Comal County Chip Sealing

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Comal County Chip Sealing
June 26, 2007
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Chip sealing is the application of a bituminous
binder immediately followed by the application of
an aggregate. The aggregate is then rolled to
embed it into the binder.
Binder Application
Aggregate Application
Rolled
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Advantages of Chip Sealing

• Improved Skid Resistance
• Cost Effective Treatments
• Good Durability (Typically 5-7 Years)
• Ease of Construction
• Chip Seal 1 Mile/Day
• Asphalt 1 Mile/Week

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Disadvantages of Chip Sealing

• Flying Chips Broken windshields and vehicle
  damage
• Noise Considerations Chip seals can be noisy
  to travel on
• Weather Considerations Must be constructed
  during warm, dry weather during daytime only
• Pedestrian Not good for roller-blading
  skateboarding

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Materials
Binders must provide good adhesion, or stickiness

• Aggregates must have following characteristics
• Single-sized, if possible
• Clean
• Angular (not rounded)
• Aggregates must be damp for emulsion use

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Construction Process
Surface Preparation

• Crack Sealing or Filling of Cracks
• Patching Deteriorated Areas
• Cleaning or Brooming Any Loose Material
• Removing Pavement Markers and Delineators

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Construction Process
Binder Application

• Uniformly Apply the Binder Over the Surface at a
  Designed Rate
• Pavement Surface Temperature Should be 55ºF and
  Rising
• Humidity Should be 50 or Lower
• Most Important Step in Process

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Construction Process
Aggregate Application

• Should Follow the Binder Application by no more
  than 90 Seconds
• Should be no more than 100 Feet Behind
  Distributor Truck

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Construction Process
Aggregate Application

• Should Follow the Binder Application by no more
  than 90 Seconds
• Should be no more than 100 Feet Behind
  Distributor Truck

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Construction Process
Rolling

• Initial Rolling by Pneumatic Roller or Steel
  Rollers
• Compaction by Traffic Finishes the Process
• Should be Done During Hotter Weather
• Should Follow Aggregate Spreading by no more
  than 500 Feet
• Minimum of Two Rollers Should be Used to Cover
  the Full Width of the Chip Spreader

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Construction Process
Brooming

• After Chip Seal, Excess Aggregate Must be
  Broomed Off
• Within 2 to 4 Hours after Sealing

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Possible Problems

• Bleeding Too much binder leading to leaking
  of emulsion
• Traffic Control Ensure that vehicles do not
  drive on binder application
• Shelling Aggregate not applied in a timely
  manner. Binder sets. Aggregate does not stay
  in place.

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Comal County Canyon Lake Spillway Canyon
June 26, 2007
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Storm Total for 1998
1998 Storm Totals
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Storm Total for 2002
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Structural Flood Control Measures in Comal County
Canyon Reservoir
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Structural Flood Control Measures in Comal County
Emergency Spillway
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Structural Flood Control Measures in Comal County
x
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