1. Pavement Preservation Techniques Used in Virginia
Mike C. Dudley
Director of Technical Services
Virginia Asphalt Association

2. What Is Pavement Preservation?
“a program employing a network level, long-term strategy that enhances pavement performance by using an integrated, cost-effective set of practices that extend pavement life, improve safety and meet motorist expectations." 
Source: FHWA Pavement Preservation Expert Task Group
Pavement Preservation offers different techniques that provide several benefits for the roadway, It must be understood that these treatments do not provide any real structural contribution for the pavement but they can improve surface friction, decrease the pavement permeability, and extend the pavement surface life in a cost effective manner.

3. Components of Pavement Preservation?
Proactive
Minor Rehabilitation
Preventative Maintenance
Routine Maintenance

4. What Techniques Are Used?
Traditional Approaches
Emerging Approaches
Chip Seals
Slurry Seal
Microsurfacing
Crack Sealing
Cape Seals
Fiber Modified Microsurfacing
Fibermat
THMACO
SM-4.75

5. Chip Seals Types In VDOT Specs
Surface Seal
Modified Single Seal
Modified Double Seal
Commonly used on low- volume secondary roads and sub-divisions
Surface Seal – Is one application of asphalt material or emulsion and one application of cover aggregate.
Modified Single Seal – Is two applications of asphalt emulsion with one application of cover aggregate and one application of blot fine aggregate
Modified Double Seal – Is three applications of asphalt material or emulsion with two applications of cover aggregate and one application of blot fine aggregate

6. Slurry Seals Types in VDOT Specs
Type A
Type B
Type C
Predominately used on lower volume primary and secondary routes
Type used is function of traffic levels
Type A: Has a very fine gradation of crushed aggregate which has a relativity smooth finish.
Type B: Has a more versatile gradation and is sometimes used in double lift applications.
Type C: Has the most aggressive or coarse gradation, high skid numbers, and thicker lift.

7. Latex Modified Emulsion Treatment or Mircosurfacing
Types in VDOT Specs
Type B
Type C
Predominately used on higher volume routes including interstates
Latex modifier and emulsifiers are milled into the asphalt emulsion.
Typically additives are used to control the set time which is much quicker than a typical Slurry Seal
Type C has a coarser gradation and can be used for rut-filling.

8. Crack Sealing Types in VDOT Specs Used alone or with overlay Type A
Type B
Type C
Used alone or with overlay
Type A – combination of asphalt binder and up to 25% crumb rubber
Type B – made from PG 64H-22 and up to 5% polyester fibers
Type C – material same as Type B except installation requires routing

9. Cape Seals
Combination of a Chip Seal foundation and Slurry Seal surface
Normally used on higher volume primary and secondary routes
Provides a better riding surface and a more aesthetic appearance. This treatment have grown in popularity in VA in the last few years.

10. Fiber Modified Microsurfacing
Similar process as traditional micro- surfacing
Combines polyester fibers in the micro- surfacing process
Used on selected routes to combat cracking

11. Fibermat Similar to Chip Seal process
Introduces a fiber material interlayer between tack coat and chips
Normally overlaid like a Cape Seal with another asphalt-based material
Fiber is applied with the distributor by blowing the fiber into the fresh emulsion prior to applying the chip. The fiber adds a layer of reinforcement that standard chip seals don’t have.

12. THMACO Asphalt concrete material
Similar to fine SMA, but with smaller percentage of fines
Laid at 1” or less
Used on existing concrete and asphalt surfaces
Typically on higher volume routes and interstates
A lot of times THMACO is applied to a concrete pavement prior to adding a asphalt overlay to help reduce reflective cracking.

13. SM-4.75 Asphalt concrete material Laid at 0.75” – 1.25”
Been used on sub-division streets, secondary and primary routes
Installed with traditional paving equipment and provides and excellent riding surface and the traveling public loves the aesthetics.

14. Why Do We Care About Preservation?
VDOT spending increasing amounts on pavement preservation
Important to be good stewards of our transportation system
Preservation system is part of VDOT’s pavement management plan
State and federal dollars are used to fund many projects
Different Pavement Preservation options provide more tools and alternatives for the industry to improve our pavements.

15. VDOT Spending Over Time
Year
Chips Seals
Slurry/Micro
2012
$21,400,000
$32,400,000
2013
$37,000,000
$38,000,000
2014
$28,000,000
$37,800,000
2015
$37,700,000
$44,700,000
2016
$28,700,000
$28,400,000

16. What Are The Inspection Points and Reminders?
Turn it over to Todd Rorrer from VDOT.

17. Questions