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Density Profiling System Protocol | May 08, 2020Chapter 3: DPS Pre- and Post-Paving Procedures

Chapter 3: DPS Pre- and Post-Paving ProceduresDensity Profiling System Protocol


3.0 IntroductionThis chapter provides protocols to ensure that the relevant paving information is input and stored, and equipment is setup, calibrated, and stored in a way that allows for collection and export of quality data that can be referenced to relevant paving operations. The three types of field data collection (Dielectric Quality Assurance, Routine Collection, and Core Validation) are presented in detail in Chapters 4, 5, and 6, respectively.

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3.1 Pre- and Post-Paving ProceduresThis chapter provides guidance and best practices for pre- and post-paving activities using the GSSI PaveScan Rolling Density Meter (RDM) to continuously monitor and inspect the field compaction efforts of bituminous pavements. This protocol provides supplementary protocols and tips. It is assumed that the user is familiar with the PaveScan RDM Manual.

3.1.1 Parts ChecklistMake sure you have the correct parts for this setup by collecting the items shown in Figure 3.1 from your equipment case (pay attention to what goes where, this will make it easier and faster when you take it apart). The DPS is composed of three 2-GHz Ground Penetrating Radar (GPR) antenna(s) and an RDM concentrator box for continuous collection of pavement surface dielectric. This package includes batteries, charger, data and sensor cables, a calibration plate, and touchpad. The user can also pack items such as a level, measuring tape, and zip ties which can supplement field data collection. The optional GPS equipment is also pictured, which is composed of a receiver and a controller. This package should also include chargers and data and power cables to connect to the tablet. The system should also come with a mi-fi or other system that provides necessary internet connection to your agencies virtual reference station (MnCORS virtual reference station is used by MnDOT). The devices should be setup to export a standard NMEA string for the Pavescan software to be able to read in the GPS coordinates. Figure 3.2 shows the wheel-cart with a Distance Measuring Instrument (DMI) embedded in the cart-wheel. The cart comes with mounting fixtures for carrying and hauling the RDM devices while collecting surface dielectric data at walking speed.

If testing for the entire duration of paving some of the following extra parts are recommended:

Extra Pavescan battery packs (long lithium ion batteries)

External battery power source for tablet

Extra GPS battery packs (if using external GPS receiver)

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Figure 1: Equipment checklist for DPS operation. (1)

Figure 2: RDM Cart required for DPS operation.(2)

3.1.2 Cart AssemblyFollow the manufacturer’s assembly instructions and supplement them with the assembly tips given here.

Set the orange PaveScan Unit in the metal holder with the lock facing the 4 | P a g e


handles.

Unscrew both knobs on the front of the cart (Figure 3.3a). Place the Scaled Metal Bar, with the holes facing away from the cart, on the front part of the cart where you just removed the knobs (Figure 3.3b). Line up the holes and screw the knobs back on (Figure 3.3c).

Metal bar installation. (3, a, b, c)

Loosen the two knurled clamping knobs on the antenna mounting bracket, but do not remove. The antennas can be placed in any order, but it is recommended to place the sensors in order from smallest to largest (i.e. 21, 22, 24) as shown in Figure 3.4 from left to right from the cart operator’s perspective. Make sure to push the sensors in all the way. Center antennas on the bar at offsets selected for data collection and tighten the clamping knobs.

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Figure 3: Antenna Placement. (4)

Continue with manufacturer assembly instructions in the user manual until your cart looks like Figure 3.5.

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Figure 4: Assembled Cart. (5)

3.1.3 External GPS Setup (Optional)The pavescan software allows for use of an external GPS as long as the string is submitted in NMEA format. The setup here is given using a Trimble R8 receiver with the settings conFigured using a Trimble TSC3 to allow for NMEA strings to be submitted from Port 2.

Flip the GPS Unit upside down and pinch the two yellow buttons to remove the battery cover (Figure 3.6a). Place the small battery pack in the removable cover. Notice the + and – on both (Figure 3.6b). When inserting the battery these should be on the same side (Figure 3.6c). Replace battery cover.

