Best
Practices
Dennis Clausen
Director of Training
GOMACO Corporation
Considerations for Profile Paving
Stringline Installation &
Maintenance
Subgrade Stability and Accuracy
Concrete Control & Placement
Paving Basics
Finishing Operations
Other Considerations
Stringline Installation & Maintenance
Setting & Maintaining Accurate
Stringline
 Recommend 25’ Surveyed Stations and Stringline Stakes,
Closer Intervals in Horizontal and Vertical Curves.
Stringline Installation & Maintenance
Setting & Maintaining Accurate
Stringline
 Recommend 25’ Surveyed Stations and Stringline Stakes,
Closer Intervals in Horizontal and Vertical Curves.
 New Condition Cord, Wire, or Cable.
 Daily Maintenance & Checking of Stringline Elevation and
Alignment.
 Daily Maintenance on Stringline Tightness.
Subgrade Stability
 Stability of Paving Grade
 Unstable Grade Causes Thickness Control Problems if
Haul Trucks are Placing Concrete on Grade.
 Possible Profile Problems if Subgrade continues to Move.
Subgrade Stability
 Stability of Paving Grade
 Unstable Grade Causes Thickness Control Problems if
Haul Trucks are Placing Concrete on Grade.
 Possible Profile Problems if Subgrade continues to Move.
Stability of Track Line
 Track Line Failure may Occur Causing Profile Deviations.
Subgrade Stability
 Stability of Paving Grade
 Unstable Grade Causes Thickness Control Problems if
Haul Trucks are Placing Concrete on Grade.
 Possible Profile Problems if Subgrade continues to Move.
Stability of Track Line
 Track Line Failure may Occur Causing Profile Deviations.
Stability of Haul Road
 Safety
 Important because of Possible Delays in Concrete
Delivery.
 In Extreme Cases may Affect Paver Track Line Grade.
Subgrade Accuracy
Accuracy of Paving Grade &
Trackline.
 Fewer Changes in Elevation by the Paver, the higher
probability of good profiles.
 Accurate Grade Elevation Makes Concrete
• Placement More Consistent.
Placing With Transit Mix
Considerations if Transit Mix Must be Used

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Plant Should be Central Mix if Possible
Mixer should be Designed as Paving Mixer
Chutes Must be Kept Clean
Control of Clean-out Water Must be Monitored
Position and Placement of the Truck Mixer is
Critical
Placing Central Mix Concrete
Positive Factors of Central Mix Placement:
 Most Efficient Mixing System, helping make a more consistent mix.
 Faster to Unload End Dump & Bottom Dump Trucks.
 Use of Placers & Placer Spreaders May:
 Allow the Paver to Move at a Consistent Rate of Speed.
 Allow the Paver to Operate with a Consistent Head of Concrete.
 Eliminate Large Piles of Concrete, which vary loading on the paver.
 Require Close Monitoring if Concrete Slump varies or if Subgrade is no
Accurate
Paving Basics
Paving Basics
For A Paver to Perform at Optimum it
Must be:
 Paving Form Must be Clean
 Designed for the Width to be Paved
 Maintained According to the Manufacturers
Recommendations
 Assembled and Adjusted to the Manufacturers
Recommendations
 Operated by Trained Personnel
 Operated by Motivated Personnel
 Paving Crew Must Operate as a Team
 Paving Team must have Pride in Their work
Extrusion Type Paving Form
 Must be Properly Adjusted for Good Paving Results.
 Establish a Set-Up Procedure and Follow it Religiously.
 Pan Should be Straight & True, Left to Right & Front to
Rear.
 For Good Profile Results, Pan Should be Set Parallel to
the Stringline Front to Rear.
 Check the Profile Pan for Accurate Setting after:
– Width Changes
– Moving the Machine
 Replace or Repair Damaged or Worn Parts When
Necessary.
Finish Procedures
 Good products
Finish Procedures
 Good products
 Check product dimensions
Finish Procedures
 Good products
 Check product dimensions
 Problem areas
Finish Procedures
 Good products
 Check product dimensions
 Problem areas
 Start and finish headers
GSI The Contractor’s Tool
Before Paving
Check smoothness of the sub-grade
Check smoothness of the stringline
setup
Calculate yield of the paving materials
based on sub-grade and stringline
setup
Pin point areas of cuts and fills in the
sub-grade
Stringline Sensor
GSI Tools
Analysis Software
Sub base analysis for McCarthy
Improvement in South Carolina
With the GSI you can collect the
same sub grade measurements
every 2 inches
GRADE CUT/FILL DETAILS
STATION REFERENCE
DEVIATION HEIGHT
ROW INTERVAL
RESOLUTION
– 2”, 6”, 1’, 12’, 25’, 50’,
100’, ect.
COLOR CODED CUT
AND FILL
PARAMETERS
– BLUE = FILL
– RED = CUT
SLAB VOLUME
NOMINAL SLAB VOLUME
VOLUME DEVIATION
THEORETICAL VOLUME (NOMINAL + DEVIATION)
REPORT
JOB INFORMATION
TRACE DETAILS
SLAB VOLUME
PROJECT
PARAMETERS
GRADE CUT/FILL
SUMMARY
USER ADDED GRAPHS
KNOWN FILE FORMAT
FOR SHARING
INFORMATION AND
PRINTING
– (*.HTML FILE USES INTERNET
EXPLORER FOR VIEWING AND
PRINTING)
GSI The Contractor’s Tool
During paving process
Provide paving crew immediate
smoothness readings right out of the paver
– Corrections may be made to the pavement
surface while concrete is still in plastic condition
– Adjustments can be made to paving operation
before thousands of feet have been paved
Separate machine can be backed over the
repaired surface to take readings again
Check Profile of Poured Concrete
Behind Paver
Check Profile of Poured Concrete
Behind Paver
Check Profile of Poured Concrete
Behind Paver
Check Profile of Poured Concrete
Behind Paver
View 2 Traces
View Report in PI or IRI Format
3D Stringless Control System for
Curb & Gutter, Trimming & Concrete Paving
What is Stringless 3D?
A 3D Machine Control system that simplifies jobsite logistics,
reduces costs and improves quality and safety
 Removes stringlines and pins from the jobsite

