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Public Roads - November/December 2015

November/December 2015
Issue No:
Vol. 79 No. 3
Publication Number:
Table of Contents

Training Update

Advancing Asphalt Recycling

by Jason Dietz and Vanessa Almony

Departments of transportation face increasing challenges from tightening budgets and deteriorating roadway conditions on aging infrastructure. To overcome these challenges, State DOTs are looking for ways to assess and modernize their approach to maintaining and managing highway investments.

Using recycled materials can help highway agencies improve their bottom lines--and protect the environment by conserving natural resources and energy. The Federal Highway Administration considers recycling a viable alternative to traditional rehabilitation techniques for asphalt-surfaced pavements. For many projects, in-place recycling and reuse offers an environmentally preferable and cost-effective solution compared to other reconstruction alternatives.

Training to Help You Get It Right

The National Highway Institute’s course 131050, Asphalt Pavement In-Place Recycling Techniques, is a 2-day, instructor-led session designed to give DOT staffers the knowledge they need to use these techniques successfully. The course is intended for State and local transportation agency engineers and those responsible for selecting, designing, or constructing projects for asphalt pavement maintenance, resurfacing, rehabilitation, and reconstruction alternatives.

Prior to attending the classroom portion, participants complete two Web-based modules that introduce techniques for pavement evaluation, potential recycling methods, and the types of equipment commonly used for each. The classroom session focuses on project and technique selection and justification, materials considerations and mix designs, construction specifications, and project control considerations during construction.

“Course participants also are better prepared to support their agencies as they align with [the Moving Ahead for Progress in the 21st Century Act], which encourages a focus on performance management and pavement measures,” says Timothy Aschenbrener, a pavement and materials engineer with FHWA’s ResourceCenter.

Participants engage in small- and large-group activities to explore current in-place recycling technologies and learn their benefits and factors for successful use. The course is particularly suited to those who are responsible for selecting and designing asphalt in-place recycling projects, writing effective specifications, and inspecting projects during their construction. Contractors, consulting engineers, and industry representatives involved in in-place recycling also can benefit from this course.

Understanding the Benefits

A construction crew uses in-place recycling equipment, shown here, beside a stockpile of reclaimed asphalt pavement.

Instructors underscore the benefits of recycling, known as the three E’s:

Environment: Promoting recycling as the first option to consider during planning encourages environmental stewardship. In-place recycling can reduce construction-related greenhouse gases as compared to conventional mill and overlay strategies by more than 50 percent, and asphalt pavement is up to 100 percent recyclable.

Economics: The cost of in-place recycling is 40 percent to 60 percent of the cost of conventional mill and overlay strategies. Savings come from reusing existing materials and avoiding the costs of milling and removing materials from the site, as well as eliminating dumping fees.

Engineering: Using good engineering design helps to assure longer life of pavements and highway assets. By treating existing distress, pavement life may be lengthened by 3 to 5 years compared to conventional strategies such as leveling courses or mill and overlay combinations.

“Although in-place pavement recycling has been used since the early 1900s,” says Aschenbrener, “the technology has advanced sufficiently to make it more practical today.” NHI’s course aims to help transportation agencies better understand how and when to use in-place recycling, advancing its use and acceptance.

For more information, visit NHI’s Web site at

Jason Dietz is a pavement and materials engineer in FHWA’s Resource Center and is an NHI instructor.

Vanessa Almony is a contracted instructional systems designer with NHI.

2016 Price Changes for
NHI’s Web-Based Courses

On January 1, 2016, NHI will begin charging a small fee for the Web-based training courses developed through a partnership with the Transportation Curriculum Coordination Council (TCCC). Courses will cost $25 to $50 depending on duration. NHI’s Web-based prerequisite courses and those taken in conjunction with blended instructor-led training continue to be available at no cost. For pricing, please view the course details on the NHI Web site.

Participants who enroll in Web-based training will have access to the course for 6 months. After that time, participants need to reregister for the course to access or complete the training. For more information and frequently asked questions, visit