Two-Lift Paving - Introduction
2 likes969 views
The document provides an overview of two-lift paving, detailing its history in the U.S., advantages, and barriers to implementation. It highlights the benefits of using two wet-on-wet layers of concrete, including improved life cycle costs and environmental impact. The paper also addresses challenges such as the need for specialized equipment and specifications, suggesting that further adoption requires overcoming fears and learning curves associated with the technique.
Two-Lift Paving - Introduction
- 1. Two Lift Paving An Overview Dr Peter Taylor With thanks to: Jim Grove FHWA
- 2. Two-Lift Paving • What is it? • History in the US • Advantages • Barriers • Where next?
- 3. What is it? • Placement of two wet-on-wet layers of concrete
- 4. History • Concept is not new Blome Granitoid
- 5. History • Europeans learned it from us • We learned it again from them in 1992 and 2006
- 6. History • FL 1977 US41 • MI 1993 I75 • KS 1997 Hwy 96 • FL 2001 • KS 2008 I70 • MnRoad 2010 • MO 2011 SH141
- 7. Benefits • Lower impact system below • High–end system above • Improved life cycle cost • Improved environmental impact
- 8. Benefits • Lower level Aggregates not suitable for surface: Polishing Local!
- 9. Benefits • Lower level Recycled materials High SCM contents Lower environmental impact
- 10. Benefits • Lower level Strong enough for structural purposes – but no more ~600 psi flex Not necessarily durable
- 11. Benefits • Upper level Exposed aggregate finish Quiet Good friction
- 12. Benefits • Upper level Special materials TiO2 High durability mix Strength likely higher than needed
- 13. Barriers • Two paving trains • Batching control
- 14. Barriers • Cost Reportedly initial cost increment can be small LCCA indicates savings • Specifications IL Tollway • Experience There is a learning curve
- 15. Where next? • It is common in Europe • Have to address: Fear The learning curve Specifications