PAVEMENT MAINTENANCE 1 Part 3: Potholes and Cracks Idaho Roads Scholar Program.
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Transcript of PAVEMENT MAINTENANCE 1 Part 3: Potholes and Cracks Idaho Roads Scholar Program.
PAVEMENT MAINTENANCE 1Part 3: Potholes and Cracks
Idaho Roads Scholar Program
Objectives Explore alternatives for repairing
potholes, Review options for extensive patching, Investigate methods and materials for
treating pavement cracking.
HOW A POTHOLE DEVELOPS
HOW A POTHOLEDEVELOPS
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.
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
Asphalt Cold Patch Materials
Standard Spec 00745.00 Asphalt Cold Patch-High Performance
Qualified Products List available describing suitable materials
““There’s a gentleman here to see you about potholes.”There’s a gentleman here to see you about potholes.”
Permanent Repairs
Dig Out and Repair
Identify area affected Remove to sound material Clean, tack edges Place patching mixture Compact Check level
Mark Area to be Patched
Mark patch area, extending at least 1 foot outside of distressed area.
Remove Failed Materials
Place Patching Mixture
Spread Mixture Carefully
Compact Each Lift Thoroughly
Straight-edge the Patch
Blown-in Pothole Filler
Blown-In Filler
SPRAY INJECTION
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.
Patching Rules of Thumb
Dig out 1 foot beyond the visible cracking
Don’t rock the jackhammer Dig out at least 1 1/2 times the
thickness of the failed AC Compaction, compaction,
compaction.
Questions?
Potholes
and Cracks
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.
Crack Sealing
Distress TypeFatigue Cracking
Linear & Block Cracking“Stable” Rutting
RavelingFlushing/Bleeding
RoughnessFriction Loss
Moisture DamageShoving
Extent of ProblemMinor Major
FeasibleNot Appropriate
FeasibilityFeasibility
Crack Sealing
Distress Type
Fatigue CrackingLinear & Block Crack
“Stable” RuttingRaveling
Flushing/BleedingRoughness
Friction LossMoisture Damage
Shoving
Extent of ProblemMinor Major
EffectiveMarginal
No Impact
Effectiveness
Crack Repair Guidelines
Filling (sand or sand-emulsion slurry)
Patching (cut and replace material)
> 3 /4 inch (19 mm)
Crack Fill (short life, prep for resurfacing)
Crack Seal (> 5 yr life)
1/8 – 3/4 inch(3 – 19 mm)
Do nothing Fog seal
Surface treatment (chip seal, slurry, etc.)
< 1/8 inch (3 mm), non-working
Treatment OptionsCrack Width
Don’t do this!
Or this!
Proper Crack Sealing Technique
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
manufacturer’s requirements—usually 40F and rising for routing and sealing.
Use appropriate materials.
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.
Pavement Preparation Cleaning and Drying
Broom Compressed Air Sandblasting Hot Air Blasting (Heat Lance)
Cracks Must Be Clean & DryCracks Must Be Clean & DryUse Compressed AirUse Compressed Air
Note: Be Sure Compressor Is Equipped With A Note: Be Sure Compressor Is Equipped With A Moisture TrapMoisture Trap
...Or Clean with a Hot Air Lance
Up to 3000°F
> 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)
Rout and Seal
Cut the pavement to a prescribed width and depth
Improves sealant performance Better adhesion Reduced tensile
stress on material
Crafco, Inc
W
D
W = 0.5” to 0.75”W = 0.5” to 0.75”D = 0.5” to 0.75”D = 0.5” to 0.75”
Typical Dimensions:Typical Dimensions:
Crack SealingCrack Sealing
Traffic Control
Detour traffic until seal cures Cover sealant with sand for quick
opening Begin filling at pavement centerline
Blotting Materials
Dry sand Toilet paper (proven effective
in SHRP research!)
Crack Seal Materials
Standard Spec 00746.00 Poured Filler/ Hot Poured
Qualified Products List available describing suitable materials
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?
Crack Sealing
Crack Sealing Rules of Thumb
For linear cracks only (not intended form alligator cracking)
Clean cracks with forced air or heat lance
Don’t over-fill crack with sealant; avoid surface smears
Sweep up excess sanding
Review Investigate methods and materials for
treating pavement cracking, Explore alternatives for repairing
potholes, Review options for extensive patching.
Questions?
Potholes
and Cracks
Small Group Activity
Identify the distress Describe the cause Outline the optimum maintenance
repair
10 Minutes
Photo No. 1:Photo No. 1:
Photo No. 2:Photo No. 2:
Photo No. 3:Photo No. 3:
AI 38: Use AI 38: Use for Group Group
Photo No. 4:Photo No. 4:
AI 30: Use AI 30: Use for Group Group
Photo No. 5:Photo No. 5:
AI 47: Use AI 47: Use for Group Group
Photo No. 6:Photo No. 6:
AI 47: Use AI 47: Use for Group Group
Photo No. 7:Photo No. 7: