Minnesota Department of Transportation

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Determining Pavement Design Criteria for Recycled Aggregate Base and Large Stone Subbase

Status:  Active
Project Start Date: November 16, 2017
Project End Date: October 31, 2020

Project Summary:

Although recycled pavement materials have been used in roadway base layers for many years, a specific design method does  not exist that describes how to build roadways with these materials. Many state Departments of Transportation (DOTs) assume recycled base materials behave similar to base layers built with conventional virgin aggregates (VA). There is a similar lack of an existing design methodology for pavement systems built with a large stone subbase (LSSB).

The proposed project has three main goals. The first goal of the project is to determine the field and laboratory performance of materials and lest sections built with recycled aggregate bases (RAB) including recycled concrete aggregate (RCA), recycled asphalt pavement (RAP), and mixtures of these materials with VA. In addition, similar analyses will be conducted for the test sections built with 18 inches thick LSSB with different compaction methods (1-lift and 2-lift), and those 9 inches thick LSSB built with geogrids and geotextiles. To accomplish this goal, the research team will evaluate both the geomechanical and environmental properties of these pavement systems. It should be noted that the LSSB sections have only one type of aggregate base and the multiple recycled aggregate base sections do not have LSSB indicating that experiments for each different design methods are separate. The second goal of the project is to develop a method to estimate the stiffness and permeability of RAB and LSSB designs. This goal will be achieved by establishing correlations between common laboratory test data and both laboratory and field modulus and permeability values. The third goal is to prepare a pavement design and construction specification for roadways built with RAB and LSSB designs. This goal will be accomplished via a summary of the results of  all tasks, taking into account the performance, cost benefits, and life cycle costs of these systems. The outcome of this research will optimize the use of recycled materials and LSSB designs, while maintaining pavement quality, resulting in cost savings   and conservation of natural resources.

Progress Reports

Project Tasks/Status:
Original Need Statement: Recycled Aggregate Base and Large Subbase - 6/14/2017 (Word)
Original Contract Link

Task 1: Literature Review and Recommendations

Task 2: Tech Transfer “State of Practice”

Task 3: Construction Monitoring and Reporting
Task 4: Laboratory Testing
Task 5: Performance Monitoring and Reporting
Task 6: Instrumentation
Task 7: Determine Pavement Design Criteria
Task 8: Draft Final Report
Task 9: Final Report

Related Contracts/Tasks:
Note any other supporting contracts

Principal Investigator: Bora Cetin, Michigan State University
Technical Liaison:  Raul Velasquez, MnDOT
Project Technical Advisory Committee (TAP)Email the TAP

Terry Beaudry (MN)
John Siekmeier (MN)
Deepak Maskey (CA)
Ed Johnson (MN)
James Bittmann (MN)
Tim Andersen (MN)
Jeff Horsfall (WI)
Richard Endres (MI)
Thomas Fennessey (MO)
Heather Shoup (IL)
Raul Velasquez (MN)

Related Materials

Video of Construction of Test Cells at MnROAD


Final Report:      October 31, 2020