Pollution Prevention

Since its inception, the SRP has provided support and guidance for demonstration projects that incorporate the use of recycled content. These projects have been performed statewide and have been the product of ideas initiated from manufacturers, district personnel, Pennsylvania residents, contractors, and recyclers. The following fact sheets were created for informational purposes. Each fact sheet provides a summary of a demonstration project completed to test the capabilities and, in some instances, the limitations of recycled content products in transportation-related projects.

Featured Demonstration Project Fact Sheets:

• Crumb Rubber (PDF)
• Hot-In-Place Recycling of Asphalt Pavement (PDF)
• Plasphalt (PDF)
• Post-Consumer Shingles (PDF)
• Reclaimed Concrete Aggregate (PDF)
• Rubber Noise Walls (PDF)
• Tire Shreds (PDF)

The fact sheets listed are not all encompassing. Additional recycled content materials have been researched and tested via PennDOT demonstration projects. To inquire about a specific project or recycled material usage, contact the SRP team at PennDOTSRP@pa.gov.

Picnic Tables Manufactured From Recycled Plastics

Due to its ease of use, plastics are a preferred and inexpensive material used by manufacturers for everyday packaging and easily replaceable goods. As a result, large volumes of these single-use plastics are delivered to recycling facilities despite an immature market for these recycled 'wastes'. As one of the Commonwealth's largest consumers of raw materials, the PennDOT SRP feels a duty exists to identify recycled plastic material substitutions for traditional products or materials where an engineering or cost benefit exists.

To contribute to the recycling of waste plastics, the SRP supported the purchasing of picnic tables constructed of recycled plastic lumber for several districts that required upgrades/replacement of equipment at public rest areas and maintenance facilities. As seen in these photos, District SEMP Coordinators, like Lois Watcher in District 3, are encouraged to submit requests for support in purchasing materials containing recycled content to upgrade their facilities. Not only are these plastic picnic tables sustainable — their longevity far surpasses those comprised of wood or other easily compromised material — they require less maintenance and are easier to move and keep clean.

Joint Agency Assessment of Plastic Road Additive

In response to the Commonwealth's need to recycle waste mixed plastics, the SRP focused efforts to identify opportunities to recycle large quantities of hard-to-recycle waste plastics in PennDOT improvement projects. After more than two years of research, testing, and collaborative planning, in October 2021, a demonstration project using an asphalt modifier manufactured with recycled plastics was used in a replacement pavement project in Ridley Creek State Park. This Delaware County project represents a cooperative effort among PennDOT, the Department of Conservation and Natural Resources (DCNR), and the Department of Environmental Protection (DEP). The SRP's technical team led the research, planning, and coordination for this demonstration project that includes five years of performance monitoring and reporting to stakeholders and the public.

The project includes two quarter-mile sections where the recylced plastic asphalt modifier was used as a 2% additive to the binder in the road's wearing course. While this does not seem like a lot, this equates to approximately 150,000 single-use plastic bags. In addition to recycled plastic, this full-depth reclamation project also employed recycling of the existing road/base material and approximately 30% of the asphalt pavement contained recycled millings.

This project and material being tested support interagency goals to increase the Commonwealth's sustainability in operations. Potential benefits include:

• Extended useful life of asphalt pavements;
• Reduction in maintenance needs;
• Diverting waste plastics from landfills and helping to establish a viable market for these plastics;
• Diminishing the petroleum binder used in asphalts; and,
• Continued ability to reuse asphalt millings in future paving projects.

Over the next five years, PennDOT's SRP team will monitor the technical performance and conduct evaluations of microplastics release. The sections paved with the plastic asphalt modifier will be compared to adjacent sections that were paved using a conventional asphalt blend. Since this material is new to PennDOT and most DOTs in the United States, during the completion of this project, both the contractor (Allan Myers) and the manufacturer of the recycled plastic modifier (NVIAMG) performed supplementary evaluation/planning efforts when requested by PennDOT or DCNR. Ultimately this recycled plastic asphalt modifier was chosen because:

• It is readily stored, handled, and easily added to the pavement at the asphalt plant;
• It completely melts within the asphalt bitumen binder;
• Other state DOTs have reported successful pilots of this type of product; and,
• Laboratory testing shows the asphalt modifier helps bind other deleterious materials within the asphalt mix.

