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Title: Development of superior asphalt recycling agents. Phase 1, Technical feasibility. Technical progress report

Technical Report ·
DOI:https://doi.org/10.2172/117734· OSTI ID:117734

About 27 million tons of asphalt and nearly twenty times this much aggregate are consumed each year to build and maintain over two million miles of roads in this country. Over a cycle of about 12 years on the average, these roads must be reworked and much of these millions of tons of rock and asphalt cannot be reused with present recycling technology. Instead, much of the maintenance is accomplished by placing thick layers (hot-mix overlays) of new material on top of the failed material. This results in considerable waste of material, both in terms of quality aggregate and in terms of asphalt binder. In addition, the new asphalt binder represents a significant source of potential energy. The main impediment to recycling asphalt binder is the poorly developed science of recycling agent composition and, as a result, optimum recycling agents are not available. An excellent recycling agent should not only be able to reduce the viscosity of the aged material, but it must also be able to restore compatibility. The properties of the old material and recycling agent must be compatible to give both good initial properties and aging characteristics, and this must be understood. The agent must also be inexpensive and easily manufactured. A large quantity of potential feedstock for the production of recycling agents is available and much of it is now fed to cokers. This material could be recovered by supercritical extraction which is an existing refinery technology. A supercritical pilot plant is available at Texas A&M and has been used to produce fractions for study. The objective of this research is to establish the technical feasibility of determining the specifications and operating parameters necessary to produce high quality recycling agents which will allow most old asphalt-based road material to be recycled.

Research Organization:
Texas A and M Univ., College Station, TX (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FC04-93AL94460
OSTI ID:
117734
Report Number(s):
DOE/AL/94460-1; ON: DE95016702
Resource Relation:
Other Information: PBD: Jul 1995
Country of Publication:
United States
Language:
English