Introducción Diseño Superpave

Introduction to Superpave Gyratory Compaction and Mixture Requirements






Asphalt Institute
SP-2
Superpave Mix Design
Superpave Gyratory Compaction and Mixture Requirements


Q Section Objectives
Š Describethe Superpave Gyratory Compactor
Š Review the Superpave mixture requirements
Š Summarize the moisture sensitivity test







Final Result

Participant will know the principles of the SGC and what mix criteria are included in the Superpave system
SHRP Asphalt Research Results• Performance Graded Binder System
– Based on climate and loading

• Superpave Gyratory Compactor
– Mix Design and Field QC/QA

• Superpave Mix Design
– Different levels based on traffic loading
– Aggregate criteria
– Height/Density recordation during compaction
– Volumetric analysisGoals of Laboratory
Compaction Method




• Simulate field densification

– traffic

– climate

• Accommodate large aggregates

• Measure compactability

• Conducive to QC
Intent of laboratorycompaction?





• Simulate the in-place density of HMA after it
has endured several years of traffic in the roadway

• What compactor simulates this best?

• SHRP research identified the best practical compactor - Superpave Gyratory compactor

• SGC better than Marshall or Hveem
Superpave Gyratory Compactor• Basis

– Texas Gyratory

– French operational characteristics

• 150 mm (6 in) diameter

– up to 37.5 mm (1 ½ in)
nominal size

• Height recordation
ram pressure
600 kPa



150 mm dia. mold













1.25 degrees

– Allows consideration of densificationcharacteristics
30 gyrations
per minute
height measurement


reaction frame
control and data acquisition panel






loading ram





tilt bar
mold








rotating
base
Superpave Gyratory Compactors
SGC Compaction Parameters







% Gmm



N Nmax• Ndes selected

< 98.0
96.0











< 90.5










Nini
des
according to:

– temperature
– traffic

• Nini avoids tenderness


• Nmax avoids plastic
10 100 1000

Log Gyrations
mix
AASHTO PP-28 Recommendations





|MESAL, || | |
|20 yrs | | | |
| |Nini|Ndes |Nmax |
| | | | |
| | |...