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(a)

(b)

(c)

Figure 3.6. GPS Setup.

Screw the GPS Unit onto your mounting mechanism (the MnDOT system uses a threaded rod).

Using the serial port cable and serial to USB cable (Figure 3.7a), connect the USB end to the TOUGHPAD, and the other to the underside of the GPS Receiver (Figure 3.7b). Tighten the screws to ensure it will not get yanked out.

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Figure 3.7. Connecting GPS to mount and tablet.

3.1.4 Required Pre-paving InformationCorrect input of project and testing characteristics is critical to successful use of the DPS. Table 3.1 gives a list of information related to DPS testing that should be known prior to testing each day and documented each time the equipment is used on a paving project. While most of the information is generic to the various paving projects of the diverse agencies in the pooled fund, these inputs are mainly designed to give a template that works for MnDOT, and each State has flexibility to use similar terminology that fits their State’s nomenclature. The table gives an example and description of each input in the second column. Future versions of the software will allow this information to be pre-loaded into the software using input files to simplify the process and allow for creation of input files in an office environment rather than while setting up the equipment on-site. This is designed to allow for engineer oversight and to reduce the possibility of errors in input values. Some of this information will need to be documented outside of the current Pavescan software.

Table 3.1. Input information associated with DPS field testing.

National Category (MnDOT Terminology)

Example Description

Project ID (SP#, SAP#, etc.)

SP7906-96 All information tied to the construction project is tied to this number

Route Designation (TH#, CSAH#, etc.)

TH 61 Route System (trunk highway, county road, etc.) and number used by general public to identify route

Material HMA Material (HMA, WMA, SMA, etc.) applied to the surface being measured

Project Location (County) Wabasha Typically county to allow correct projection of GPS to county coordinates

Date Paved 9/16/2019 Date of paving (ideally this should be the same date of testing)

Lift # L1 Top layer at the time of DPS testing. For example in a two lift system the first layer placed is Lift 1 (L1) and the final lift is lift 2 (L2).

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Example Description

Divided Highway No “No” means the lanes share the same centerline, “yes” means they don’t.

Lane Extents (AAB-CCD) CL-12R The location of the left and right edge of the production area with respect to the centerline, facing in the direction of increasing stationing. Stationing typically increases from West to East and South to North. Each character of the abbreviation is defined as the following:

AAB – CCD

AA - The offset distance (in feet rounded to the whole number) from the centerline to the near edge of the production area (e.g., CL, 12, 24). CL reflects the Center Line.

BB - R or L, to reflect Right (R) or Left (L) of Centerline, in the direction of increasing station numbering.

CC - The offset distance (in feet rounded to the whole number) from the centerline to the far edge of the production area (e.g., CL, 12, 24). CL reflects the Center Line.

DD - R or L, to reflect Right (R) or Left (L) of Centerline, in the direction of increasing station numbering.

Direction of Travel (NB, SB, EB, WB)

SB Direction of travel on the paved lane extents

Field ID (Test Summary Sheet #)

TSS #60-428 Identification that is tied to all mix quality control and quality assurance measures. Typically this counts up every 1000 tons for MnDOT

Sensor Lateral Offsets Serial#72=0.5;

Serial#74=2.5;

Serial#75=4.5

GPS antenna ID and location relative to the centerline (CL).

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Example Description

Stationing Start 18550 Stationing without the “+” sign. The example value would be displayed as 185+50 on a survey stake but input and exported without the “+” for ease of processing.

Right Edge Type UCS This can be any of the following categories:

UCS – Unconfined shoulder joint

CS – Confined shoulder joint

UCCL – Unconfined centerline joint

CCL – Confined centerline joint

HJ – (Joint) Heater joint

EJ – Echelon paving joint

NJ – Widened lane paving so that there is no joint at the edge in question.

Left Edge Type CCL This can be any of the following categories:








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Example Description

MnDOT Model Dielectric to AV% Input Coefficients

a= 0.2

b=10.6

c=5.87

g=4.07

delta=0.008

Set coefficients of the model based on puck testing results. Ideally the puck program should automatically create a file that Pavescan reads in directly.

