Impact of Binders from Waste Materials on Performance of Surface Mixtures
https://apps.dot.state.nc.us/Projects/Research/ProjectInfo.aspx?ID=3083
Record Type: DOT

As materials and construction costs continue to increase, there is a strong interest by both Agencies and Industry to develop ways to include more recyclable materials in asphalt pavements. With both cost savings and sustainability in mind, the North Carolina Department of Transportation (NCDOT) has increased allowances for recycled materials in hot mix asphalt (HMA) in the past few years. The two recyclable materials that receive the most use in North Carolina are recycled asphalt pavement (RAP) and recycled asphalt shingles (RAS). With respect to recycled shingles, the NCDOT has also begun allowing waste shingles from the re-roofing of buildings in HMA.In this project, NCDOT's current specification for designing recycled HMA mixes will be compared to other agencies, specifications and/or research practices. The specific objectives of this research project will be to extend the investigation in the ongoing RP 2012-04 of various sources of recycled binder including Recycled Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) to determine limits for the amount of allowable recycled material based on Performance Grade (PG) binder testing to S9.5C and S9.5D mixes. Application of the binder limits for B mixes to C and D mixes is inefficient due to different virgin binder grades as specified in NCDOT's specifications, as well as different aggregate gradation. Using the allowable amount of recyclable materials, the effects on HMA mixes will be determined through material performance. The objectives of this research will be met by recovering the binder from the recycled materials and performing Performance Grade (PG) testing on the binders. Once this is complete, the limits for the allowable amounts of RAP, RAS and PRAS will be determined due to the binder rheology. Once the limits have been determined, Dynamic Modulus and Flow Number Tests will be performed. A draft specification will be developed at the end utilizing the limits for the recycled materials based on the recycled binder percentage in the mix.
Start date: 2012/8/16
End date: 2014/8/15
Status: Active
Contract/Grant Number: 2013-06
Total Dollars: 228000
Source Organization: North Carolina Department of Transportation
Date Added: 06/12/2012
Index Terms: Wastes, Binders, Mix design, Hot mix paving mixtures, Recycled asphalt pavements, Performance grade, Asphalt shingles, Asphalt mixtures,

North Carolina Department of Transportation
www.ncdot.org/doh/preconstruct/tpb/research/
Research and Development
1549 Mail Service Center
Raleigh, NC 27699-1549
USA
Phone: (919) 508-1790
Fax: (919) 715-0137

Kadibhai, Mustansir A.
Phone: (919) 508-1819
Fax: (919) 715-0137
Email: mkadibhai@ncdot.gov

North Carolina State University, Raleigh
Department of Civil Engineering, Campus Box 7908
Raleigh, NC 27695-7908
USA

Khosla, N. P.
Phone: (919) 515-7835
Fax: (919) 515-7908
Email: khosla@eos.ncsu.edu