At the California Asphalt Pavement Association (CalAPA) Spring Asphalt Pavement Conference & Equipment Expo held on March 23-24, 2023 in Ontario, Calif., a presentation titled, "Continuous Asphalt Pavement Density Measurement" was delivered by Maurice Arbalaez, Vice President of Instrotek. This presentation will provide an overview of recent innovations developed to measure in-place pavement density, including insight into the implementation of equipment used to provide a complete density profile of the entire pavement in real-time.

1. PaveScanTM RDM 2.0
Dielectric Profiling System
Innovators in instrumentation technology

2. • Minimize additional compaction
• Rutting
• Minimize water permeability
• Stripping
• Prevent excessive oxidation of the asphalt mixture
• Cracking, raveling, loss of fatigue life
• Provide adequate shear strength
• Rutting
Need for Good Compaction

3. • Asphalt cores
• Nuclear gauges
• Non-nuclear gauges
Single Point Measurements
Field Density Measurements

4. Pavement Defects

5. Continuous Full Coverage (CFC) GPR System
Provides on-site dielectric values of newly laid and compacted asphalt
Provides continuous full coverage density profile and asphalt uniformity
Provides compaction information in real-time, on-site using a 2D map
Provides coring locations
Allow input of core information for calibration and calculation of
%compaction, %void content, and density
Dielectric Profiling Systems (DPS/RDM)

6. Q/C Tool
• Roller pattern issues
• Paver issue
• Asphalt issue
• Delivery issues
• Cross check with other technologies
Q/A Tool
• PWL reports
• Google Earth Reports
• General statistics
Forensic Tool
• Map defective areas
• Limit remediation penalties
Dielectric Profiling

7. • ~ 10 cores / 2000T
• PaveScan: ~ 54,000 samples / 2000T
• 60 scans/sec or 10 scans /ft.
(walking)
DPS Sampling Rates

8. Asphalt
Sub-Layer
DPS
Air Voids
Area of low Compaction
Material Dielectric Value
Air 1
Water 81
Asphalt 4-7
How It Works

9. Field Calibration
• Dielectric measurements at core
locations
• Cores are measured according to ASTM
D2726, D6752, AASHTO T-166 or
AASHTO T331
• Dielectric/density calibration curve is
established and transferred to DPS
• Three filed cores recommended

10. • Single sensor is used with data acquisition system
• Superpave gyratory compactor is used to fabricate 3 cores
• Cores are measures and calibration curve is transferred to DPS
• Drastically Reduces need for field cores
• Collect density and compaction data immediately after deployment

11. • 1-pass data collection
• 2-pass data collection
• Swerve data collection
• Segway
• Vehicle mounted DPS/GPR
• Autonomous robot
Data Collection

13. • No contact with pavement
• Laser guided measurements
• Take measurements along
the entire joint
• Alaska DOT joint density
specification
Joint Measurements

14. Shuttle buggy broke.
Paver sits here
Lower density shoulder
1000ft section
12 lines = 2mi.
of GPR data
~50k points
Roller
sits here
Restart
hiccups
Example Scan

15. Exit 6
Exit 8
3” resolution,
1% calibrated
densities
Low density over
bridge deck
Somewhat better
Bridge mat density
Rich,actionable
detail

16. Current DPS Evaluations

17. •AASHTO PP 98-20 Asphalt Surface Dielectric Profiling System using Ground
Penetrating Radar
•Alaska DOT Mat and Joint Specification - AK Spec 412-2.10
•Minnesota DOT, Massachusetts DOT, New York DOT final phase of trials
Specifications

18. • Provide on-site rea-time feedback for
quality assurance of compaction
uniformity
• Core results can be used to convert
dielectric values relative density
• Assessments of the in-place compaction
variation
• DPS results can be cross-checked with
IC, IR, and other data.
Reference: Asphalt Pavement Compaction Assessment Using Ground
Penetrating Radar-Arrays | Congress on Technical Advancement 2017
(ascelibrary.org)
Research Study

19. • Full assessment of asphalt mat with continuous coverage
• Great tool for quality control and roller pattern setup
• Non-destructive testing method
• Equipment and programs are user friendly with proper
training
• Identify the issue in a proactively
• Not perfect use case for all construction projects
• Logistics during construction
• Cost compared to other tools
• Safety for operators
• Accuracy and calibrations (bad data in bad data out)
• Field condition variables (weather, asphalt mix design,
sections)
•
PaveScan RDM 2.0
Pros
Cons

20. Sustainability:
Reduces Climate Change Impacts

21. MATC: Nondestructive Field Technologies During Asphalt Pavement
Construction - National Initiatives - Trailer - Asphalt - Pavement &
Materials - Pavements - Federal Highway Administration (dot.gov)
DPS Publications - Materials & Road Research - MnDOT (state.mn.us)
PaveScan Studies

22. Thank You!
Maurice Arbelaez
marbelaez@instrotek.com
Office: (919) 875-8371
Mobile: (919) 247-4887