3.1.5 Equipment StartupThis section provides instructions for starting up the RDM system. It is important that the user performs these operations in the order they are presented herein.

Start the RDM Concentrator: Turn on the RDM concentrator by pressing the start button on the front panel of the box. A ring around the start button will light-up indicating the powering on of the RDM and the sensors

Power-up ToughPad computer: Turn on the computer by pressing and holding down the power button for a few seconds. The computer will take 20-30 seconds to start. The Main Menu (shown in Error: Reference source not found) of the PaveScan RDM application will automatically appear on the screen of the computer. The PaveScan RDM software can also be started via a desktop shortcut icon that appears on the computer’s desktop.

RDM System ready: A status indicator, displayed on the top-right hand corner of the screen, will inform the user when the RDM system is ready for use. The word Running will be displayed next to the indicator and the Collect tab, on the main body of the menu, will turn to green. The user can also access the Playback and System Setting tabs to change the settings or view previous projects.

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Figure 5: PaveScan RDM software: Main Menu (8)

Starting GPS (if using optional external GPS)

o Turn on the GPS Receiver, Mifi wireless internet service, and the Controller.

o Ensure that the Controller is connected to the GPS Receiver and has an internet connection from the MiFi

o On the GPS Controller, select the following (or your State’s equivalent of connecting to the Minnesota Virtual Reference Station (MnCORS):

General Survey

Jobs

New/Open Job

Create a new job with the correct county, via the menu, or open an existing job

Measure

MNCORS2

Measure Points

MNCORS2

Wait for initialization to be gained. You will verify that the connection was 13 | P a g e


made in a later step.

3.1.6 Software Settings DescriptionThis section provides instructions for input of the proper software settings. Please note that most of these settings are stored to default as the most recently selected value and just need to be double-checked periodically, rather than input every time. The System Setting button in the Main Menu page will open a new page containing several user-adjustable settings (shown in Figure 3.9). Instructions for adjusting these settings are provided in this section.

Figure 6: PaveScan RDM software: System Settings page (9)

RDM Collection Method: Set the survey method appropriate for the planned RDM testing by pressing the Collect Option tab. In the current version of the PaveScan RDM Software, three survey methods are proposed: Walk, Fast Walk, and Vehicle. The measurement densities (number of sampling per unit distance) corresponding to these survey methods are 10, 5 and 1.64 scans/ft, respectively. During data collection, an over-speed indicator is displayed on the screen to help maintain an adequate sampling speed. Select Walk.

Survey Wheel Calibration: An accurate distance calibration is crucial for collecting accurate RDM data. Perform distance calibration on a straight, flat, clean and at least 100-ft long segment (the longer the calibration distance, the more accurate the calibration). Step-by-step instructions for the survey wheel calibration are given next, although this does not need to be completed every time you conduct a survey.

o Press the Survey Wheel Cal tab in the System Setting. Open the 14 | P a g e


calibration page shown in Error: Reference source not found.

o Enter the calibration distance

o Line-up the cart or vehicle used for the RDM data collection at the starting position

o Press the Start button to initiate the calibration

o Move the cart or drive the vehicle past the starting position along the calibration track until you reach the ending point.

o Press Stop and then Save to accept the new calibration number or Cancel to keep the old one. When saving a new calibration number, the system will automatically restart.

Figure 7: RDM software: Survey Wheel Calibration page (10)

Project Defaults: The Project defaults are all the settings that can be preset and are inherited in newly created projects. These settings include units, GPS Settings, and preferences. Pressing the Project Defaults button opens the Project Properties window shown in 3.11.

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Figure 8: RDM software: Project Properties page (11)

Distance Units: Set the desired distance unit. The proposed options are feet and meter units.

Calibration Type: The measured dielectric values can be converted to physical properties typically used to assess the quality of compaction of bituminous pavements, such as (1) Percent voids, (2) Density, and (3) Percent compaction. These conversions are accomplished through least-square fit models that are calibrated using measured dielectric and density or void content measured at the same spot as the dielectric. Select the calibration method planned for the project.

