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HMA PLACEMENT . To Be Covered. Hauling Placement Compaction. Tandem Axle End Dump Truck. High Dump Semi-truck. Belly Dump. Multi-WHEELED Conveyor Feed. Self Propelled Paver. Self Propelled Paving Machine. THE BASIC PRINCIPLE HAS NOT CHANGED MUCH. Self Propelled Paving Machine.
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To Be Covered • Hauling • Placement • Compaction NCAT
High Dump Semi-truck NCAT
Belly Dump NCAT
Self Propelled Paver NCAT
Self Propelled Paving Machine THE BASIC PRINCIPLE HAS NOT CHANGED MUCH NCAT
Self Propelled Paving Machine HMA Flow NCAT
Screed Unit NCAT
Forces On Screed NCAT
ONE OF THE ESSENTIALS FOR A CONSISTENT AND HIGH QUALITY HOT MIX ASPHALT PAVEMENT IS TO PROVIDE FOR A CONTINUOUS OPERATION NCAT
COMPACTION GOOD COMPACTION LEADS TO GOOD PERFORMANCE NCAT
Reason For Compaction • To prevent further compaction • To provide shear strength or resistance to rutting • To ensure the mixture is waterproof • To prevent excessive oxidation of the asphalt binder NCAT
Durability vs Air Voids Stability Cohesion Zone of Highest Durability Flushing Raveling 0 % Air Voids NCAT
Factors Affecting Compaction • Mix Properties • Aggregate • Asphalt • Mix Temperature • Layer Thickness • Environmental Factors • Rollers NCAT
Rollers • Vibratory • Pneumatic-tired • Steel wheeled tandem rollers NCAT
Vibratory Roller NCAT
Pnuematic Roller NCAT
Steel Wheeled Roller NCAT
Extracting A Core NCAT
Questions - ? NCAT