The Worldwide Leader in Concrete Paving Technology
The GSI®– GOMACO’s Non-Contact Profiler
Paver-Mounted, Work Bridge-Mounted or the GSI Machine
• Data gathered is used to produce
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commercially known profilograph
indexes.
• Printout of surface smoothness
includes station or footage
reference from starting station, job
information, bump location, and
profile index numbers.
What additional features does
the GSI machine have
available?
• The GSI machine can be used to
check the accuracy of stringline
setup before the actual paving
takes place.
Slope Sensor • Checks accuracy of the sub-grade
to obtain maximum yields and
determines potential smoothness
of the final slab before paving
(based on the sub-grade).
• Provides the ability to study the
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Sonic Sensors smoothness of the slab during the
curing process for future research
on mix designs.
Two paver-mounted GSI units provide instant rideability results on Interstate 75, near Pinconning, Michigan. • The GSI machine’s automated
steering capability guarantees the
What is the GSI? traces or four lanes in one pass. The • Locates irregularities (localized highest repeatability and accuracy
• A non-contact surface smoothness readings are from a six inch (152 mm) roughness) in the slab that need to be in the industry.
instrument that is so versatile it footprint to simulate the true picture corrected and records that location
provides multi-application usage. of the tire contact area on the through the use of a distance tracking Who would want to use the
• The GSI includes: GSI computer pavement. The information gathered encoder. GSI?
assembly, real-time graphic display, by the sensors in each trace establishes • Paving contractors
• Concrete surface can be repaired while
media storage card, two sonic sensors, a measurement of the slab. • Flat floor slab contractors
still in the plastic state.
slope sensor, distance counter wheel • Consulting engineering firms
assembly, and cables.
What can the GSI do? • Can read multiple traces • DOT (Department of
• Provides immediate data to make on- simultaneously with the addition of Transportation)
How is it done? the-go adjustments, if necessary, to more instruments. • Federal highway authorities
• Three different sensors, two sonic and assure maximum smoothness results.
• Smoothness readings can be seen • FAA
one slope, read the smoothness data in • Gives immediate graphic display as to before saw cuts are made for joints
the wheel tracks (or anywhere on the smoothness of the surface. and tining or the texturing of the slab.
surface of the slab) on up to eight
In today’s competitive concrete paving market, with increasingly stringent rideability
requirements, GOMACO offers a tool to help you achieve maximum paving results...
the GOMACO Smoothness Indicator (GSI®).
The GSI, operating as paver- derived from the true profile of the quality of your ride. Instant results
mounted, work bridge-mounted, or the surface, determined by the data eliminate having to wait until the
independent GSI machine, has the collected. These indexes are viewed cured concrete has been
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ability to monitor and report your and monitored on the GSI’s seven inch profilographed, to see how the ride has
smoothness readings to you instantly. (178 mm) diagonal, touch-screen been affected by the variables.
It’s the ultimate quality-assurance tool monitor. The touch screen, with
available on the market today. adjustable mount, allows optimum
The GSI has the ability to read up viewing.
to eight traces in a single pass, directly The on-the-go surface smoothness
behind the paver. The real-time information includes station and
information collected creates the GSI footage documentation for later
number, or an instant rolling average of reference of bump and smoothness
the surface smoothness readings. The locations. The GSI’s bump alarm can be
GSI number is relative to the IRI set with project parameters. If a bump,
(International Roughnesss Index) localized roughness, occurs during
number, but created within a much paving that is out of parameter, a bump
shorter paved distance. That distance warning is displayed and the bump’s
can be adjusted by the operator. Along station location is marked on the graph
with the GSI number, two other for exact reference.
indexes are also calculated continually, The GSI’s feedback allows on-the-
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the PI or profile index, which is based go adjustments to fine-tune the paving
on the California profilograph, and the operation. You instantly know how
IRI. The information can also be changes to a number of different GSI units can be mounted to GOMACO Spanit® work bridges. In these photos, the
exported as an .erd file. The indexes are paving variables directly affect the work bridge is attached to the back of a GOMACO GHP-2800 slipform paver.
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The GSI machine follows a GOMACO GP-4000 paver, right behind the finishers, on the Central Texas Turnpike. The GSI takes smoothness readings simultaneously from
four different traces and uses the data to establish a measurement of the slab.