Density Unit: Set the unit used for the physical property (calibration type).

Core Calibration Equation: The core calibration equation defines the model by which the measured dielectric values are related to the spot density or void measurements. The user can select between two proposed models: 1) Exponential Least Square Fitting and 2) Linear Least Square Fitting (additional features will be added in the next version of the software)

Project Management Method: This tab offers two methods for managing the files during RDM data collection: Filenames and Lane Location. If Filenames is selected, the user will be prompted to input a file name during the testing and data collection. When Lane Locations is selected instead, all the collections performed in one project will be treated as part of the unique lane and will differentiate only by the stationing ranges. All the collections can be viewed individually or as part of the segments that constitute a project. Select Filenames.

Use Stationing Format: This option, when checked, permits the user to use

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stationing format (i.e., 52+70) instead of decimals (i.e., 5270-ft).

Auto Start Distance: When this option is selected, the End Stationing in the last saved file will be automatically used as the Stating Stationing of the following file. The starting distance value is always editable before starting data collection. Select Auto Start Distance.

Cancel: Canceling will return the user to the previous screen without saving any changes made in the Project Properties window or other windows accessed through it.

GPS settings (optional): The GPS settings are adjusted from the Project Defaults page (see Figure 3.11). Pressing the GPS tab opens the GPS settings’ page shown in 3.12. The current GPS receiving port is displayed on the top-right hand corner of the page. The user can make use of the COM Port dropdown list (list of all available Ports) provided in the page to locate and set the actual COM port used by the GPS receiver. If the correct Port is selected, pressing the Test Setting button will populate the GPS coordinates in appropriate cells. Leave the default settings for the remaining parameters.

Figure 9: RDM software: GPS Settings’ page. (12)

Lane Names: This option allows the user to specify the names of the lanes used in the project. For example, the user can choose to indicate that Lane 1 refers to Inner lanes of the project and so on.

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Export Options: The export options can also be customized from the Project Defaults page. The user can select the following options by checking them:

o Use Extended Header: to include all the available project information on each exported file

o Provide Segment Statics: to produce statistics for each tested station interval in a separate output file

o Output Segment Interval: to define the segment interval over which the statistics are to be calculated

3.1.7 Input of Project SettingsThis section consists of basic instructions for input of the necessary project information for successful collection of DPS field data. It is assumed the DPS is already setup and powered on as described in sections 3.1.2 and 3.1.5. It is also assumed that the user has an understanding of the settings described in section 3.1.6. At this point the following tasks can be completed.

The Collect button in the Main Menu page will open the Project Settings page shown in Figure 3.13. The user can create a new project, recall an existing project and adjust the Project Settings from this page. Each user input is labelled A through G in Figure 3.13 for the purposes of this protocol. The settings are filled out according to the example data given in table 3.1. Table 3.2 gives a brief explanation and format of each of these settings.

Figure 10: Project Level Settings.(13)

Table 3.2 Project-level input settings format and decription.

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Setting Short Description and Example

Long Description

A: Project Group

Project ID

Example:

SP7909-96

Specify the Project Group. This is the identifier your agency uses to house all project information

B: Existing Project Name

Route_Lift#_Date

Example:

TH61_L1_2019-09-16

The name associated with the project. Project names must be unique. A new project is created by clicking the New Project button. When this is selected, a window appears asking if the user wants to transfer the settings in the current project to the new one. Select yes if you want to use the same settings as the current project or cancel to recall the default project settings. This indicates the road tested, lift number, and date of paving (agencies can go without data of paving if they want to keep multiple days in the same project. If any of these three categories change a new project name should be created. Note that the route may also include N/S/E/W if there is a unique alignment for the different route directions as can be the case in a divided highway. This will be the folder name where the exported data is stored.

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Long Description

C: Location County

Example:

Wabasha

Optional entry for specifying information related to where the data are being obtained. This information is exported with the data. If you are using an external GPS, this should be set to the county where paving occurs since this is convenient to be able to use projections for conversion to county coordinates.

