Lezing over inspectie m.b.v. radarsystemen met als cases de Waddenzeedijken te Friesland en Groningen Timo Saarenketo, PhD Managing Director Roadscanners FINLAND
Tomi Herronen, MSc Office Manager Roadscanners FINLAND
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CONSULTING - SOFTWARE - R&D - ROAD SURVEYS – INSTRUMENTS
Focus: existing traffic infrastructure management
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ROADSCANNERS 2009 Rovaniemi
Tampere
Helsinki Borlänge Tallinn
Brora
Projects 2009 Finland, Sweden Denmark, Holland Scotland, Ireland Germany, Austria Hungary, Slovenia Bulgaria, Greece Azerbaidzan, Iran Spain, Portugal South-Africa, Angola USA, Canada, China, Armenia Guatemala, Brasil Thailand, Antarktika
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ROADSCANNERS SPECIAL EXPERTISE: Ground Penetrating Radar (GPR) Technique • Service, Software, Training, Turn Key Systems
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Pavement Diagnostics
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ROADSCANNERS SOFTWARE PRODUCTS • Road Surveys, Railway Surveys, Bridge Surveys, Geotechnical Surveys
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ROADSCANNERS SPECIAL EXPERTISE: • GPR and other NDT technique based integrated road surveys and rehabilitation design systems
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GPR Analysis Options: 1.Time 2. Frequency
Amplitude
Amplitude
Central frequency
Time (ns)
Amplitude plotted against time Theory of GPR/ 5
Band width Frequency (MHz)
Amplitude spectrum plotted against frequency Copyright Roadscanners Oy 2008. All Rights Reserved.
ELECTRICAL PROPERTIES OF MATERIALS ? 1. MAGNETIC SUSCEPTIBILITY 2. ELECTRICAL CONDUCTIVITY 3. DIELECTRIC VALUE
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FACTORS AFFECTING CONDUCTIVITY AND DIELECTRICITY • structure of medium • size of structural elements • electrochemical nature of elements • porosity • volumetric water content • water distribution (amount of free water) • ion concentration • temperature • pressure • density Copyright Roadscanners Oy 2008. All Rights Reserved.
DIELECTRICITY AND ELECTRICAL CONDUCTIVITY AS FUNCTIONS OF OF FREQUENCY Dielectricity
Conductivity or Dielectricity
Interface polarization
According to Keller and Frischknecjt 1966
Molecular polarization
Ionic polarization
Electronic polarization
Conductivity
Frequency Copyright Roadscanners Oy 2008. All Rights Reserved.
FACTORS AFFECTING DIELECTRIC VALUE OF COMPOSITE MATERIALS
• Individual
value of composite materials • Volume fractions of components • Geometrics of components • Electrochemical interaction between components
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1994 – 1995: TEXAS TRANSPORTATION INSTITUTE: MEASURING ELECTRICAL PROPERTIES OF ASPHALT COMPONENTS
12
#14 Tohmo Granite , K´dry #14 Tohmo Granite , K´ads #6 Lime stone K´-dry
10
#6 Lime stone K´-ads
8
#2 Gran/Bas K´-dry
6
#2 Gran/Bas K´-ads
4 2 0 0
1 4 dielectric value, real part K´
real part K´
14
2
16 12 10
3
8
#6 Limestone K´´-ads
6
#2 Gran/Bas K´´-dry
4
#2 Gran/Bas K´´-ads
2
frequency (GHz)
Laguna bitumen
3,6
0 0
0,5
1
1,5
2
frequency (GHz)
3,2
K'-fresh K'-10h aged
2,8
K'-15h aged
2,4 2 0,000
#14 Tohmo Granite, K´´dry #14 Tohmo Granite, K´´ads #6 Limestone K´´-dry
14 imaginary part K´´
16
1,000
2,000
frequency (GHz)
3,000
2,5
3
GPR AND OTHER NDT DATA INTEGRATION GPR + Pavement Surface Properties HMA air voids content Moisture in old AC pavement Pavement distress Pavement roughness (poor man´s IRI)
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GPR SURVEYS ON DIKES 2007 Tests in The Netherlands
GPR SURVEYS ON DIKES 2007 Test Results: Friesland; 1.0 Ghz horn antenna data
seaside
Upper dike
GPR SURVEYS ON DIKES 2008 Tests on a site near St.Jacobiparochie
Surveys conducted: GSSI traditional pulse GPR - 1.0 GHz horn antenna - 2.2 GHz antenna
3d radar 31 channel GPR Digital video
GPR SURVEY SYSTEMS GSSI GPR surveys - two antennas - 36 lines, 105 meters each - 0,5 meter line separation - 20 scans per meter
3d Radar GPR surveys - 31 channels used (2.4 m antenna width) - 7 lines (total of 200 individual profiles) - approx 13 scans per meter
GSSI 1.0 and 2.0 GHz data ac aggregate Soil fill ac aggregate Soil fill
GSSI GPR survey results – depth of bituminous layers Top
Sea
Depth chart based on 1.0 GHz antenna data. Scale 150 to 350 mm.White and black dots represent drill core samples.
