As the saying goes, Good roads cost money, and bad roads cost more. Hear the latest from the world of pavement preservation and how preservation strategies can stretch tight road maintenance dollars, as well as when maintenance becomes rehabilitation.

1. Pavement Preservation
CALIFORNIA ASPHALT
PAVEMENT ASSOCIATION
FALL ASPHALT PAVEMENT
CONFERENCE
SACRAMENTO, CA
October 29 – 30, 2014
Hans Ho, PhD
Technical Director
(Retired)

2.  Sum of all activities to provide
and maintain serviceable
roadways
 Includes
 Corrective & Preventive
Maintenance
 Minor rehabilitation
 Does not include
 Reactive maintenance
 Major rehabilitation or
reconstruction
10/31/2014 2

3.  Cost effectiveness
 Energy savings
 Reduced emissions
 Reduced user costs
 Life extension
 User satisfaction
 Safety
10/31/2014 3

5. Right Treatment
Right Pavement
Right Time
“

6. How do I get the decision
makers to understand that
“worst first” does not work?

7. Pavement Preservation - Concept
Preventive
Trigger
Condition
(or $
needed) Rehabilitation
Time or Traffic
Trigger
Original Pavement
Optimal Timing
$1
$30-$40

8. ASSUMPTION:
 You own 300 lane miles of road &
 Have a budget of $1.5M for:
• pavement reconstruction
• rehab
• maintenance
• Typical Breakdown
• $1M for reconstruction and rehab =“worst
first” scenario &
• $500K for maintenance

9.  Reconstruction ~ $25.00 per yd2
• (6” mill and fill with HMA @ $75/ton)
• $1M÷$25/yd2 = 40K yd2 or 5.7 LM
Cost of maintenance ~ $4 per yd2
• $500K÷$4/yd2 = 125K yd2 or 17.8 LM
Total LN Mi repaired is 23.5
For 300 lane miles, road cycle will be ~13 years

10.  Costs of reconstruction ~ $25.00 per yd2
 $500K÷$25/yd2 = 20K yd2 = 2.8 LN Mi
 Cost of maintenance ~ $4.00 per yd2
 $1M÷$4/yd2 = 250K yd2 = 35.5 LN Mi
 Total LN Mi repaired ~ 38
 For 300 lane miles, road cycle will be ~ 8 years

11. • Management Support
• Public understanding and
acceptance
• Dedicated & Continuous
Funding
• Good products and
workmanship
• Contractor relationship
• In house training

13.  Fog & Rejuvenating Seals ~$0.50 - $0.75/yd2
 GME – Gilsonite Modified Emulsion ~$0.95/yd2
 Chip Seals
 Cold Applied-
▪ PMCRS-2h ~$1.75/yd2
▪ PMRE ~$2.00/yd2
 Hot Applied –
▪ Asphalt Rubber ~$2.75 - $3 /yd2
▪ Terminal Blends ~$2.50 - $2.75/yd2
 Slurry Seals ~$1.50/yd2
 Micro-Surfacing ~$1.75/yd2
 Bonded Wearing Course ~$9- $10/yd2

14.  Benefits:
• Renews aged asphalt pavements
• Seal small voids and surface cracks
• Improve lane delineation and pavement marking
• Prevent raveling of loose aggregate with chip seals
• Prevents water penetration
 Material:
• SS-1h
• CSS-1h
• CQS-1h
• PMRE
• Gilsonite Modified Emulsion
Material need to be diluted

15.  Light application of diluted slow-setting
asphalt emulsion
 Common uses
 Seal aged surface
 Improve lane delineation
 Typical treatment life: 1 to 3 years

16. Heavily aged,
dense-graded HMA
Open-graded HMA

17. Fog seal over existing chip seal

19. 1. Asphalt – PG graded asphalt
2. Rejuvenator -Acts to penetrate and add
additional maltenes to the asphalt matrix to
restore flexibility to the binder. Good
aggregates don't wear out as fast as asphalt
becomes brittle
3. Gilsonite – Mined asphalt. Acts as a modifier
to increase the polar content to form a film
thickness that no other product can match.

20.  Reduces raveling, by locking in fines in mat.
 Blacker surface for better line delineation
 allows us to use blast furnace slag to help
restore the loss of minor fines and improve
the skid numbers.
 Department of Defense only uses Gilsonite
Modified Emulsion to reduce (FOD) Foreign
Object Debris (Proprietary product known as
GSB-88)

22.  Application rate: 0.45 to 0.70 l/m2 (0.10 to
0.15 gal/yd2)
 Spray temperature range: 20 to 70 °C (70 to
160 °F)

23. Spray Bar and Nozzles
Single Overlap hh
RoDaoduwbaley OSuvrefralacep
RoaTdrwipaley OSuvrefralacep
Roadway Surface
h

24. BAD…

25. Equipment inspection
Good

26.  Using excess emulsion for
the existing pavement
surface
 Placing in wet and/or cool
weather
 Over or under dilution
 Incompatible water for
dilution
 Skid issues
10/31/2014 26

27. Chip Seals
 Chip seals consist of asphalt emulsions, asphalt rubber
binder or terminal blend binder followed by a single layer
of aggregate.
 Chip seals can consist of multiple layers (single and
double chip seals), and are typically followed with a fog
seal. Chip seals can also be covered with a slurry or
microsurfacing thereby creating a “cape seal”.
 Typical Treatment life: 5 – 7 years

28. Chip Seals
Benefits:
• Renews aged asphalt pavements
• Improves surface friction course
(skid resistance)
• Seals small voids and surface cracks
• Improves lane delineation and pavement marking
• Prevents raveling of loose
aggregate with chip seals
• Prevents water penetration

