Implementation of Very Thin Overlay (<1 inch) in the Lufkin District

Project Description

Texas Department of Transportation engineers selected a section of U.S. Highway 59 in Lufkin for testing the new Crack Attenuating Mixes (CAM) developed through this research project. BUS 59 in Lufkin is a heavily-traveled four-lane highway with existing jointed concrete and an existing Hot Mix Asphalt (HMA) surface which was badly cracked and in continuing need of maintenance. The mixes were designed and completed based on TxDOT¿s SS 3109 specification, using a top-quality granite aggregate, an 8.3 asphalt content and a PG76-22 binder. The mix was designed to strike a balance of both rut resistance and cracking resistance. Researchers tested the roadway with both Ground Penetrating Radar (GPR) and the Rolling Dynamic Deflectometer (RDD), and noted that the roadway performance had been good since the application of the thin overlay a year before. At the same time, they noted that relatively low skid values presented one area of concern. Recommendations for future applications included: reduce the asphalt binder content from 8.3 to 7.5 if PG76-22 binder is used, and avoid the use of PG70-22 binder when this CAM design is used.

Project Publications

Design, Construction, and Performance Monitoring of the Very Thin Overlay Placed on Bus 59 in the Lufkin District 5-5598-01-2

Balanced Mix Design Report for Lufkin's Crack Attenuating Mix (CAM) 5-5598-01-1

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