Screen shots taken during the paving process illustrate the many different screens
and the variety of information available, at the touch of a fingertip, on the GSI’s
touch-screen display.
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Part of calibrating the system is entering This stretch of roadway posted some good
job-site information into the GSI’s computer. numbers on the IRI index.
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Two different sensor traces can be displayed The GSI provides ride numbers for three
on the computer’s screen at a time. different indexes with this set-up screen.
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A trace shows how this section of roadway Sensor positioning has to be measured out so Two paver-mounted GOMACO GSI units monitor the smoothness in each driving
did using the two-tenths blanking band. the GSI computer knows what it’s measuring. lane. The information is instantly displayed and reviewed on a single touch screen
mounted on the side of the paver.
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The GSI display, mounted at eye level on
the side of the paver, offers a variety of
The paver-mounted GSI was a powerful diagnostic tool as a contractor worked in GSI units mounted to a GHP-2800 viewing options of the information
Alabama to fine-tune their paving process for a challenging rideability specification. profile new Interstate 69 in Indiana. collected by the GSI.
Paver-Mounted GSI® – technicians to identify needed auto repairs. processes. Changes were tracked on the
Immediate smoothness readings The following are some published The current state of practice is to cautiously GSI’s Event Log, which allows
are available with the GSI on-board observations and results on how well make an equipment/process change and important events such as sensitivity
your paver. The paver-mounted GSI is a the GSI performed in the study... wait approximately 24 hours for feedback changes, draft changes and more to be
cost-effective quality control tool that is The consensus among the contractors when the hardened pavement can be marked on a graph. The entire list of
quick and easy to install on your was that the GSI’s real-time smoothness profiled. With the GSI, the process marked changes can be reviewed. Then,
GOMACO paver. Since it’s on-board measuring technology represents a valuable becomes instant. the instant feedback from the GSI
the paver, any interference with the rest quality control tool. Examples of intentional On a paving project in Alabama, a showed them what each change was
of the paving train or finishing crew is process changes that can be evaluated GOMACO contractor equipped their doing to their concrete. They knew
minimal. It also has the capability of include: two-track GP-2600 with two paver- right away if the change had improved
reading multiple traces, from one to • Equipment adjustments mounted GSI units. Strict ride their quality or hurt it. No 24-hour wait
eight. -Paver speed specifications allowed no room for was involved before a profilograph
GOMACO is experiencing an -Vibrator frequency error, so they spent three days fine- could be run on the new concrete
increased demand for the paver- -Sensitivity of paver evaluation tuning their paver and their paving roadway.
mounted GSI as a tool for checking controls
rideability on-the-go. -Oscillating correcting beam frequency
The effectiveness and quality of the -Numerous others
GSI has been verified by contractors on • Process changes
projects around the world and by -Concrete workability
independent studies. The GSI recently -Concrete dumping/spreading
completed a three phase research procedures
project by The Strategic Highway -Stringline tension
Research Program (SHRP2) for the -Hand finishing techniques
Transportation Board of the National -Mixing time
Academies. The study, in phase one, set -Stopping the paver vs. slowing the
out to identify real-time smoothness paver
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measuring technologies for concrete -Numerous others
paving. Phase two and three consisted The report also goes on to say that the
of field demonstrations and GSI is also a powerful diagnostic tool;
evaluations. similar to equipment used by automotive A paver-mounted GSI unit provides immediate monitoring to assure proper paver
setup and performance or examine for corrective measures that need to be taken.
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The GSI Grade Analysis Tool builds a profile of the grade and estimates the concrete yield of the project.
GSI® Tools™– Grade Analysis
A GSI trace over a prepared grade for paving can provide a complete grade analysis with our GSITools
software. This software provides a cut and fill report for final grade preparation and can build a profile of the
grade to estimate the concrete yield of the project.
The following is an overview of the Grade Analysis Tool features:
• Grade Analysis Report
Selected profiles ❘ Trace details ❘ Slab volume ❘ Project parameters ❘
Grade cut/fill summary ❘ User selected graphs
• Project Trace Selection
Add/delete reference (stringline or stringless) traces ❘ Add/delete wheel path
traces
• Project Parameters
Slab definition ❘ Grade cut/fill parameters ❘ Sensor positions ❘ Grade offsets
• Table View
Elevation data ❘ True profile data ❘ Grade cut/fill details ❘ Grade cut/fill
summary
• Graph View
Elevation ❘ True profile ❘ Grade cut/fill details
GSI®– Survey Tool
With the GSI Survey Tool, a GSI trace
over an existing roadway can provide
data for a 3D model in an overlay
application. The GSI will collect the
data with multiple traces (up to eight)
in a single pass for the pave model.