D: Lateral Offset

Reference

Reference Line

Example:

Distance from Lane Edge

Optional entry for specifying the reference used for the lateral coordinates assigned to a file. Examples include: curb, outside lane stripe, or pavement edge. This will be included in the exported data. See the manufacturer’s manual for more details on specifying the Lateral Offset Reference. Select the option that most closely resembles your reference line. See Chapter 5 for clarification on how to deal with offset reference.

E: Lateral Offset

Reference Side (looking Up-Station)

Side of Reference Line

Example:

Left

When operating the PaveScan RDM, this was originally designed to be the side of the cart that the Lateral offset reference is located (i.e., where the curb is) when the cart is facing the direction where distance values increase (i.e., the increasing station direction). This method will not be employed moving forward and is discussed further in Chapter 5. For consistency, always select Left. This option will no longer be used in the next version of the software.

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Long Description

F: Equipment Operator

Initials

Example:

KEH

Operator documentation that can help troubleshoot or identify if certain operators bias results

G: Comments User Comments

Example:

Superpave 5 Mix

Place to document anything unique about the project.

Additional buttons in this menu include Core Calibration used to convert dielectric to AV% when core or puck dielectric and AV% results are input (this will be updated in the next version of the software) and Properties (which was described earlier).

After setting up the Project group the first day, it will be saved and should be used for the remainder of the testing associated with that project ID. This is done by selecting “New Project” followed by “New Group”

For the remainder of the days of testing make sure the correct project group is selected then select “New Project” and enter the project information starting with B: Project Name and working your way down the list as shown in Figure 3.13 and Table 3.2.

Settings to double check

o Make sure the “Auto Start Distance” box is checked (see Figure 3.14)

o Checking GPS settings (optional):

Select properties.

Select GPS Settings (see Figure 3.12).

Check that the “GPS UTC” is counting up. If the GPS setup is not correct, try adjusting the COM Port number and Test Setting. Once the settings are right go back to the Properties page and select SAVE.

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Figure 11: Make sure Auto Start Distance is checked. (14)

3.1.8 Sensor CalibrationThe manufacturer recommendations for calibration of the technology should be followed, but this subsection provides some guidance for how it is completed using the RDM 1.0. Clicking the Save button in the Project Setting pages takes users to the Sensor Configuration Window shown in Error: Reference source not found. Once the DPS software locates the sensors connected to the DPS box, the page is updated to display the sensors as in Figure 3.16.

Figure 12: RDM software: Sensor Configuration page (searching sensors) (15)

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Figure 13: RDM software: Sensor Configuration page (with sensors) (16)

The user must ensure the sensor identification numbers and relative location of the sensors are indicated in appropriate fields:

Use the dropdown list to associate the sensor identification number with the sensor that most closely matches its position on the cart. The sensor identification number is the serial number found on the side of the sensor. In the example shown above, Sensor # 8 is located on the left side of the cart from the perspective of the person pushing the cart when looking at the sensors (not from looking at the sensors from the front). Therefore, the leftmost sensor should be positioned on the left side of the window, as shown in the image.

Set the crossline positions of the left and right sensors. The cross-line position reference is the distance of the sensor from the center sensor. Distances are positive numbers such that the value input on the left is distance to the left of the center sensor, and similarly to the right for the rightmost sensor. It is a good strategy to always place the same sensor in the same relative location: left, center, or right, with lowest number on the left and highest on the right for consistency. The PaveScan system assumes that the center antenna is at the exact center of the cart.

Save the sensor configuration by clicking the Save Button. Note that the saved system configuration will be remembered with the project so that the next time the system is started the relative positions will be recalled.

File Information: Clicking Save in the Sensor Configuration page takes the user to the File Information page shown in Error: Reference source not

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found. Press Collect Data without adjusting the settings, since we need to calibrate the sensors before collecting data. A more detailed discussion of the File Information page is given in Section 3.1.10).

Figure 14: RDM software: File Information page (17)

a. The program will inform you that you need to calibrate before you can start, select OK (Figure 3.18).

Figure 15: Notification that calibration must be performed. (18)

Sensor Calibration must be performed every time the system is started up. The sensor calibration should be performed on a plane surface.

