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Pages 21-67

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From page 21...
... Abbreviations, Acronyms, Initialisms, and Symbols AC asphalt concrete AI GPR Activity Index CMP common midpoint DMI distance measuring instrument DOT Department of Transportation FCC Federal Communications Commission FHWA Federal Highway Administration GPR ground-penetrating radar GPS global positioning system GSSI Geophysical Survey Systems, Inc. HMA hot mix asphalt IE impact echo NCAT National Center for Asphalt Technology NDT nondestructive testing PSPA portable seismic pavement analyzer SASW spectral analysis of surface waves 2-D two-dimensional 3-D three-dimensional 15
From page 22...
... Appendix A1 GPR Vendor Survey Responses Feedback from Vendor Survey for GPR Question 1 Do you currently supply equipment that can be configured to meet the proposed requirements? 3d-Radar Yes GSSI Yes MALA Yes IDS Yes Question 1a If yes, please describe the components that you would use, and how they would be configured to meet these requirements.
From page 23...
... Feedback from Vendor Survey for GPR MALA MALA has 2.3 GHz antenna, and can run 6 antennas at a time with ProEx system using multichannel expansion. Each expansion module runs 2 antennas.
From page 24...
... Feedback from Vendor Survey for GPR Question 1c Also, if yes, can you exceed the proposed requirements, and to what degree? 3d-Radar Design goal is true highway speed.
From page 25...
... Feedback from Vendor Survey for GPR GSSI Including all mounting hardware, estimated cost is $200K for the horn system and $150K for the ground-coupled system. MALA Pro-EX $125K max; MIRA has never been sold - strictly a research system.
From page 26...
... Feedback from Vendor Survey for GPR Question 6 What are the features of your process that supports data transfer and analysis? 3d-Radar System uses a fast solid state hard drive.
From page 27...
... Feedback from Vendor Survey for GPR IDS RIS Hi-Pave layer tracking, filtering, can represent cores, like RADAN. Can also represent video data and GPS.
From page 28...
... Feedback from Vendor Survey for GPR MALA MIRA Array - true multipath array. ProEx has speed capability.
From page 29...
... APPENDIX A2 SASW/IE Vendor Survey Responses Feedback from Vendor Survey for Mechanical Wave Methods Question 1 Do you currently supply equipment that can be configured to meet the proposed requirements described in the GPR specifications? Olson YES Geomedia NO – The current single-point portable pavement seismic analyzer (PSPA)
From page 30...
... Feedback from Vendor Survey for Mechanical Wave Methods Geomedia The equipment that is currently under development is an array of eight impact sources and fourteen motion sensors split onto two 3-ft beams with the capacity to measure IE every six inches transverse across the six-foot array. The sensors have a capacity of 42 kHz.
From page 31...
... Feedback from Vendor Survey for Mechanical Wave Methods Question 1e If no, what changes in the requirements would need to be made in order for your equipment to comply? Olson Question does not apply.
From page 32...
... Question 4 Based on your experience, who are the probable buyers for this equipment? Olson Past DOT customers for NDT testing were DOT bridge maintenance.
From page 33...
... Question 7 What are the features of your analysis software that supports our pavement evaluation objectives? Olson Automation of the analysis software as primarily advanced through bridge deck studies.
From page 34...
... Question 9 What is the level of expertise needed to operate the equipment and analyze the data? Olson The technician and engineer need Windows-PC and digital data processing skills similar to operating GPR NDT technology.
From page 35...
... Question 11 Similarly, what do you consider to be potential limitations of your system? Olson There is noise at the sensor pavement contact due to rolling wheel movement and the size of the sensor contact area.
From page 36...
... APPENDIX B1 GPR User Guidelines B1
From page 37...
... Use of Ground-Penetrating Radar (GPR) for Identifying Asphalt Pavement Delamination: User Guidelines Prepared by the SHRP R06D Research Team 1 General Theory Ground-penetrating radar (GPR)
From page 38...
... Method 1: Activity Index (time domain) A GPR indicator defined as the GPR activity index (AI)
From page 39...
... wide range of depths and show a variety of amplitude characteristics in the recorded data. An energy-based study of frequency intervals was performed in areas of known delamination in the three-dimensional radar data.
From page 40...
... Figure B1.2. Areas of delamination based on final algorithm and statistical analysis.
From page 41...
... Figure B1.3. Example GPR system output displays.
From page 42...
... 4 Equipment Calibration and Verification 4.1 DMI Calibration All systems will use some sort of DMI to control the data collection rate and to record linear distance. The DMI will either be attached to the wheel of the survey vehicle, or to a separate wheel associated with the antenna array.
From page 43...
... transmission source. Degree of radio transmission sensitivity will vary with the type of antenna system.
