Two Lift Paving An Overview
Dr Peter Taylor
With thanks to:Jim Grove FHWA
Two-Lift Paving
• What is it?• History in the US• Advantages• Barriers• Where next?
What is it?• Placement of two wet-on-wet layers
of concrete
History• Concept is not newBlome Granitoid
History• Europeans learned it from us • We learned it again from them in
1992 and 2006
History• FL 1977 US41• MI 1993 I75• KS 1997 Hwy 96• FL 2001• KS 2008 I70• MnRoad 2010• MO 2011 SH141
Benefits
• Lower impact system below• High–end system above• Improved life cycle cost• Improved environmental
impact
Benefits
• Lower levelAggregates not suitable for
surface:Polishing
Local!
Benefits
• Lower levelRecycled materialsHigh SCM contents
Lower environmental impact
Benefits
• Lower levelStrong enough for structural
purposes – but no more~600 psi flexNot necessarily durable
Benefits
• Upper levelExposed aggregate finishQuietGood friction
Benefits
• Upper levelSpecial materialsTiO2
High durability mixStrength likely higher than
needed
Barriers
• Two paving trains• Batching control
Barriers
• CostReportedly initial cost increment
can be smallLCCA indicates savings
• SpecificationsIL Tollway
• ExperienceThere is a learning curve
Where next?
• It is common in Europe• Have to address:Fear The learning curveSpecifications
