TERRA E-News, January 2013 – Volume 7, Number 1
The Michigan Department of Transportation (MDOT) has long used recycled crushed concrete from old pavements as the aggregate base for new pavements. In the early 1990s, MDOT began stabilizing these unbound crushed aggregates with either emulsified asphalt or portland cement. The motivation for this practice was an environmental one—to prevent potential leaching of the cementitious fines in the crushed aggregate. Over time, however, data from the department’s pavement management system (PMS) began to show another benefit: The majority of pavement sections constructed on stabilized permeable bases were significantly outperforming their unbound-base counterparts. To follow up, the joint MDOT–University of Michigan research project, “Improving Pavements with Stabilized Base Designs,” evaluated the PMS data, documented the performance of these pavements, and found that stabilization of the permeable recycled concrete base was not only environmentally smart, but also produced long-life, sustainable concrete pavements. These pavements are characterized by significantly less cracking, better initial ride quality, and superior ride quality throughout the pavement service life. As a result of this research, MDOT has continued to identify opportunities to stabilize recycled concrete pavement bases with portland cement concrete. Two recent projects included I-96 in Clinton and Eaton counties and I-94 in Jackson County. Download the report: Performance Evaluation of JRCP with Stabilized Open-Graded Drainage Course (1.2 MB PDF).