Ultra Thin Bonded
Wearing Coarse
Sponsored by:
Minnesota LTAP Center
Presented by:
Michael Marti, P.E.
SRF Consulting Group, Inc.
Dan Wegman, P.E.
SemMaterials
A little history. . .
•
•
•
•
•
1988 - First Trial in France
1992 - Introduced in U.S
1992 - Jobs in TX & AL
1993 - Jobs in NJ & PA
1999 - Jobs in MN
Ultra Thin Bonded Wearing Coarse
What is it?
• Surface Treatment
– Preventive Maintenance
– Corrective Maintenance (Surface Rehabilitation)
• Single Pass System
– Emulsion membrane
– Thin gap-graded hot mix
– Placed with Special Equipment
Ultra Thin Bonded Wearing Coarse
Machine Specially Engineered
3 Processes
Spray Novabond
Lay Hot Mix
Smooth the Mat
Application of
HMA
Application of
membrane
Ultra Thin Bonded Wearing Coarse:
The Process
The Novabond Cures, Bonding
the HMA to the Pavement
Total 9/16”
Depth of Mix
3/8” Agg
Size
Surface of Mix
Coating
on mix
3/16”
Membrane
Existing Pavement
Polymer Modified Membrane
• Sprays easily
• Cures quickly
• Superior bonding
Ultra Thin Bonded Wearing Coarse
HMA
• High quality aggregate
– Restores & retains friction
• Gap-graded
– Reduces noise
– Reduces backspray
• Mix designed specially for process
Ultra Thin Bonded Wearing Coarse
Binder
• Polymer modified binder
–
–
–
–
–
–
Less draindown
More forgiving (less sensitive to temp, etc.)
Quicker traffic return
Sticks better, less water sensitivity
Better cracking resistance
More durable
Application rates
• Emulsion membrane
– 0.15 - 0.3 gal/yd2
• Ultra-thin hot mix asphalt overlay
– Type A - 45-55 #/yd2
– Type B - 50-65 #/yd2
– Type C - 55-80+ #/yd2
• Total thickness: 3/8 to 3/4”
Rolling & Return to Traffic
• Rolling only to seat aggregate
• Return to traffic in 10-20 minutes
Ultra Thin Bonded Wearing Coarse
Construction Advantages
• Quick to apply
• Reopens to traffic quickly
• Cost effective
Performance
•
•
•
•
•
•
•
Resists wear & rutting
High skid resistance
Reduced tire splash, hydroplaning
Reduced tire noise
Seals out water
No loose aggregate
Thinner lift
– reduces applied weights
– overhead clearance, curb reveal & drainage profiles
– maximizes use of expensive aggregates
Reduced Backspray
Wisconsin project - 5000 ADT
Backspray from
dense graded surface
Greater visibility on Ultra
Thin Bonded Wearing
Coarse surface