1.An Introduction to RAS

2. 3 Aspects of RASEconomicsApplication Science 3. ScienceTodd Scholz, Ph.D., P.E. B.S. (87), M.S. (89), Ph.D. (95), Civil Engineering 25+ years in the industry: Engineering trainee/technician (3 mo. at ODOT, 6 mo. at FHWA) 17+ years in academia (Oregon State, Michigan Tech, University of Nottingham) 8+ years in consulting 5+ years working directly with major construction companies (Kiewit, Granite) Consulting: highway & airfield pavement evaluation/design/rehabilitation projects; city/county/airport pavement management systems; forensic investigations; short courses (training); quality control Research: highway materials (aggregates, asphalt, bituminous mixtures, concrete mixtures); recycled asphalt shingles (RAS) 4. Typical Asphalt ShingleCompositionGranular/aggregate surfacingWaterproofing asphaltAsphalt-impregnated mat (fiberglassor organic felt)Waterproofing asphaltFine granular/aggregate backingComponent Newer, fiberglass-matOlder, organic-mat shingles (%) shingles (%)Asphalt cement19-22 30-36Mat2-15 2-15Mineral granules/aggregate20-38 20-38Mineral filler/stabilizer8-40 8-40Source: Townsend, T., Powell, J., and Xu, C., Environmental Issues Associated With Asphalt ShingleRecycling, Construction Materials Recycling Association, Asphalt Shingles Recycling Project, US EPAInnovations Workgroup 5. Science RAS sources: Manufacturer waste Tear-off shingles Typical RAS composition: Shredded asphalt shingles Minor amounts of construction waste(typically plastic, wood, metal, paper) 6. Science Effect of RAS on asphalt grade: RAS asphalt blends with paving grade (virgin) asphalt(e.g., PG 64-22) resulting in a stiffer blended asphalt Improves resistance to deformation and rutting Theoretically improves resistance to moisture damage Decreases resistance to cracking 7. Science Mix design considerations: Blended asphalt grade RAS asphalt content RAS aggregate content and gradation Deleterious materials 8. Application Rodney Pierce Heritage Environmental Services, LLC. --Director of Sustainable Solutions 15 years in the Environmental Industry the last6+ years in environmental/recyclinginnovation and product development Graduate of Purdue University, WestLafayette, IN., B.S. in Chemistry &Biochemistry 9. Application Using RAS Suggestion would be to Incorporate a separateRecycle bin to feed RAS RAS is NOT a RAP replacement; RAS changes theFine Aggregate Structure and a new mix design isnecessary when using RAS Sensitivity of weight belt and monitoring feed rate Change opening in bin to allow less into mix RAS can also be premixed with RAP or sand priorto mixing process 10. Application Regulations Current regulations allow 5% RAS by volume ofmix Can also be regulated by 30% of the binderreplacement 11. Economics Cost of Virgin Binder $650.00 per ton Cost of RAS $25.00 per ton Asphalt content of of RAS from tear-off 22%-26% per HES test results 12. Economics Approximant cost of RAS Replacement Binder $100 - $110 per ton Cost of RAS Feeder bin implementation $20,000 - $30,000 13. Economics Break Even Point Analysis 450 tons of RAS replacement binder to break evenwith implementation costs After purchase and usage of 450 tons saving$66.00 per ton Total savings yield is $29,700 14. Economics RAS benefits for Commercial and Private work Using softer asphalt can allow more RAS to beadded to a mix RAS + RAP mixes with >40% binder replacementare possible Where RAP is not plentiful, RAS is a goodalternative. 15. 3 Aspects of RASEconomics Saves $ApplicationScienceSimpleBetter product