Assessment of LADOTD’s Friction Aggregate Source Variations through Laboratory and Accelerated Testing

The research objectives are to assess the PSV test variation through varying of coarse aggregate quarry source, shipment time, and test operator; to propose a new aggregate friction testing procedure for the Louisiana Department of Transportation and Development (LADOTD), which can be used for initial source approval as well as for predicting field friction performance of aggregates used in a wearing course mixture; to determine threshold friction design values (i.e. DFT and mean profile/texture depth values) for commonly-used wearing course mixtures in Louisiana; to validate and update the harmonization correlations obtained in the Louisiana Transportation Research Center (LTRC) Project 12-5P between different pavement friction and texture testing devices, different types of test tires (ribbed and smooth), and at different testing speeds for typical Louisiana asphalt pavements; and to validate and update the relationship between Skid Number (SN) and International Friction Index (IFI) developed in LTRC Project 09-2B through both laboratory and field testing programs.