Top
GSSI GPR survey results: Evenness of the surface based on antenna bouncing data
Clarification of antenna bouncing The distance from antenna to the surface (travel time of the EM wave)is measured in the survey.
GSSI GPR survey results: Evenness of the surface based on antenna bouncing data Top
Sea
The antenna bouncing map. The scale is Âą 75 mm. The pattern of up-down structure is clearly visible. White and black dots represent drill core samples.
GSSI GPR survey results: Asphalt surface dielectric value 1.0 GHz horn antenna data Top
Sea
Map of dielectric values of the surface (approximately top 30 mm) based on 1.0 GHz horn antenna data, scale 3 to 6 (blue to red). The red vertical line in the beginning and in the end are reflections from the aluminium tape used as a marker. White and black dots represent drill core samples.
GSSI GPR survey results vs. ground truth data
Top
Sea
Map of dielectric values of the surface (approximately top 30 mm) based on 1.0 GHz horn antenna data, scale 3 to 6 (blue to red) compared to visual inspection of the surface (from the report “detectie van aangetast asfalt onder eenoppervlakbehandeling�)
GSSI GPR survey results: Asphalt surface dielectric value 1.0 GHz vs 2.0 Ghz horn antenna data Top
Sea Top
Conclusion: Moisture and main defects are mainly at depths deeper than 25 mm‌
GSSI GPR survey results: Asphalt surface dielectric value= 1.0 GHz - 2.0 Ghz horn antenna data
Conclusion: Moisture (and main defects) can be related to changes of surface shape
GSSI GPR survey results: Asphalt surface dielectric value 1.0 GHz - 1.0 Ghz horn antenna data
1.0 – 2.0 Ghz map
Antenna bouncing map Conclusion: Distress (defect) areas are lifted up from the surface level => Problems are frost related!!!
GSSI GPR survey results: Asphalt surface dielectric value 1.0 GHz - 2.0 Ghz horn antenna data
M5 Pavement Diagnostics -Hungary
Patches
Cracking
Water outlet
Photos captured from M5 Video
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Reasons for the Problems – can Thermodynamics Explain?
WHAT IS SUCTION? 1. TOTAL SUCTION = a) Osmotic suction + b) Matric (matrix) suction c) Gas pressure suction d) Gravitational suction e) Overburden pressure suction 2. CRYOSUCTION Copyright Roadscanners Oy 2008. All Rights Reserved.
