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

• f ORBA)

De December 5, , 2019

• RECAP: OAPC’s Top 10 List – Ways to Get More Durable HMA

Pavements

• COMPACTION – The Fundamentals
• 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

• CONCLUSION
• REMINDER

PRESENTATION OUTLINE

RECAP – OAPC’s Top 10 Lists

❑ Ways to Get More Durable HMA Pavements

COMPACTION – The Fundamentals

❑ Reducing Volume, Increasing and Controlling Density

Good Compaction Leads to Good Performance

❑ 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

THE FACTS – The Fundamentals

❑ Durability vs Air Voids % Air Voids

Cohesion

Zone of Highest Durability Flushing Raveling

Stability

THE FACTS - Understandin ing Material l Propertie ies

❑ Workability, Mix Stiffness and Compactability

➢ Large Maximum-sized Particles ➢ Excessive Coarse Aggregate ➢ Too Low a Mix Temperature ➢ Too Much Medium-sized Sand ➢ Low Mineral Filler Content ➢ High Mineral Filler Content ➢ Rough Surface, Difficulty to Place ➢ May be Hard to Compact ➢ Uncoated Aggregate, not Durable, Rough Surface, Hard to compact ➢ Mix Shoves Under Roller, Remains Tender ➢ Tender Mix, Highly Permeable ➢ Mix May be Dry or Gummy, Hard to Handle, not Durable

Causes Effects

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 ✓Establish Communications ✓Acquaint Each Other with the Job Expectations ✓Discuss Any Special Considerations

JMF

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!