group 6 saman ali akbar sukina hussain - kth.se · traditional two way mesuare density • extract...

Group 6

Saman Ali Akbar Sukina Hussain

Ø  Density???

Ø  The insufficient density    Long-lasting    Reduce the maintenance    Reduece the rehabilitation cost

Ø Low density    Oxidation    Reveling    Cracking    Moisture damage

Ø  Traditional two way mesuare density •  Extract core •  Unclear density gauge

Ø  Researches v  Non-unclear density gauge

§  Non-radioactive tool §  Used electromagnetic (EM) §  Inherent advantages over the nuclear density guage

§  No stringent license §  Specialized storage §  Extra security precautions

Ø  IC }  To provide continouos measurement }  Large coverage }  Commuri developed a neural network }  The IC based on pavment stiffnes }  Loading rate and stiffnes of base layer }  Error measerument cause by deacrese of temperature

GPR Ø  Non destructive tool Ø  A functioning pavement quality control Ø  Compared three candidate density prediction

Ø  Rayleigh mixing

GPR Ø  Several advantages

§  Collect data quicker than coring §  Air-coupled GPR system

Ø  GPR installation

Ø  Anteena send EM waves Ø  Ground-coupled antenna Ø  Air-coupled antenna Ø  Antenna frequency

Ø  Material property for GPR Ø  Permittivity Ø  dielectric

}  General Concept §  An effective tool for QA&QC §  The main challenging the

surface water effect on GPR reflect signal

}  Advanced Transportation And Research Engineering Laboratory(ATREL)(University of Illinois)

§  2 GHz air-coupled antenna §  Limestone aggregate & PG

64-22 §  Test temperature 63-66C §  3ft*3ft square are tested §  250 mL water §  1.7m wide drum (compactor) §  Compressed air sprayer

Whole Frequency spectrum Magnification of part of the spectrum for better visualization

Figure a. Figure b.

Filtering GPR surface reflection signal

Ø  Comparison of feature value plots using different feature extraction approaches

Ø  Summary of test project

}  GPR data collection procedure

Normalized feature value versus passing number of compactor

Ø  Thickness and density measurement after construction