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Sensor Calibration: The Sensor Calibration page shown in Error: Reference source not found 3.19 is accessed by clicking the Collect Data button in the File Information page. Step-by-step instructions for sensor calibration are provided in the manufacturer’s manual. The important features of the calibration are outlined in this section.

Figure 16: Sensor calibration page when ready to conduct air calibration. (19)

Warming up is automatically triggered and completed before the calibration of the sensor. This session lasts 10 to 15 minutes. When the warming up session is completed, the Air calibration button turns to green (inviting the user to start the air calibration session)

Air Calibration: This process requires that all the sensors be lifted at least 2-ft off the ground or facing upwards (basically any arrangement that keeps any obstruction in the direction the signal is sent at least 2 ft. away). Pressing the Air button will begin the airwave measurement session. This session lasts 15-30 seconds, when completed, one of the sensor calibration buttons turns to green (inviting users to start the metal calibration session on the highlighted sensor).

Metal Calibration: All the sensors are faced downwards and fixed at the height specified for the data collection in the orientation it will be relative to the pavement during testing. The metal calibration is carried out one sensor at a time following the instruction displayed on the screen. The sensor to be calibrated next will be highlighted in green as shown in Error: Reference source not found. Using the level, make sure that the sensor and the metal plate are parallel. For example, if the metal plate is slightly tilted, the sensor should be tilted to match. That is why it is best to calibrate the sensors on relatively even ground.

This process is repeated until all sensors are calibrated and the Collect Data button turns green. The user should position the metal plate below the

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center of the highlighted sensor to within ± 1-inch (see example in 1) and press the highlighted button, which will turn orange during calibration. The metal plate calibration lasts 5 to 10 seconds. Once it is completed, a different button will turn green.

Press Collect Data, then Cancel to return to the File Information page. Background on Stationing and Offset is given in the next section in preparation for the file information page.

Figure 17: RDM software: Sensor Calibration page (metal calibration) (20)

Figure 18: Positioning of metal plate for sensor calibration (21)

3.1.9 Reference Line and Station/Offset ConventionsIn order to assist in inputting the correct values in the file information section some discussion on reference line and stationing and offset are given in this

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section. For the purposes or DPS testing, all terminology (left, right, positive, negative etc.) for describing the location of the DPS readings should ALWAYS be given from the perspective of the following:

Location is always presented with regard to where IT is relative to the reference line, NOT where the reference line is relative to IT. This is critically important to remember when indicating offset information.

Location within the cart is always given from the perspective of the user when operating the device, NOT when looking at it from the front.

Location within the project is always described from the perspective of looking in the increasing stationing direction: It doesn’t matter what the direction of travel or paving direction is, the positional information is ALWAYS from the perspective of looking in the up station direction (direction of increasing stationing).

The chosen reference line is unchanging within a given project group, regardless of what lane you are testing on within that project. This is often the centerline – indicated as CL in the alignment file that construction uses to pave the road. If a reference line is switched (for example when switching lanes in a divided highway), you should create a new project name with a unique route indicated.

The ultimate goal for the RDM lane extents information is given in Table 3.1. This gives the location of the left and right edge of the production area of each lane with respect to the centerline, facing in the direction of increasing stationing. Stationing typically increases from West to East and South to North. In this case, lane extents are expressed in the following format: AAB-CCD [EQ 1] where,

AA is the offset distance (in feet rounded to the whole number) from the centerline to the left edge of the production area (e.g., CL, 12, 24). CL reflects the Center Line.

B is R or L, to reflect Right (R) or Left (L) of Centerline, in the direction of increasing station numbering. This is blank if the edge is the CL.

CC is The offset distance (in feet rounded to the whole number) from the centerline to the right edge of the production area (e.g., CL, 12, 24). CL reflects the Center Line.

D is R or L, to reflect Right (R) or Left (L) of Centerline, in the direction of

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increasing station numbering. This is blank if the edge is the CL.

