Missouri lab Research on Tear-Off Shingle Scrap

The Missouri Department of Transportation (MoDOT) has a new shingles recycling specification that was originally released in early 2005. Pace Construction is the primary HMA producer that is utilizing tear-off RAS in their paving products. Peerless Resource Recovery and Landfill is the recyclers responsible for receiving the mixed roofing material, sorting, grinding and screening the material in a product suitable for Pace Construction's HMA plant.

A Missouri project provided the necessary similar and additional lab data to further analyze the hot-mix asphalt (HMA) supplemented with recycled asphalt shingles (RAS) produced from tear-off shingle scrap.  The RAS – derived HMA test samples were compared to control samples of HMA produced from 20% RAP, 0% RAS mixes.  The University of Minnesota, Department of Civil Engineering, is already scheduled to perform similar lab analysis using its equipment to measure indirect tensile strength for the Minnesota Department of Transportation.  The project will result in verification or modification of requirements within the new draft MoDOT specification on tear-off shingle recycling into HMA.  This project will conduct additional empirical lab tests needed by MoDOT engineers in order to confirm requirements within their new draft specification allowing recycled tear-off shingles in HMA.

MoDOT is conducting a lab analyses project similar to the Minnesota OEA study.  MoDOT intends to produce additional lab data to further analyze the HMA supplemented with tear-off RAS.  The University of Minnesota Department of Civil Engineering has performed similar lab analyses using its equipment to measure indirect tensile strength for as part of a cooperative study with the Minnesota Department of Transportation.

For more information please contact Joe Schroer, PE at: joe.schroer@modot.mo.gov