Resilient Modulus Strength of Base Course with Recycled Bituminous Material

Principal Investigator:

Joseph Labuz, Professor & Department Head, Civil, Environmental and Geo-Engineering

Co-Investigators:

  • Andrew Drescher, Professor, Civil, Environmental and Geo-Engineering
  • Bojan Guzina, Associate Professor, Civil, Environmental and Geo-Engineering

Project Summary:

Full-depth reclamation has been proposed as a viable alternative in road construction, where material and transportation costs are reduced because recycling reduces the need for hauling new material and disposing of old material. Recycled asphalt pavement (RAP) material, sometimes called a salvaged bituminous mixture, may be used either alone or in combination with other aggregate materials in the production of the base course. This project is concerned only with the base material produced from full-depth reclamation.

The objective of this research project was to determine the strength and deformation characteristics of base material produced from RAP and aggregate. Researchers performed both field and laboratory measurements of resilient modulus for three reconstructed roads that used recycled asphalt paving material in the pavement base, and also performed modulus, shear strength, and deformation tests on reclaimed aggregate base and recycled asphalt mixed at various ratios.

The specimens with RAP exhibited at least two times greater permanent deformation than the 100% aggregate material. As %RAP increased, more permanent deformation occurred. In summary, the base material produced with various %RAP content performed at a similar level to 100% aggregate in terms of MR and strength when properly compacted. This established procedures and generated necessary inputs for Mn/DOT's pavement design manual. (This is related to research report 2007-05).

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