In this convention, the lane extents are indicated by feet left or right of the reference line (often indicated by centerline (CL)). For example, the CL-12R designation would indicate a 12 ft. lane right of centerline (all right and left designations are from the perspective of looking up station). Ultimately, the ability to designate the type of edge (unconfined joint, confined joint, etc.) is good information to be able to store with each dataset, since this information affects the compaction effort, especially near the pavement edge of an unconfined joint.

The following terminology is proposed to describe production area offset extent types (note: any joint separating traffic lanes is considered a centerline joint in this terminology. In this case you can have more than one centerline joint even though only one could possibly also be the reference line):








In the future, the current Lateral Offset Reference (LOR) terminology of the current software will be referred to as the Reference Line, which is typically chosen to be the centerline (CL).

Since these conventions can be difficult to keep straight and have major implications to making sure the DPS inputs can be understood by construction personnel some of the points are reiterated below:

The user should ALWAYS give location relative to reference line NEVER location of reference line relative to where they are.

The user should ALWAYS give their location from the perspective of looking up station, and this should NEVER depend on anything to do with the direction of paving, the direction of their RDM cart, direction of traffic, etc.

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Each point on the construction site is either right or left of the reference line with no dependencies.

o This is the convention construction personnel (who will be operating the equipment) are used to and makes it clear that there is only one way to indicate any given point on the job site and it has nothing to do with the direction the user is traveling with their cart.

o In this case, the user will rarely have to change right or left of reference line in the software, whereas if we make Left or Right of reference line something that needs to be input based on direction the user is traveling, they will have to switch the left or right quite often.

In the current version of the software left is indicated by a negative number and right is indicated by a positive number. Future versions of the software will allow for all of the conventions given above including Left and Right of reference line designations.

For added clarification Figure 3.22 gives a schematic of a given example where the DPS cart is collecting data in the decreasing stationing direction. While, from the user’s perspective, they are to the left of the reference line it would be INCORRECT to give a left or negative indication of offset. The offset location of the cart needs to be given from the perspective of looking increasing stationing (not necessarily from the perspective of the direction of data collection). The CORRECT designation of offset from the reference line in this case would be 6 ft to the right (or positive) offset.

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Figure 19: Example schematic showing the cart collecting data in the decreasing stationing direction at an offset of 6 ft right of the reference line (a positive 6 should be input as the offset in this case). (22)

3.1.10 File InformationIn the file information page, the user can enter information explicitly related to each data collection file. Press Collect Data without adjusting the settings (this will take you to the sensor calibration page). While future chapters will give descriptions of inputs specific to the task of the current run (quality assurance of dielectric, mat or joint routine collection, or core validation), the list below gives the generic descriptions of each of the inputs:

Starting Station: Set starting station of the file. If stationing is disabled (accessed by Project Info button), this entry will not appear. When the Auto Start Distance Project option is selected (accessed by Project Info button), this value is automatically specified based on the ending distance of the previously-collected file.

Starting Distance (ft/m): This value is the distance used as the starting distance in the output file containing dielectrics and % voids. If stationing is being used, this value is 0-99.9. When the Auto Start Distance Project

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option is selected (accessed by Project Info button), this value is automatically specified based on the ending distance of the previously-collected file.

Decreasing Distance: When this box is checked, the distance values decrease as the data are being collected.

Lane: This user-specified information indicates the lane from which the data collected. Select the lane from a dropdown list of available names.

Lateral Offset (ft/m): This field is the distance of the center of the cart from the Lateral Offset Reference. It is recorded in the output file. It is critical to input the distance from the same reference line within the same project (See 3.1.9). If you have to change your reference line for any reason you need to create a new project. The distance is negative if you are left of the reference line when looking in the increasing stationing direction and positive if you are right of the reference line (this will be changed to left and right for future releases of the software).

Lot: Optional entry. This is a user-specified information that indicates the Survey Lot, which is one of the filter options in the Playback Range menu.

Sublot: Optional entry. This is one of the filter options in the Playback Range menu.