CRYOSUCTION • undependent of total suction AGREGATE 1
• force that causes water (if available) to flow to freezing front, and further formation of segregation ice AGREGATE 2
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F REEZEREEZE-THAW CYCLES AND PAVEMENT DAMAG – CASE B871
Dielectric value
TEMPERATURE
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E4 – Vid Hö Höga Kusten: Salt related asphalt damages1998
HW21 Finland: Salt Related Damages 2001
Damage Process of Kemi- Tornio Motorway Failures in Winter 2001 - 2002 During the fall salty water penetrates into the pavement, parts with higher amount of salt adsorb more water due to osmotic suction
Asphalt Bitumen Bound Base Unbound base
Due to uneven distribution of salt pavement does not freeze evenly and parts with smaller salt amount freeze first
Asphalt Bitumen Bound Base Unbound base
Cryosuction is developed, which adsorps water beneath and aside from the unfrozen parts that have more water
Asphalt Bitumen Bound Base Unbound base
Segregation ice is developed causing frost heave and uneveness – and cause damages in the bound layers. ”Bumps” are smaller at wheelpaths due to dynamic loading.
Asphalt Bitumen Bound Base Unbound base
Bound structures get cracks allowing more water to penetrate in the pavement
Asphalt Bitumen Bound Base Unbound base
Whole structure freeze and differentila �bumps� get mor even due to osmotic forces
Asphalt Bitumen Bound Base Unbound base
How this works on Dikes in The Netherlands
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GPR and Pavement Distress
Poor Quality AC: High AC Surface Dielectric Deviation Copyright Roadscanners Oy 2008. All Rights Reserved.
GPR and Pavement Distress
Good Quality AC: Low AC Surface Dielectric Deviation Copyright Roadscanners Oy 2008. All Rights Reserved.
Dielectric valuea deviation oh 1.0 Ghz antenna Top
Map of Er deviation based on 1.0 GHz antenna data. The red lines in the beginning and in the end are affected by the aluminium marker tape. White and black dots represent drill core samples. Compare to visual inspection map below.
Top
GPR surveys on dikes in Netherlands – Delft 5.3.2009
GSSI GPR surveys – moisture at asphalt foundation level Top
Dielectric values of the bottom of the pavement based on 1.0 GHz antenna data. Again the higher Er-values are reached at the lower part of the dike, close to sea. Blank areas are missing data.
GSSI GPR surveys
Shrinkage cracking in the time slice (red colours) over the whole section. In the subwindow on top a GPR profile and on the left subwindow a transverse profile.
GSSI GPR surveys
Top
Zoomed in image of shrinkage cracking visible in the time slice
GSSI GPR surveys
Shrinkage cracking map (above) compared to antenna bouncing mapTop(below).
GSSI GPR surveys Top
Frequency power spectrum over 0-6 ns time scale (0-37 cm with er = 6), the frequency range of 1000 to 2000 MHz. Data from 1.0 GHz antenna, not filtered.White and black dots represent drill core samples.
Eemshaven dike survey 2009
Dielectric values - surface Dielectric value 2 9
Water (Sea)
High dielectric values
Eemshaven dike survey 2009
Dielectric values - surface Dielectric value 2 9
Water (Sea)
High dielectric values
Eemshaven dike survey 2009
Dielectric values - surface Dielectric value 2 9
Water (Sea)
High dielectric values
Eemshaven dike survey 2009
Dielectric values - surface Dielectric value 2 9
Water (Sea)
High dielectric values Eemshaven dike survey 2009
Dielectric values - surface Dielectric value 2 9
Water (Sea)
�Flat� dielectric values (new/different pavement) Eemshaven dike survey 2009
Dielectric value 2 9
�Flat� dielectricities section
Dielectric Value Deviation and Antenna Bouncing Deviation
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Dielectric Value Deviation and Antenna Bouncing Deviation
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Conclusions • Tests have shown that GPR is a useful tool for detecting damages in the asphalt • GPR data indicates that asphalt damages can be related to salt and freeze-thaw damages – similar damages have been found on roads in Scandinavia • Best results in these surveys with 1.0 GHz (better) and 2.2 GHz GSSI horn antennas • Useful maps: dielectric value of the asphalt surface, Erdeviation, antenna bouncing map, Er of the pavement bottom (base course moisture) • This technique is ready for production phase?
Thank you! Copyright Roadscanners Oy 2008. All Rights Reserved.