This is a very brief summary. For in depth details on distresses and suggested maintenance procedures see MS-16 Asphalt in Pavement Preservation and Maintenance.

Asphalt Pavement Distress Summary Contents

TYPE OF DISTRESS POSSIBLE CAUSE MAINTENANCE SUGGESTIONS

Fatigue (Alligator) Cracking

Alligator Cracking image
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  1. Excessive loading
  2. Weak surface, base, or subgrade
  3. Thin surface or base
  4. Poor drainage
  5. Any combination of 1-4
Full-depth patch

Block Cracking

Block Cracking image
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  1. Old and dried out mix
  2. Mix was placed too dry
  3. Fine aggregate mix with low penetration asphalt & absorptive aggregates
  4. Aggravated by low traffic volume
Any surface treatment or thin overlay

Edge Cracks

Edge Cracking image
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  1. Lack of lateral support
  2. Settlement of underlying material
  3. Shrinkage of drying out soil
  4. Weak base or subgrade layer
  5. Poor drainage
  6. Frost heave
  7. Heavy traffic or vegetation along edge
Improve drainage. Remove vegetation close to edge. Fill cracks with asphalt emulsion slurry or emulsified asphalt
Crack seal/fill

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TYPE OF DISTRESS POSSIBLE CAUSE MAINTENANCE SUGGESTIONS

Longitudinal (Linear) & Transverse Cracking

Longitudinal Cracking image
Transverse Cracking image
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  1. Poorly constructed paving joint crack
  2. Shrinkage of the asphalt layer
  3. Daily temperature cycling
  4. Cracks in an underlying layer that reflect up through the pavement
  5. Longitudinal segregation caused by the improper operation of the paver
Improve drainage by removing the source that traps the water
Seal crack or fill with asphalt emulsion slurry or light grade of asphalt mixed with fine sand.
Provide side drainage ditches
Crack seal/fill

Reflection Cracking

Reflective Cracking image
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  1. Differential movement between the asphalt and concrete layers
  2. Can deteriorate further under heavy traffic
Crack seal/fill

Slippage Cracks

Slippage Cracking image
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  1. Lack of a good bond between surface layer and the course beneath due to dust, oil, dirt, rubber, water and other non-adhesive material
  2. Tack coat has not been used
  3. Mixture has a high sand content
  4. Vehicular turning or stopping movements in pavements with a low-strength surface mix
Partial or full-depth patch


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TYPE OF DISTRESS POSSIBLE CAUSE MAINTENANCE SUGGESTIONS

Corrugations & Shoving

Corrugations & Shoving image
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  1. Mixtures too high in asphalt
  2. Low air voids
  3. Fine aggregate content too high
  4. Excessive moisture or contamination in the granular base
  5. Smooth or rounded aggregate
  6. Incorrect asphalt grade
Deep or full-depth patch

Rutting

Rutting image
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  1. Consolidation or lateral movement of any of the pavement layers or the subgrade under traffic
  2. Insufficient design thickness
  3. Lack of compaction
  4. Weaknesses in the pavement layers due to moisture infiltration
  5. Weak asphalt mixtures
Cold mill and overlay or thin surface patch

6. Settlement/Grade Depressions

Settlement/Grade Depressions image
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  1. Settlement or failure in the lower pavement layers
  2. Improper construction techniques

Cold mill and overlay
Thin surface patch
Infrared patch


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TYPE OF DISTRESS POSSIBLE CAUSE MAINTENANCE SUGGESTIONS

Upheaval/Swell

Upheaval/Swell image
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  1. Expansive soils (which swell in the presence of moisture)
  2. Frost heave (in which ice lenses grow beneath the pavement, causing the pavement to crack)
Full-depth patch

Utility Cuts/Patch Failure

Utility Cuts/Patch Failure image
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  1. A portion of a pavement has been removed and replaced
  2. A portion of a pavement where additional material has been added
  3. Poor installation techniques such as inadequate compaction, inferior or improper materials
  4. Failure of the surrounding or underlying pavement
Replace patch with deep or full-depth patch

Pot Hole

Pothole image
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  1. Continued deterioration of another type of distress, such as thawing of a frozen subgrade, cracking, raveling, or a failed patch after pieces of the original pavement surface have been dislodged
  2. Poor surface mixtures
  3. Weak spots in the base or subgrade
  4. Severity of the surrounding distress and traffic action accelerate potholes
Partial, full-depth or injection patching


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TYPE OF DISTRESS POSSIBLE CAUSE MAINTENANCE SUGGESTIONS

Raveling/Weathering

Raveling/Weathering image
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  1. Asphalt binder has hardened excessively
  2. Poor-quality mixture
  3. Usually requires the presence of both traffic and water to occur
Any surface treatment or thin overlay

Bleeding

Bleeding image
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  1. Improperly constructed seal coat
  2. Too much asphalt in a mix
  3. Too heavy a prime or bond/tack coat
  4. Excessive sealant in the cracks or joints under an overlay
  5. Traffic can contribute to bleeding if the asphalt layers become overcompacted and excess asphalt is forced to the surface
Chip Seals, Sandwich Seals, thin overlay

Polished Aggregate

Polished Aggregate image
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  1. Soft aggregates that polish quickly under traffic
Any surface treatment except fog seal


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TYPE OF DISTRESS POSSIBLE CAUSE MAINTENANCE SUGGESTIONS

Loss of Aggregate on Surface Treatments

Loss of Aggregate on Surface Treatments image
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  1. Aggregate n ot spread immediately
  2. Asphalt may have cooled to much
  3. Aggregate too dusty or too wet when spread
  4. Not rolled immediately after placing it may not become seated
  5. Steel-wheeled roller alone was used for compaction
  6. Weather too cool when treatment applied
  7. Fast traffic too soon after application

Hot coarse sand spread over affected areas
Rolled immediately after spreading with a pneumatic-tired roller

Longitudinal/Transverse Streaking

Longitudinal/Transverse Streaking image
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  1. Aggregate n ot spread immediately
  2. Improper spray bar height causing incorrect overlap of the spray fans
  3. Changing spray bar height as the distributor load decreases
  4. Nozzle problems (incorrect angle, incorrect size, different sizes, plugged or restricted nozzles, or ones with imperfections)
  5. Nozzle control linkage problem
  6. Inconsistent pump speed or pressure to the nozzles, and varying distributor travel speed
  7. Improper application temperature (allowing the asphalt material to cool); and Improper binder choice (viscosity too high for existing conditions and equipment)
Re-seal surface using proper procedure and adjustment of equipment


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