Texas Perpetual Pavements - New Design Guidelines (0-4822-P6)

Since 2001, the State of Texas has been designing and constructing perpetual pavements (PPs) on some of its heavily trafficked highways where the expected 20-year truck-traffic estimate of 18 kip ESALs is in excess of 30 million. As of December 2009, 10 PP sections were in service, typically consisting of about 22 inches total thickness of hot-mix asphalt layers and supported on an 8-inch-thick treated (lime or cement) base, resting on a well-compacted subgrade soil. Based on the findings of Project 0-4822, this report provides new guidelines and recommendations for the future design, construction, and performance evaluation of Texas PP structures. The report describes the recommended structural thickness design, design software, response criteria, mix design, and layer moduli values. Recommendations for future PP construction improvements and performance evaluation strategies are also presented in the report.