Download Hot In-Place Recycling (HIR) of Asphalt Pavements: Processes, Advantages, and Techniques and more Slides Civil Engineering in PDF only on Docsity!
Description
On site, Hot In-Place Method That Rehabilitates Deteriorated Asphalt Pavements and Thereby Minimizes Use of New Materials Depth Recycled: 20-50 mm (25 mm Most Common)
4 Basic Steps
Softening Pavement with Heat
Scarification or Mechanical Removal of Softened Material
Mixing with Recycling Agent, New Aggregate, New Binder, or New Mix
Laydown and Paving
Advantages of HIR
Pavement Geometrics Preserved Corrects Surface Distresses Not Caused by Structural Inadequacy Can Modify Existing Surface Mix
Advantages of HIR
Can Improve Surface Frictional Resistance Relatively Cheap Needs Minimal Traffic Control
HIR Processes
Surface Recycling Repaving Remixing
Surface Recycling
Rehabilitation Process That Restores Cracked, Brittle, and Irregular Pavement in Preparation for a Final Thin Wearing Course Depth of 20-25 mm Most Common ( mm Possible)
Surface Recycling
Single-Pass Method
Two-Pass Method (HMA Overlay Placed as a Separate Operation After Surface recycling)
Schematic of Surface Recycling
Heater
Scarifier
Surface Recycling Equipment
Road Before Recycling Recycling
Advantages
Elimination of Minor Rutting, Shrinkage, Cracking, and Raveling
Very Thin Overlay (12 mm) Can be Used to Yield Economical, Skid- Resistant, and Virgin HMA Surface
Schematic of Multiple-Pass Repaving
Multiple - Pass Repaving
Heater-Scarifier New MixPaver Roller
Single-Pass Recycling
Heater-Scarifier-Paver^ New Mix
Single - Pass Repaving
Heater-Scarifier-Paver New Mix
Remixing Process
Heating Asphalt Pavement 37.5-50 mm Scarification and Collection of RAP in Windrow Add Virgin Aggregate, Recycling Agent, or Virgin HMA Mix Mix in a Pugmill Spread Recycled Mix and Compact
Advantages
Elimination of Rutting, Cracking, and Oxidation in Top 50 mm of Asphalt Pavement Restoration of Existing Asphalt Mix to Desired Mix Composition and Strength by Adding New Aggregate, Binder, or New Mix
Schematic of Remixing Method
Single Pass Remixing Equipment
Heater
Scarifier
Hopper
Single Pass Remixing
New Mix Heater Heater, Miller Paver and Mixer
Two Stage Remixing
After Before
Road Before and After Recycling
