Report On Cold Recycling Of Asphalt Pavements

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.

The responsibility of Task Force No. 38 was defined to be as follows: The Task Force would address the cold processing of reclaimed asphalt pavement (RAP) with or without additional additives and/or aggregates to create a rehabilitated component of the pavement structure. This report contains information on the cold recycling process, project selection and assessment, cold recycled mixture and pavement structural design, quality control and testing, guidelines for construction specifications and definitions of terms.

Pavement recycling is a technology that can restore the service life of pavement structures and stretch available funding for pavement rehabilitation. In general, pavement recycling techniques remix the existing pavement material and reuse it in the final pavement in the form of a stabilized layer. Limitations to further widespread implementation of pavement recycling processes have been reported in previous national research efforts. The TRB National Cooperative Highway Research Program's NCHRP Research Report 960: Proposed AASHTO Practice and Tests for Process Control and Product Acceptance of Asphalt-Treated Cold Recycled Pavements investigates and recommends a series of tests that could be used for the purpose of implementing rapid quality tests that can be used to assess the time to opening to traffic and time to surfacing a newly constructed recycled layer.

After some success in the process of recycling asphalt pavements in 1975, Kossuth County decided to implement further recycling projects on a larger scale in its 1976 road construction program. The work done in 1975 indicated that a quality product could be produced, but that an air pollution problem created during the heating and mixing operation must be brought under reasonable control. As part of its 1976 road program, Kossuth County planned to salvage a total of 16 miles of old asphalt pavements in three projects. Two of these projects were three miles in length and the third project was ten miles long. The ten mile project was selected by the Federal Highway Authority as one of the recycling projects to be completed in cooperation with Demonstration Project No. 39, Recycling Asphalt Pavements.

This volume highlights the latest advances, innovations, and applications in the field of asphalt pavement technology, as presented by leading international researchers and engineers at the 5th International Symposium on Asphalt Pavements & Environment (ISAP 2019 APE Symposium), held in Padua, Italy on September 11-13, 2019. It covers a diverse range of topics concerning materials and technologies for asphalt pavements, designed for sustainability and environmental compatibility: sustainable pavement materials, marginal materials for asphalt pavements, pavement structures, testing methods and performance, maintenance and management methods, urban heat island mitigation, energy harvesting, and Life Cycle Assessment. The contributions, which were selected by means of a rigorous international peer-review process, present a wealth of exciting ideas that will open novel research directions and foster multidisciplinary collaboration among different specialists.

This book presents the detailed results of five task groups of the RILEM technical committee TC 237-SIB on Testing and Characterization of Sustainable Innovative Bituminous Materials and Systems. It concentrates on specific new topics in asphalt binder and mixture testing, dealing with new developments in asphalt testing, in particular also in view of new innovative bituminous materials, such as hot and cold recycled mixtures, grid reinforced pavements and recycled Reclaimed Asphalt Pavements (RAP), where test methods developed for traditional asphalt concrete are not a priori applicable. The main objective is providing a basis for pre-standardization by comparing different test methods and showing ways for fundamental improvements. Thus, the book also points the way for a further advanced chemo-physical understanding of materials and their role in pavement systems relying on fundamental material properties and suitable models for describing and predicting the intrinsic mechanisms that determine the material behavior.