File Root Name: The first part of the output filename. It is recommended to start the filename with the 3 digit route # followed by an underscore and the 1 digit lift number (note that lift number will be part of the inputs in future releases of the software). Various other filenames will be employed as part of Chapters 4, 5, and 6, but this should be the root filename for all tests conducted on the given route.

o No action is needed when multiple measurements are made since all files have numbers appended to them that increment from file to file. For example, of the root name is 061_1, the first file will be “061_1_001 Export Data”, the second file “061_1_002 Export Data”, etc.

The four tabs, at the bottom of the File Information page, allow user to a) return to the Project Information page; b) playback and review the most recent file; c) adjust the characteristics of the displayed charts; and d) initiate a new data collection file through the Collect Data button. Press Collect Data to go to the page that allows the user to collect data.

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The Collect window shown in Error: Reference source not found 3.23 is opened by pressing the Collect Data button in the Sensor Calibration page.

Figure 20: RDM software: Data Collection page (23)

The system offers three data collection methods discussed below. The user should select one of the proposed methods to commence the data collection session:

o Collect Dist: This collection method makes use of the DMI, and it is ideal for routine data collection explained in Chapter 5. If this option is selected, the collection will be triggered by the DMI and will continue as long as the wheel is moving forward.

o Collect Time: Pressing Collect Time initiates collection of a continuous file at a rate of about 60 measurements per second. This mode is ideal for static (non-moving) measurements at a specific location. It will be employed as a spot test, typically on areas marked for core tests.

o Collect Core: Pressing the Collect Core button will start data collection of a 4 ft (1.2 m) file using a survey wheel. This feature is not recommended by MnDOT at the moment, but will be modified to allow for time-collect mode in future releases, which will make it employable as part of this protocol. Some states (e.g. Alaska, Ohio) have found that the Collect Core 4’ distance files give better calibration data than the stationary Collect Time files, when using field cores to calibrate the PaveScan. The RDM 2.0 Collect Core will be based on input from multiple states to allow for a robust core measurement. Since the core validations are such a critical part of the process it is currently

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recommended to collect both distance and time collect mode at each core location. It is anticipated the distance collect will have multiple options in addition to the 4 foot test as well as a procedure that lines the user up without having to measure it out.

The measured dielectric values will be displayed in real-time on the screen of the computer throughout the day of paving. The PaveScan software offers three data visualization options: Heatmap, Linechart and Histogram. During testing, the software displays two of the proposed charts based on user’s choice. An example of the data visualization page is shown in 3.24. You should ensure that data is showing up on the screen as you collect. If not, something went wrong with your setup. If data does show up properly, you are most likely set up properly and ready to collect data throughout the day according to Chapters 4 through 6. The next section gives brief guidance on what to do at the end of the paving day.

Figure 21: Data collection mode with collect distance chosen.(24)

3.1.11 Post-Paving ProcedureOnce the user is finished testing for the day, the equipment should be packed into your vehicle, brought back to your office or on-site location. Once back to the storage location, the data needs to be exported and the equipment needs to be stored properly in the same way it was when you initially setup the equipment. This includes making sure that the tablet, concentrator box batteries, and GPS equipment are all left charging overnight. The procedure below shows how to export the data properly, similar to how it is done for puck dielectric to AV% testing:

Insert the USB on the right side of the Tablet and select PLAYBACK on the Main Menu of RDM (see Figure 3.25)

Choose the Group and Project you wish to export (the whole project will be 33 | P a g e


exported, so there is no need to specify a file). Select EXPORT PROJECT to continue.

Wait while the Tablet loads all the files, this may take a minute. When the loading bar in the top right corner says Export Complete, return to the Main Menu and Exit the program.

Figure 22: Preparation to export the puck testing results. (25)

Go into File Explorer ―> Documents (or use the shortcut on the Desktop). Double click on the PaveScan Exports file. Select the Project you are exporting, the name will be the Project Name you set up for the day (ex. TH61_L1_2019-09-16). Copy the entire folder and paste to the USB Drive. The files will have the date and time of export if you are unsure. Typically there will only be one project name per day, but complete this operation for all Project Name designations you used that day.

You have now successfully exported the data collected for the day. This data will be processed by MnDOT if you send it to them, or according to the steps outlined in “Chapter 8: Analysis and Reporting Procedures.”

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