The importance and acceptance of this inter-department collaborative project received positive support and acknowledgment.

During a project press conference on November 8, 2021, the PennDOT Acting Deputy Secretary for Highway Administration Mike Keiser said, "Transportation is integral in our communities and we are always evolving our operations. ... We are very pleased when we can pursue innovations bringing benefits to the public, our transportation assets, and our environment."

The DCNR Secretary Cindy Adams Dunn echoed Kaiser and stated, "Sustainability is at the core of DCNR's mission, and we are pleased that one of our 121 state parks was selected to be a part of this innovative pilot project. ... We look forward to testing this new technology based on the expected benefits and are hopeful that it is a model for future successes in Pennsylvania, especially with regards to state agencies collaborating to create more sustainable operations and policies across the Commonwealth."

An overview video of the Ridley Creek State Park paving project uses drone footage captured during and after construction. The expected environmental and performance benefits gained through the use of the recycled plastic asphalt modifier are summarized, and the participants in this multiple state agency demonstration program are acknowledged.

Check back for updates as the SRP reports on this project's performance characteristics and posts additional information on future demonstration projects that contribute to improving the sustainability of the Commonwealth's infrastructure.

Questions? Contact the PennDOT SRP at PennDOTSRP@pa.gov.

​It is the ultimate goal of the SRP to identify and promote recycled materials applications that offer equal or enhanced performance or cost advantage over virgin/conventional materials.

NEW PRODUCTS/MATERIALS FOR CONSIDERATION

All new products proposed for use by PennDOT must be evaluated and approved prior to use.  To assist with this effort, the SRP may provide support to manufacturers who submit their products for evaluation to the New Products Evaluation Program or the Pennsylvania State Transportation Innovation Council (STIC) Innovation Program.

The process by which PennDOT evaluates material to be published in Bulletin 15 (PDF) is described below and can be found on the PennDOT Research and Testing web page.  It should be noted, this evaluation process is intended for material that adheres to the requirements of Bulletin 15.  If a material's intended use is for low-volume roadways (Publication 447 (PDF)), there is a separate process for evaluation.

To learn more about the STIC Innovation Program and how to submit a new innovation for consideration, visit the STIC web page.

PENNDOT RESEARCH AND TESTING

To begin the PennDOT New Product Evaluation process, it is the responsibility of a manufacturer to submit a product evaluation application for PennDOT consideration.  The PennDOT Bureau of Product Development, New Product Innovation Section, is responsible for reviewing all submitted product evaluation applications.  The application form (PDF) as well as the process by which new product evaluation applications are submitted can be found on the PennDOT New Products Evaluation and Research web page.

Once a new product has been approved (conditional or unconditional) for use in Commonwealth transportation projects and the associated use specification or special provision has been defined, the SRP may also aid with initiating a demonstration project or as an informational liaison to statewide districts or municipal personnel.

Since the inception of the SRP, the program has provided assistance for research of many recycled materials which includes but is not limited to the following:

Recycled Material Fact Sheets:

• Reclaimed Asphalt Pavement (PDF)
  
• Recycled Concrete Aggregate (PDF)
  
• Recycled Glass (PDF)
  
• Rubber - Shreds, Chips, and Ground (PDF)
  

​PennDOT maintains established methodologies for the approval and development of all specifications and special provisions; however, the SRP is primarily involved with construction-related material/product specifications and special provisions.  Construction-related material specifications are maintained in Publication 408 (PDF) "Construction Specifications for PennDOT Projects" and Publication 447 (PDF) "Approved Products for Lower Volume Roadways."  Special provisions are maintained electronically in the PennDOT Engineering and Construction Management System (ECMS); PennDOT does not maintain a hardcopy format.  A current listing of all standard special provisions, by index, may be found on the ECMS website by clicking on "Construction Projects" then "Resources" and "Special Provisions."  The SRP has created a catalog (Excel) of all specifications listed in Publication 408 that allow for the incorporation of recycled materials.

