Tire-Derived Aggregate Used in Roadway Repairs/CALRecycle Reimbursement Grant Program

Santa Barbara County Public Works partnered with the CalRecycle TDA program to reconstruct a failed roadway embankment using recycled tires for the Ortega Ridge Road Slide Repair project, restoring an unsafe road and diverting over 80,000 tires from California’s landfills in the form of Tire-Derived Aggregate (TDA) fill.

Ongoing settlement resulted in cracks growing up to six inches wide and deep. In 2015, the county closed the roadway. At that time, more than 30 inches of asphalt had been placed on the roadway over the years. This Project combined the use of TDA and Mechanically Stabilized Earth elements, “dubbed MSTDA”. Using this innovative combination, the county streamlined design and construction, reduced environmental impacts, created a smaller construction footprint, and realized cost savings.

This is one of 15 recent MSTDA and TDA backfill road repair solutions completed in 2019-2020 by public works departments in Santa Barbara, Tuolumne and Yuba Counties.

This presentation will highlight some of the newly completed road repairs, how Tire Derived Aggregate (TDA) and Mechanically stabilized TDA (MSTDA) were used to fix a multitude of different road failures. TDA properties and road repair methodologies will be discussed and outlined using recent projects as illustrations. The CalRecycle TDA reimbursement grant will also be outlined and information on how to utilize the grant will be shared.

Joaquin Wright is a Sustainable Resource Engineer and Tire Derived Aggregate (TDA) specialist for GHD Inc. He has worked actively with TDA since 2000. He obtained his BS in Environmental Resource Engineering from Humboldt State University (HSU). He is a credentialed Sustainability Professional with the Institute for Sustainable Infrastructure (ISI), and has extensive experience in the area of Landfill Design, Environmental Remediation, as well as Recycled Material Evaluation for use in civil engineering applications. His experience with recycled materials research in California includes TDA, waste Carpet, and waste mattress components. Joaquin has managed and authored numerous recycled material evaluations, white papers, research projects, pilot studies, and outreach efforts funded by CalRecycle, CARE and the MRC. He has been an adjunct professor at HSU teaching Solid Waste Design and is currently an active member of the US Scrap Tire Work Group and is the current Chairperson for the Civil Engineering Committee as well as the technical contact for ASTM D6270-20, “Standard Practice for Use of Scrap Tires in Civil Engineering Applications”.

Joaquin is an avid Kayak fisherman of the Sonoma and Mendocino coasts and recently got to enjoy some time with humpback whales near Fort Ross!  “It’s true! I even recorded some video that day”