Implementation and Performance Evaluation of The Large-scale High-Rubber-Content Asphalt Projects in Michigan

Description

Implementation and Performance Evaluation of The Large-scale High-Rubber-Content Asphalt Projects in Michigan

Meng Wu^a, Dongzhao Jin^a, Zhanping You^a*

^aDepartment of Civil, Environmental, and Geospatial Engineering

Michigan Technological University, Houghton, MI, 49931, USA

corresponding authors: zyou@mtu.edu

ABSTRACT. Recycling scrap tires as crumb rubber in asphalt pavements provides an environmentally sustainable waste management strategy while enhancing pavement performance. This paper presents two demonstration projects in Michigan: a pilot project in Kalamazoo County and a much larger project on Dixie Highway in Saginaw County, both employing high-rubber-content asphalt mixtures. In Kalamazoo, approximately 24% crumb rubber by binder weight was incorporated into a chip seal and thin overlay via the dry process. In Saginaw, a wet-process crumb rubber-modified asphalt containing 22% crumb rubber by binder weight was applied as an overlay on existing concrete pavement. For each project, the mix design, construction process, and laboratory performance evaluations are detailed. Results indicate that high rubber contents improve rutting resistance, cracking resistance, and overall durability. Hamburg Wheel Tracking Test results showed all rubberized mixtures withstanding over 7,500 passes with rut depths below 20 mm. Cracking Test results demonstrated fracture energy or CT Index values three to four times higher than those of the control mixtures, indicating markedly superior cracking resistance. Overall, these projects confirm that high-content crumb rubber modified asphalt can be produced and paved using standard equipment, delivering pavements with excellent cracking performance, adequate rutting resistance, and significant environmental benefits through tire waste diversion. These findings support the feasibility of large-scale implementation of high-rubber-content asphalt for durable and sustainable road infrastructure in cold climates in Michigan.

KEYWORDS: Crumb rubber, Crumb rubber modified asphalt, High rubber content, Mixture performance