt pavements in place without application of heat. Since 1975 a growing number of state highway agencies have reconstructed or rehabilitated asphalt pavements by recycling the old pavement in place. This report of the Transportation Research Board describes the processes used for cold in-place recycling, including construction procedures, mix designs, mixture properties, performance, and specifications.

Introductory technical guidance for civil engineers and other professional engineers and construction managers interested in cold recycling of asphalt concrete pavement. Here is what is discussed: 1. INTRODUCTION, 2. BACKGROUND, 3. INITIAL PROJECT SELECTION CRITERIA, 4. TRAFFIC, 5. STRUCTURAL ASSESSMENT, 6. OVERLAY THICKNESS DESIGN, 7. INITIAL STRUCTURAL SUPPORT, 8. PROJECT LENGTH, 9. CURING, 10. UTILITIES, 11. SURFACE TREATMENTS, 12. PAVING FABRICS, GEOSYNTHETICS AND CRACK SEAL, 13. PATCHES, 14. FINAL PROJECT SELECTION, 15. ECONOMIC ASSESSMENT, 16. SUMMARY, 17. SIGNIFICANT IN-PLACE RECYCLING RESOURCES, 18. REFERENCES.

The average thickness of the existing asphalt cement concrete (ACC) along route E66 in Tama County was 156 mm (6.13 in.). The rehabilitation strategy called for widening the base using the top 75 mm (3 in.) of the existing ACC by a recycling process involving cold milling and mixing with additional emulsion/rejuvenator. The material was then placed into a widening trench and compacted to match the level of the milled surface. The project had the following results: (1) Cold recycled ACC pavement provided adequate pavement structure for a low volume road; (2) Premature cracking of the ACC in the widened pavement area was caused by compaction of the mix over a saturated subgrade; and (3) Considerably less transverse and longitudinal cracking was observed with 75 mm (3 in.) of cold recycled ACC and a 50 mm (2 in.) hot mix ACC overlay than with a conventional hot mix overlay with no cold recycling. More research should be done on efficient construction procedures and incorporating longer test sections for proper evaluation.