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This one-page flyer pertains to report 2016RIC08, Synopsis of Recycled Asphalt Pavement (RAP) Material.

This presentation pertains to report 2014RIC14, Integrated Tools for Pavement Design and Management.

The Minnesota Department of Transportation (Mn/DOT) has experimented with the use of shingle scrap in hot mix asphalt (HMA) since 1990. To date, the source of the shingle scrap has been shingle manufacturers exclusively. The manufactured shingle scrap consists primarily of tab punch-outs but also contains some mis-colored and damaged shingles. Test sections were constructed on the Willard Munger Recreational Trail, T.H. 25 in Mayer, Minnesota and on County State Aid Highway (CSAH) 17, in Scott County, Minnesota. Not only are the test sections performing as well as the control sections, but using shingle scrap reduces the amount of virgin asphalt cement required in a bituminous mix, thus creating the potential for a cost savings when using shingle scrap in HMA. Based on the performance of these lest sections, shingle manufacturing scrap is now an allowable salvage material in hot mix asphalt under Mn/DOT specification 2331.E2e, Recycled Mixture Requirements. This report outlines the history of shingle scrap use in Minnesota, presents laboratory and field performance data and contains the current Mn/DOT specification allowing shingle scrap to be used as a salvage material in HMA pavements.

This project evaluated the field and laboratory performance of Recycled Asphalt Pavement (RAP) and Fractionated Recycled Asphalt Pavement (FRAP) test cells at the Minnesota Road Research project (MnROAD) between 2008 and 2012. Project scope included: developing specifications, construction of FRAP and RAP test cells at MnROAD, field performance evaluations, and laboratory testing of binders and mixtures on 11 test cells. The final report was published as Report 2012-39, " MnROAD Study of RAP and Fractionated RAP."

During the Arab Oil Embargo of 1973, the price of crude oil quadrupled to $12 per barrel. Subsequently the price of asphalt, the bottom of the crude oil barrel, also increased significantly during this time and the cost of highway construction and rehabilitation rose dramatically. Contractors and equipment manufacturers quickly recognized that recycling reclaimed asphalt pavement (RAP) could provide many benefits and opportunities. Milling machines were developed, hot mix asphalt plants were modified to allow the addition of RAP to mixes, and soil stabilization equipment was redesigned to reclaim existing pavements in-place.

This report provides a brief overview of recent research and current usage of various pavement-related topics in Minnesota, including: -Use of RAP in local pavement design, -Implementation of an updated vehicle classification scheme, -Pavement design charts for ten-ton designs, -Revision and update of the FWD Viewer Tool, and -Overlay design method for the FWD Viewer Tool. The review of these topics includes recommendations for further study or for implementation. The two topics related to the FWD Viewer Tool were investigated further, including implementation which was included in this project. Implementation activities included development of spreadsheet tools and statewide training among local transportation engineers for their use.

This Technical Summary pertains to the LRRB-produced Report 2014RIC14, “Integrated Tools for Pavement Design and Management,” published February 2014.

Recycled Asphalt Pavement (RAP) is encouraged to be used in the construction of new roadways and pavements. Its use reduces cost and environmental impacts of road construction by reusing existing asphalt pavement. In Minnesota existing asphalt pavement material is often crushed and blended with other aggregates to create aggregate base or shouldering materials or transported to an Asphalt plant, crushed, and incorporated into new asphalt material. Both strategies reduce demand for virgin aggregates. Incorporation into new asphalt material has the additional benefit of reducing demand for asphalt binder material. It is recognized that a greater benefit to the environment and economy can be realized when incorporated into new asphalt material. This document was developed as a reference for local agencies that have minimal knowledge of incorporating RAP material into new asphalt and would like to understand more.

Full-depth reclamation (FDR), a common strategy on rural roadways to reduce costs for materials and hauling, was validated to be a viable long-term and cost-effective option for urban and suburban asphalt pavement rehabilitation. These findings were published in two Minnesota Local Road Research Board studies from 2016. However, statewide application of Urban FDR is yet to be attained in Minnesota or widely adopted by city and county public works departments. To help cities and counties determine feasibility, the Minnesota Local Road Research Board developed informational materials on how to conduct Full-Depth Reclamation (FDR) within urban areas (i.e. curb-and-gutter, utilities, storm sewers, manholes, etc.). Topics include: •Basic Overview of FDR •FDR Candidate – What to Consider •Specification/Construction Inspection •Cost This report has two appendices.

Appendix X to Report 2021RIC02, detailing results of a survey on full depth reclamation (FDR) taken by city and county engineers in Minnesota.

This appendix reprints the special provisions for Full Depth Reclamation (FDR) according to the 2018 edition of the Minnesota "Standard Specifications for Construction. It was provided by the city of Shoreview, Minnesota.

A brief FAQ sheet regarding the use of Full Depth Reclamation (FDR) in urban settings.

This Technical Summary pertains to Report 2012-39, “MnROAD Study of RAP and Fractionated RAP,” published December 2012.

Modern asphalt mixtures are usually a combination of various materials from different sources, including reclaimed asphalt pavement (RAP) and recycling agents (RAs), and are used to attain sustainable growth. However, the lack of a well-established method for determining compatibility between various sources and types of virgin binder, aged binder within RAP, and RAs has been a major impediment in current asphalt material selection and specification. Therefore, the objective of this study was to evaluate various binder and mixture testing methods to characterize the compatibility between complex components of asphalt mixtures, specifically from the perspective of assessing their cracking performance. The primary evaluation consisted of laboratory-prepared materials that used three RAP sources, three asphalt binders (one PG 58–28, two PG 64–22), and two RAs (petroleum-based and bio-oil-based) for both binder and mixture characterization. The binder tests consisted of rheological characterization using the dynamic shear rheometer (DSR) and thermal analysis using the differential scanning calorimeter (DSC), whereas the mixture tests included complex modulus (E*), semi-circular bend (SCB), and disk-shaped compact tension (DCT) tests. The results indicated that the rheological characterization of asphalt binder and mixture may not adequately capture the incompatibility between virgin binder, RAP, and Ras. However, binder DSC analysis and mixture fracture tests have shown promising results for evaluating the compatibility of various mixture components. Therefore, the findings of this study provide agencies with a framework to select the most compatible component materials from various sources for their projects.

Asphalt rejuvenators, or recycling agents (RA), are used to incorporate higher amounts of Reclaimed Asphalt Pavement (RAP) in Hot Mix Asphalt (HMA) without detrimentally impacting the long-term performance of the pavement. The National Road Research Alliance (NRRA) Flexible Team constructed field test sections as part of a mill and overlay project in northern Minnesota in August of 2019. These field sections included wearing courses with 40% RAP that incorporate seven different RA products, with the dosage determined by the supplier to meet a target extracted and recovered performance grade (PG) of XX-34. In addition to the RA test sections, there were control sections with 40% RAP and 30% RAP (the maximum level allowed on the remainder of this project). The objective of this research project was to evaluate the effectiveness of the seven RA products over time and evaluate their performance as compared to the control mixtures. This was accomplished through a combination of binder (chemical and rheological) and mixture characterization and performance testing using different laboratory aging levels, field core testing, and performance monitoring of the field sections over time. This report documents the results after four years in service with cores taken annually. The study showed that all RAs exhibit improved rheological properties in 1-year field cores. However, the benefits of RA diminish with field aging, and after four years, some RAs show comparable properties with controls. In terms of mixture properties, the inclusion of RA enhances both rheological properties and fracture and fatigue crack resistance initially.