PAVEMENT MAINTENANCE 1

1
PAVEMENT MAINTENANCE 1

• Part 3 Potholes and Cracks

2
Objectives

• Explore alternatives for repairing potholes,
• Review options for extensive patching,
• Investigate methods and materials for treating
  pavement cracking.

3
HOW A POTHOLE DEVELOPS
4
HOW A POTHOLEDEVELOPS
5
Elements of Successful Pothole Patching

• Use high-quality patching materials, which are
  cost-effective compared to less expensive
  products.
• Place--do not throw--material in the patch area.
• Compact every patch.

6
High Quality Cold Mixes Include

• Carefully selected aggregate types and gradations
• Very clean, durable aggregates
• Very little sand-mixtures are porous
• Polymer modified binder
• Additives that promote adhesion in wet conditions

7
Asphalt Cold Patch Materials

• Standard Spec 00745.00 Asphalt Cold Patch-High
  Performance
• Qualified Products List available describing
  suitable materials

8
Theres a gentleman here to see you about
potholes.
9
Permanent Repairs
10
Dig Out and Repair

• Identify area affected
• Remove to sound material
• Clean, tack edges
• Place patching mixture
• Compact
• Check level

11
Mark Area to be Patched
Mark patch area, extending at least 1 foot
outside of distressed area.
12
Remove Failed Materials
13
(No Transcript)
14
(No Transcript)
15
Place Patching Mixture
16
Spread Mixture Carefully
17
Compact Each Lift Thoroughly
18
Straight-edge the Patch
19
Blown-in Pothole Filler
20
Blown-In Filler
The hole is cleaned with a high volume blower.
A tack coat of asphalt is applied to the area.
A mixture of aggregate and hot asphalt fills the
hole.
A finish coat of aggregate, and traffic flows.
SPRAY INJECTION
21
Patching Rules of Thumb

• Dig out 1 foot beyond the visible cracking
• Dont rock the jackhammer
• Dig out at least 1 1/2 times the thickness of the
  failed AC
• Compaction, compaction, compaction.

22
Questions?
Potholes and Cracks
23
Crack TreatmentsPurpose

• Used to prevent water and debris from entering
  individual cracks in the asphalt pavement
  surface
• Crack treatments are both a corrective and
  preventative maintenance treatment.

24
Crack Sealing
Feasibility
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Cracking Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
Feasible
Not Appropriate
25
Crack Sealing
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Crack Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
26
Crack Repair Guidelines
27
Dont do this!
28
Or this!
29
Proper Crack Sealing Technique
30
For Effective Crack Sealing

• Perform sealing during late fall/early spring
  when cracks are open.
• Sealing does not proceed if rain is imminent.
• Ambient or surface temperature should meet
  manufacturers requirementsusually 40F and
  rising for routing and sealing.
• Use appropriate materials.

31
Preparation is Key!

• Spray the weeds in advance
• Clean the pavement surface.
• Provide for traffic control.
• Clean the crack, removing any moss or grass out
  of crack.
• Dry the crack if necessary. (Hot air lance)
• Fill it with crack seal material.
• Apply something to surface of seal to minimize
  the tackiness.

32
Pavement Preparation

• Cleaning and Drying
• Broom
• Compressed Air
• Sandblasting
• Hot Air Blasting (Heat Lance)

33
Cracks Must Be Clean Dry Use Compressed
Air Note Be Sure Compressor Is Equipped With A
Moisture Trap
34
...Or Clean with a Hot Air Lance

• Up to 3000F
• gt 2000 ft/sec blast velocity
• Propane burner-no flame
• Conducted immediately ahead of sealant
  installation (5 mins or 50 yards max)

• Comments
• For wet conditions, lance can improve performance
• Otherwise, compressed air may be more effective
  (Québec study)

35
Rout and Seal

• Cut the pavement to a prescribed width and depth
• Improves sealant performance
• Better adhesion
• Reduced tensile stress on material

Crafco, Inc
36
Crack Sealing
W
D
Typical Dimensions
W 0.5 to 0.75 D 0.5 to 0.75
37
Traffic Control

• Detour traffic until seal cures
• Cover sealant with sand for quick opening
• Begin filling at pavement centerline

38
Blotting Materials

• Dry sand
• Toilet paper (proven effective in SHRP research!)

39
Crack Seal Materials

• Standard Spec 00746.00 Poured Filler/ Hot Poured
• Qualified Products List available describing
  suitable materials

40
Crack Seal

• The most common product used D1190
• Cost per pound 0.26
• Cost per linear foot to crack seal 0.40
• Should reseal after 5 years?

41
Crack Sealing
42
Crack Sealing Rules of Thumb

• For linear cracks only (not intended form
  alligator cracking)
• Clean cracks with forced air or heat lance
• Dont over-fill crack with sealant avoid surface
  smears
• Sweep up excess sanding

43
Review

• Investigate methods and materials for treating
  pavement cracking,
• Explore alternatives for repairing potholes,
• Review options for extensive patching.

44
Questions?
Potholes and Cracks
45
Small Group Activity

• Identify the distress
• Describe the cause
• Outline the optimum maintenance repair

10 Minutes
46
Photo No. 1
47
Photo No. 2
48
Photo No. 3
49
Photo No. 4
AI 38 Use for Group
50
Photo No. 5
AI 30 Use for Group
51
Photo No. 6
AI 47 Use for Group
52
Photo No. 7
AI 47 Use for Group