Royal Institute of Technology Stockholm, April 15th 2014

AF2903 Road Construction and Maintenance

Placement of Hot Mix Asphalt

Dr. Alvaro Guarin

Highway and Railway EngineeringDepartment of Transportation Science

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Asphalt Production (Batch Plant)

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Asphalt Production (Continuous Plant)

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Asphalt Production

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Asphalt Production

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Asphalt Production

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No

Yes

Control segregation

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Tarping Loads

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Bottom Dump truck

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Live Bottom Truck

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End Dump Truck

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Materials Transfer Vehicle

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Materials Transfer Vehicle

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Self Propelled Paving Machine

THE BASIC PRINCIPLE HAS NOT CHANGED

MUCH

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Types of Pavers

Wheel type

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Types of Pavers

Track type

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Pavers (Key parts)

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Material Flow

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Paver Operation

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Operational Principles of the Screed

• Self-leveling concepts

• Screed response versus distance

• Forces acting on a screed

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Main Forces Acting on Screed • Speed of paver

• Head of material

• Angle of attack

• Other forces Pre-compaction Screed weight

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Head of Material (Screed)

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Types of Grade Reference

• Stringline

• Mobile reference

• Joint matching shoe

• Sonic sensor

• Laser guided controls

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Stringline

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Mobile Reference

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Joint Matching Shoe

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Sonic Sensor

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Laser guided controls

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Mixture Laydown Problems

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Centerline Segregation

Mixture Laydown Problems

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Questions?