From page 44...
... For project-level work, which generally demands greater detail, data can be collected with a moving closure, and therefore one should use the maximum practical data collection rate for that arrangement. Network-level applications, where the required results are usually less detailed, can get by with a reduced data rate, one which would be suitable for driving speed data collection.
From page 45...
... 8 Test Output Data Quality Control Checks It is highly desirable to check the quality of the data prior to demobilizing from the field site. Quality control can be carried out during lunch breaks or other pauses in the normal data collection process.
From page 46...
... The activity index at the test site was determined by using time slices through the C-scan at regular, overlapping intervals. At the two field sites, the scan sections for activity analysis were chosen by picking the layers of interest in the three-dimensional view and exporting the results to be used as bounding regions.
From page 47...
... we are able to define slices based upon knowledge of the layer depths. It is possible to slice through the boundary between layers and map the boundary activity, or to create slices which are the thickness of the material between adjacent boundaries to examine the activity in each layer.
From page 48...
... Figure B1.5. Three-dimensional radar representation of NCAT site showing "stripped" asphalt layers at 3 ns (1 to 2 in.
From page 49...
... Figures B1.6 and B1.7 show the picked surface reflection and bottom of asphalt reflection. The upper part of Figure B1.6 shows the longitudinal and transverse profile and the waveform defined earlier in Figure B1.3.
From page 50...
... Figure B1.7. Three-dimensional radar analysis sections.
From page 51...
... Note that to create the 3-D cubes of radar data at the test track, the 3d-Radar system used five parallel passes with a 5.5-foot-wide, 21-channel swept-frequency antenna array (140 to 3,000 MHz) , and the individual antenna system used 25 parallel passes with a single 3 GHz antenna.
From page 52...
... Figure B1.10. Florida radar data at the location of Cores 1, 2, and 3.
From page 53...
... Figure B1.11. Florida site activity index plot of region between picked layers.
From page 54...
... Figure B1.12. GPR radar data from the Kansas site.
From page 55...
... Figure B1.13. Line plot showing delamination indicators versus milepost (blue fill = delamination)
From page 56...
... Table B1.2. Example Tabular Output at the Network Level MP Likelihood of Delamination (%)
From page 57...
... APPENDIX B2 GPR Vendors' Features 3d-Radar .................................................................................................................................B23 Geophysical Survey Systems, Inc.
From page 58...
... 3d-Radar High Speed, Full Coverage Ground-Penetrating Radar Solutions (prepared by 3d-Radar, February 2013) 3d-Radar provides ground penetrating radar hardware and software for data collection across an entire swath width at high speeds with high resolution at all resolvable depths.
From page 59...
... The GeoScope Mk IV connects to any laptop via a standard GBit Ethernet connection and the primary interface is via a web browser. No software needs to be installed on the host computer to communicate with the system.
From page 60...
... Equipment – Mounting and Climate Restrictions 3d-Radar step frequency antennas require no warm-up or settling time in cold weather. Operational in both subfreezing and hot climates, the antennas are sealed from the elements and can be exposed to snow and rain without damaging the electronics.
From page 61...
... 3dr-Examiner converts data collected from the frequency to time domain, applies filtering and tuning and can migrate in a self-contained, menu-driven environment. As the data are processed, they can be viewed in three dimensions, with the ability to compare processing settings to determine how to optimize the collected data.
From page 62...
... 7. Equipment Upgrades and Service As improvements to 3d-Radar hardware and firmware are implemented, firmware upgrades to both the GeoScope Mk IV and DX Series antennas can be downloaded from 3d-Radar over the Internet.
From page 63...
... Geophysical Survey Systems, Inc. GPR System Specification (prepared by GSSI, February 2013)
From page 64...
... Lateral spacing of antenna elements Specification: <1.5 feet Response: The minimum lateral spacing for the Model 42000S antenna is 0.75 feet. Lateral coverage per pass Specification: 12 feet (full lane width)
From page 65...
... Response: The RoadScan 30 system supports a vehicle-mounted DMI and/or a GPS for spatial referencing. Detection depth range Specification: 2–12 inches Response: The RoadScan 30 system, configured with the 42000S 2 GHz air-launched antenna, has a detection depth range from less than 1 inch up to 20 inches, depending on the dielectric properties of the medium under test.
From page 66...
... The SIR-30 system software is compatible with all GSSI antennas and provides automatic recognition and setup of GSSI Smart antennas. RADAN 7 is a data processing and analysis package designed for use with GSSI 32-bit data acquisition systems.
From page 67...
... Calibration, Field Validation The only calibration required by RoadScan 30 is the metal plate calibration used to determine the radar propagation velocity of the medium under test. This calibration is performed daily prior to data collection.

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