Removes install, maintenance & removal costs

Increases working safety, especially at night
 Puts the 3D job design directly onto the machine

Eliminates setting-out errors and stringline influences

No waiting for setting-out before production

No dependency on setting-out – work wherever you have 3D data

Increases productivity, quality and performance bonuses
 Controls height, slope (and steer) of machines
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
Delivers a precisely-constructed product

Optimises amount of new material needed

Reduces over-trimming, overpouring

Improves concrete yields and material cost savings
Working with Stringline…

Inspect design – calculate setting-out lists for each lane

Setup a theodolite, survey each hub or pin position with total station (or GPS if accuracy isn’t important!)

Hammer (or drill) in each pin, minimum 1 line for each lane of concrete/asphalt

Check pin alignment & adjust if required

Survey and set stringline height on each pin (min. 2 men)

Install & tension clamps and stringlines
Reference
Point

“Eyeball” & adjust stringlines before paving

Move machine into position, set sensors to stringline

Check machine position relative to stringlines

Start Production, monitor machine position

Ensure (or hope!) nothing disturbs or damages stringlines during paving/milling…
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Walk left 5ft!
Walk right 1ft!
Up a bit!
Down a bit!
STOP!
Reference
Point
Mainline Slipform Paving &
Fine-Grade Trimming with Stringless 3D
Click to return to Main Menu
Why go “Stringless”?
Could your paving projects benefit from…
 …no marking-out and drilling to setup pins and guidewires?
 …easier paving in “zero clearance” situations, e.g. bridge decks,
urban streets, railway cuttings, tunnels, narrow motorway lanes?
 …no special access/safety equipment to pave in tunnels?
 …no pre-production planning – just arrive, pave anywhere, any time?
 …no human error from stringline setup?
 …no inaccuracy of “field model” compared to original “office design”?
 …lower material costs, improved concrete yield (less waste)?
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Why go “Stringless”?
Because stringlines…
 … are expensive, time-consuming and error-prone to install
 … can be easily damaged during paving
 … can be easily misaligned
 … can be a significant site safety hazard
 … interfere with site logistics, increase concrete delivery
time, haulage costs, and reduce productivity.
 … require pre-production planning & increase survey effort/cost
 … don’t always “model” the designed surface accurately
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What is 3D?
A 3D Machine Control system simplifying slipform jobsite
logistics, reducing cost, improving quality and productivity
 Specifically designed for mainline (slab) pavers & trimmers
 The result of 16 years worldwide experience in 3D slipforming
 Developed in close cooperation with GOMACO
 Eliminates stringlines (“stringless control”)
 Controls paver elevation, steer, slope and draft
 Constructs directly from the 3D plans
 Removes need for stringline set-out crew
 Minimises pre-production planning and preparation
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Stringless System for Gomaco Trimmers
System Components
Reference
Point
Reference
Point
Prism
Machine
Computer
Radios
Slope
Sensor
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Theodolite #1
(Guidance)
Theodolite #2
(As-builts &
Leapfrog)
Stringless System for Gomaco Placer/Spreaders
System Components
Machine
Computer
Radio
Slope
Sensor
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GPS or Prism
GPS Reference
Station
Stringless System for Gomaco Pavers
System Components
Prism
Machine
Computer
Reference
Point
Prism
Radios
Slope
Sensors
Reference
Point
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TPS #3
(As-builts &
Leapfrog)
TPS #1
(Guidance)
TPS #2
(Guidance)
Faster, more accurate trimming…
Optimal subgrade saves concrete and improves rideability
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Smoother airfield paving…
Increases runway life, reduces undercarriage & tyre wear
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Smoother road paving…
Increases road life, reduces vehicle wear & passenger fatigue
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Practical Issues…
In the field!
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Practical Issues
Checking concrete (or subgrade) level and position
 The third theodolite together with
a prism measures the surface
“as-built” behind the machine
 Errors (and adjustments)
shown on theodolite
 Report stored on 3D computer
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Practical Issues
Adjusting the Machine
 If the level needs
adjusting…
 …just like stringline control
we can adjust all leg
heights,
and draft independently,
without stopping paving
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Practical Issues
Adjusting the Machine
 If position needs adjusting…
 …just like stringline control
we can adjust position at
front and rear independently,
without stopping paving
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Practical Issues
Moving the Theodolites (‘Leapfrogging’)
 Maximum Range Theodolite-to-Paver is <= 200m (*depends on conditions)
 We don’t want to stop the paver for too long!
 Before maximum range is reached, move 3rd Theodolite to new position &
setup (Position & Orientation Fix).
 Press ‘Swap Theodolite’ on computer
 System switches control from #2 (or #1) to #3 Theodolite automatically
 Move ‘old’ Theodolite to new position, setup and repeat procedure
 Ensure enough Reference Points visible for Setup (Position & Orientation Fix)
* - temperature, humidity, air quality
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Questions?
Dennis Clausen
Director of Training
GOMACO Corporation