The GSI operates with a prism
mounted to the machine and a Total
Station located on a hub. This data
collection provides Eastings,
Northings, and Elevations for the
pave model. This single pass with the
GSI on a project totally eliminates the
tedious handwork of two survey
engineers and provides an accurate
visualization of an existing roadway
for a 3D model to be used for
stringless paving of an overlay
project.
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The GSI profiles the grade with 3D
stringless controls. Each trace collects
the X, Y, and Z positions needed to
create a true 3D map of the terrain.
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The GSI in transport mode easily Lightweight, modular GSI® Machine Specifications:
travels around the job site. truss frame. Engine: 4024T John Deere diesel engine,
60 hp (44.8 kW), Tier 2.
Frame: Pin-connected main frame.
Standard frame length is 30 ft. (9.14 m).
Slope sensors are located
Automated Steering Control System:
between each of the two
Electronic/hydraulic forward and
outside sensors.
reverse steering control system. Control
panel with monitor gauges.
Real-time graphics display
Hydraulic Leg Assemblies.
of smoothness trace.
Four Wheel Suspension: Hydraulically
driven, all wheel steering, wheels turn
90 degrees for loading or moving the
machine.
Tires: Solid rubber tires, 28 in. (711 mm) x
9 in. (229 mm) R15 in. (381 mm) wheel.
Steering: All-wheel steer.
a. Coordinated four-wheel steer
(operational & transport mode)
Hydraulic elevation control
b. Crab-steer (operational & transport
accommodates slab heights
mode)
up to 18 in. (457 mm). Frame
c. Front-steer only (operational &
height extension available for
transport mode)
up to 30 in. (762 mm) slab
d. Rear-steer only (operational &
thickness.
transport mode)
e. Counter-rotate (operational mode)
f. Stringline steer (operational mode)
GSI sensors trace the wheel tracks for reading smoothness GSI Computer Assembly: includes
data for up to eight traces or four lanes in one pass. Readings real-time graphics display, computer
Printer provides an
are from a six inch (152 mm) footprint to simulate the true assembly, media storage card.
instant printout of
picture of the tire contact area on the pavement. (Illustration Four Wheel Track Sensor Assemblies:
surface smoothness.
above is set up to trace two lanes or four wheel tracks) includes eight sonic sensors, slope
sensors, mounting brackets and cables.
Sensors trace the wheel tracks for
Heavy-duty, industrial reading smoothness data for two lanes.
puncture-proof, solid tires. Operators Platform: includes seat
assembly.
Emergency Stop Switches.
Worldwide Headquarters European Headquarters
GOMACO Corporation GOMACO International Ltd. is located Cover Photos: HW-111106 D2, CO-101108 D5 and HW-040813 D12
PO Box 151 in Witney, England. GOMACO Corporation reserves the right to make improvements in design,
Ida Grove, IA USA 51445 Sales offices are located in Singapore, material, and/or changes in specifications at any time without notice and
Ph: 712-364-3347 Bolivia, Australia, China and India. without incurring any obligation related to such changes. Performance data
The Worldwide Leader in Concrete Paving Technology www.gomaco.com GOMACO has a worldwide distributor is based on averages and may vary from machine to machine.
E-mail: info@gomaco.com network for sales and service. Printed in U.S.A. © 2012 (05 Printco 5000) Order #0405-0A10353
You can always find us at: GOMACO Corporation
GOMACO Corporation's Quality Management System Is
www.gomaco.com/gsi ISO 9001:2008 Certified By The American Systems Registrar.
MANUFACTURED UNDER ONE OR MORE OF THE FOLLOWING U.S.
OR FOREIGN PATENTS: 5,190,397; 5,209,602; 5,924,817; 5,941,659;
Quality Policy: We Shall Meet Or 6,099,204; 6,450,048; 2,211,331; 2,069,516; 7,044,680; 7,284,472; 7,517,171;
Exceed Our Customers’ Expectations. 7,845,878; 7,850,395; AND PATENTS PENDING.