29. Polymer Modified Emulsion Chip Seal
 PMCRS-2h
 Scrub Seals PMRE (Rejuvenating Chip Seals)
 Usually .25-.40 gal/yd2 binder
Hot Applied Chip Seal
 Asphalt Rubber Chip Seal
 Terminal Blend (Modified Binder Chip Seal)
 Usually .35-.6 gal/yd2 binder
Chip over Paving Fabric
 .25-.35 gal/yd2 binder plus chip seal over top

30. Step 4 Construction Inspection
Roll
Chip
Spray
Sweep
Sweep Again

31.  Start/Stop Application on Building Paper
 Chipper Within 100’ of Distributer
 Chipper Speed =NO rolling Chips
 Application Appears Uniform
 Rollers Tight to Chipper, Speed 7mph
max
Chipper always within
100 feet of Distributer
NOTE DISTANCE

32. Poor Workmanship

33. Inadequate/Uneven Aggregate Coverage or Precoating Issues

35.  Polymer Modified Rejuvenating Emulsion
 Broom scrubs material in
 Emulsion + Broom = the ability to eliminate
crack filling = cost savings.

36. SCRUB AND SAND SEALS
Scrub Seals using sand or aggregate:
• PMRE asphalt emulsion
• Sand or aggregate
• Broom is dragged behind the distributor
truck to embed the emulsion into the cracks
• On sand seals, pneumatic tired rollers
embed the sand into the emulsion

37. SCRUB SEALS
Emulsion Wave

38. Asphalt Rubber Terminal Blends

39. Chip over Paving Fabric
• Low volume roads
• Good seal due to high asphalt content
•.28-.35 gal/yd2 of asphalt followed by chip seal with .3-.5 gal/yd2
of emulsion or hot applied binder
• Flexible solution for a flexible road!

40. Fabric ready for chip
RAC/Sami 10 Years old “Ventura” warranty project
10 year old “Ventura” ARCS
Nothing done
Cape Seal
Terminal Blend Chip Seal

42.  Improper surface
preparation
 Applying in cool and/or
wet weather
 Using dirty rock
 Not accounting for new
patches or flushed
surfaces
 Not taking traffic into
account
 Over spreading or under
spreading binder or
aggregate
10/31/2014 42

44. Slurry Sealing
Benefits:
• Improved surface friction course (skid resistance)
• Seals small voids and surface cracks
• Improves lane delineation and pavement marking
• Prevents water penetration
•Typical Treatment Life: 5 – 7 years
• Can be part of a “cape seal”
(slurry seal over a chip seal)

45. - Laid at one-stone thickness
- Largest stone bears traffic load
Existing road surface
1/4 - 3/8”

46. Micro-Surfacing
Benefits:
• Chemically driven emulsion which can reduce traffic delays to
less than 1 hour
• Improved surface friction course (skid resistance)
• Seals small voids and surface cracks
• Improves lane delineation and pavement marking
• Day or night construction
• Rut filling and re-profiling
• Prevents water penetration
•Typical Treatment life: 8 – 12 years
•Can be part of a “cape seal”
(slurry seal over a chip seal)

47. - Applied in multi-stone thickness
- Stone interlock and modified binder bears traffic load
- May be applied in multiple layers
Existing road surface
3/8” +
3/8” +

48. BAD
GOOD
GOOD

50.  Improper surface preparation or placing on
badly cracked pavements
 Not following the mix design
 Construction in wet weather
 Equipment not calibrated
 Poor workmanship, including too much water
in the mix
 Insufficient applications rate
 Inadequate QC and acceptance testing
50

52. What is Bonded Wearing Course
 Part Chip Seal
 Application of .13-.25 gal/SY of a polymer
modified emulsion for adhesion
 Part HMA Overlay
 Use of gap or open graded, polymer or
rubberized HMA to finish the process
Typical Treatment Life: 8 – 12 years

53. Bonded Wearing Course
 From the chip seal
 Spray application that
seals the existing
roadway
 Bonding of the new
surface to the old surface
 Quick process – up to
50,000 SY per day
 From the HMA
overlay
 Improved ride quality
 Quick return to traffic
 No sweeping or fog
seal needed

54. HMA
Emulsion
Joint Matching
Device

55. The emulsion membrane “wicks up”
around the HMA aggregates
9-12 mm
coating on
aggregates
Existing Pavement
5/8”
minimum
Depth of Mix
3/16”
Emulsion
membrane
depth
The emulsion cures,
bonding the mix & pavement
3/8”
Nominal
Ag Size

56.  Tack Coat Application
Rate:
 0.14 – 0.25 gal/yd2
 Lift Thickness:
 ¾” – 1”
 Compaction:
 Method – 2 passes with a
minimum of two rollers in
static mode

58. Machine is designed to reduce thermal
and mechanical segregation

59. NY-191326.351/010103YvashHR1

61.  Since 1998 in California
 First project – Lark Ellen
Blvd, Los Angeles County
 Since 2002 for Caltrans
 Hwy 50 over Echo Summit,
Lake Tahoe

62. MTC Demo
Project- Before
Madison from 7th
to 8th Streets
City of Oakland
Bonded
Wearing
Course –
As of
March Applied 26, 2013
2003

64.  California Chip Seal Association
www.chipseal.org
Pavement Preservation
Workshop, February, 2015
hosted by the California Chip
Seal Association

65. Thank you
www.telfercompanies.com
Hans Ho, PhD
Technical Director (Retired)
hansho@telfercompanies.com
(925) 228-1515 X1329