For more information on the maintenance and announcements of specifications and special provisions, visit the PennDOT Construction Specification webpage.

PennDOT also maintains an online repository of completed, archived, and on-going research projects.  The database lists projects by status (active, archived, and completed) and categories (construction, design, maintenance, multimodal, operations & safety, and planning & policy).  These research projects are not conducted solely by PennDOT; they may be collaboration efforts where other state DOTs, universities, or federal agencies are involved.  Many of the projects listed in this database may also focus on advancing the use of recycled materials/products, or methodologies for recycling/reusing of existing materials.  Projects completed under the SRP are not recorded/maintained in this database; however, the database can be used to search for active/completed PennDOT research efforts prior to submitting a request for a new research project.

​Outreach is a critical element in identifying beneficial material use opportunities for the department.  The success of the SRP would not be possible without collaboration with internal and external partners and various stakeholders.

Outreach with internal partners typically includes quarterly meetings, email correspondence, attending webinars, and attending conferences that focus on department specialties.  These partners include, but are not limited to, the STIC, the New Products Innovation team, and the eleven districts' design, construction, and maintenance departments.  This allows these parties to become aware of recycled materials uses, limitations of use, and prospective recycled materials generated by the department's operations.

External partnerships are also vital to the success of the SRP.  Fostering these relationships allows PennDOT to understand the recycling needs of all areas of the Commonwealth, sources of recycled materials purchased, and locations of materials recycling operations.  The SRP can play an active role in identifying ways to reduce specific waste streams, eliminate obstacles that industry or constituents face, and help to promote specific recyclables used by PennDOT.

Outreach is also accomplished by attending and presenting at various workshops/conferences and speaking engagements that focus on the same principles as the SRP.  By participating at these events, there is greater potential to identify new markets or new materials/products that were not previously considered for application in transportation projects or materials/products that have a non-roadway use (i.e. rest area fixtures).  Many workshops/conferences are annual events that bring together experts to share the latest knowledge, expertise, and experience in development and integration of proactive environmental management systems and sustainability concepts into transportation programs.  The SRP continuously seeks opportunities to encourage the use of recycled content products/ideas, seek out new material uses, and apply lessons-learned by other DOTs.

If there is a workshop/conference applicable to SRP principles and goals, please submit suggestions to PennDOTSRP@pa.gov for consideration of SRP attendance.

​Contracting plays a role in all key focus areas of the SRP; however, most importantly, the SRP assists districts in contract bidding where the use of recycled materials is identified.  This is especially important where recycling funds are used in the project.  While a 'bid preference' cannot be used in evaluation and selection of lowest responsive bidder submissions, the SRP seeks to understand where recycled materials are considered and the quantities of recycled materials anticipated and actually used in department projects.  The SRP also shares information on alternative means of including recycled materials in construction projects through District Engineer approvals and Bulletin 14 or 15 approvals.

Even during periods where no new projects with recycled materials content are constructed, the SRP team continues performance evaluations with district and laboratory staff.  This includes the five-year post-completion evaluation required for the approval as a specification/special provision, distribution of laboratory tests, updates to qualify control or provisional specifications to account for new information, assessment of construction level-of-effort from contractors, sharing of performance data with Federal Highway Administration (FHWA) or other state DOTs, working with recycled materials providers to improve their product, understanding/feedback from contractors during the materials deployment, etc.  In the end, there are a multitude of data and insights from contractors and suppliers that must be reviewed and assessed as part of a continuous improvement program to maximize the benefits of recycled materials uses.