OAPC Top 10 Lis ist #7 Doubra C. C. Ambaio iowei, i, Ph.D .D., - PowerPoint PPT Presentation

PAVEMENT QUALITY Ach chieving Proper Pavement Density OAPC – Top 10 Lis ist #7 Doubra C. C. Ambaio iowei, i, Ph.D .D., P.E .Eng., MCSCE Tech echnical Di Director Ontario Asphalt Pavement t Co Council l (Co (Council of of ORBA) De December 5, , 2019

PRESENTATION OUTLINE o RECAP: OAPC’s Top 10 List – Ways to Get More Durable HMA Pavements o COMPACTION – The Fundamentals o The FACTS: ❖ Understanding Material Properties ❖ Placement and Rolling Operations ❖ Permeability and Lift Thickness ❖ Stable Support ❖ Transport Logistics and Environmental Factors ❖ Role of Specifications ❖ Employ Innovative Technologies ❖ Communication, Preparation and Planning o CONCLUSION o REMINDER

RECAP – OAPC’s Top 10 Lists ❑ Ways to Get More Durable HMA Pavements

COMPACTION – The Fundamentals ❑ Reducing Volume, Increasing and Controlling Density ❑ Reasons for Compaction ➢ To prevent further compaction ➢ To provide shear strength or resistance to rutting ➢ To ensure the mixture is waterproof ➢ To prevent excessive oxidation of the asphalt binder Good Compaction Leads to Good Performance

THE FACTS – The Fundamentals ❑ Durability vs Air Voids Stability Cohesion Zone of Highest Durability Flushing Raveling 0 % Air Voids

THE FACTS - Understandin ing Material l Propertie ies ❑ Workability, Mix Stiffness and Compactability Causes Effects ➢ Large Maximum-sized Particles ➢ Rough Surface, Difficulty to Place ➢ Excessive Coarse Aggregate ➢ May be Hard to Compact ➢ Too Low a Mix Temperature ➢ Uncoated Aggregate, not Durable, Rough Surface, Hard to compact ➢ Mix Shoves Under Roller, Remains ➢ Too Much Medium-sized Sand Tender ➢ Low Mineral Filler Content ➢ Tender Mix, Highly Permeable ➢ High Mineral Filler Content ➢ Mix May be Dry or Gummy, Hard to Handle, not Durable

THE FACTS - Understandin ing Material l Propertie ies ❑ Asphalt Binder: Rheology and Temperature Susceptibility ❑ Maintaining Mix Stability ❑ Compactive Effort

THE FACTS – Pla lacement and Roll llin ing Operations ONE OF THE ESSENTIALS FOR A CONSISTENT AND HIGH QUALITY HOT MIX ASPHALT PAVEMENT IS TO PROVIDE FOR A CONTINUOUS OPERATION

THE FACTS – Pla lacement and Roll llin ing Operations ❑ Right equipment, well maintain ❑ At or above compaction temperatures behind screed ❑ Uniform and Consistent ❑ Watch for Segregation

THE FACTS – Pla lacement and Roll llin ing Operations ❑ Rolling Practices and Procedures ➢ Production Rate ➢ Roller Width, Type and Speed ➢ Rolling Pattern – Quality Control Testing ➢ Mix Type ➢ Mix Thickness ➢ Temperature Temperature is Critical

THE FACTS – Permeabili lity and Lif ift Thic ickness ❑ Lift thickness impacts on the rate at which the mat cools and on permeability of the mix. Phases of Voids within a HMA Pavement

THE FACTS – Stable Support ❑ Pavements Built on Substandard Foundation will Prematurely fail. ❑ Investments in Intelligent Compaction Technologies may be Worthwhile. ❑ Proper Use and Application of Tack Coat is Vital to Ensure Good Bonding between the MAT and Underlying Structural layers.

THE FACTS – Transport Logis istic ics and Envir ironmental l F Factors ❑ Considerations for Materials and Mix Transportaion ❑ Environmental Factors Affecting Cooling Rate of the Mat ❑ Environmental Factors out of Contractors Control

THE FACTS – Role of f Specifications ❑ Good Specifications Play an Important Role in Achieving the Required Pavement Density. ❑ Ensure Proper Inspection and Enforcement of Compaction Specifications. ❑ Implement Fair Material and Construction Performance Incentive/Disincentives.

THE FACTS – Employ In Innovative Technolo logies ❑ Encourage Use of Innovative Technologies ❑ Longitudinal Joint Construction - Incorporating Joint Heaters/Paving in Echelon

THE FACTS – Communication, Preparation & Pla lanning Quality HMA Pavements are ALWAYS the Result of TRAINING and TEAMWORK

THE FACTS – Communication, Preparation & Pla lanning ❑ Pre-Paving Conference is Critical for Success JMF ✓ Establish Communications ✓ Acquaint Each Other with the Job Expectations ✓ Discuss Any Special Considerations

CONCLUSION ❑ Good Paving Practices Focus on UNIFORMITY and BALANCE ANYTHING AND EVERYTHING THAT COULD IMPACT ON THE DURABILITY AND STABILITY OF THE MIX, SHOULD BE CONSIDERED.

REMINDER ❑ FACTSHEET #7 – PROVIDE PROPER PAVEMENT DENSITY WWW.ONASPHALT.ORG

THANK YOU!