Guntert & Zimmerman
Construction Profiles
Fall 2011
EquipmentPaving Stringless Update
When Stringless is Friendly A contractor finds that his stringless concrete paving system is easy to use. With just a few days of training, Hawkins
the stringless technology improves paving
Construction Co. is up and running with
production. “Trucks can cycle through the site
stringless concrete paving technology.
faster, because there’s no stringline,” he says.
“We’ve had minimal training with it,” says Ron Mockelman, Paving Equipment Manager
Although only two robotic total stations are
for Hawkins, based in Omaha, Nebraska.
required to control the four-track G&Z paver,
“We pretty much just dove into it. A lot of
Hawkins has chosen to pave with four total
companies would have bought more training
stations. With three total stations used for
than we did, so I think we’re doing pretty well
actual 3D machine control, Hawkins is able
and it’s only going to get better.”
to leap frog the total stations allowing for zero downtime. A technician back-sights each of
This year Hawkins started running stringless on
the three robotic total stations to three known
two Interstate highway paving projects – with
control points. That fixes the location of the
a total contract value of $78 million USD –
total station relative to the digital terrain model
located on I-80 between Omaha and Lincoln,
that is contained in the computer on-board the
Nebraska. We visited Hawkins in mid-July,
paver. The fourth total station stays behind
when the company had completed paving
the paver, to check the pavement surface as-
more than half of one I-80 project: a 6-mile,
built, and to do any diagnostics that might be
60-foot-wide stretch of 13-inch-thick concrete
needed for ride quality.
pavement – all with no stringline. The robotic total stations can then read the Hawkins elected to buy the NoLine: Stringless
location of the paver by seeing two prisms
Preparation Kit from Guntert & Zimmerman.
mounted on masts above the paver. The
The contractor now owns two G&Z pavers,
prisms have a precise spatial relation to the
an S850 and the new S600 concrete paver,
conforming pan of the concrete paver. Then
and both are fitted with the NoLine kit. “We
the total stations relay that location information,
invested a substantial sum for the set-ups
by radio waves, to the computer on-board
for two pavers, four robotic total stations, an
the paver. The computer compares the actual
on-board computer/monitor and a stringless
location of the paver to the design location in
trimmer,” says Todd Allen, a Hawkins
the model, and makes adjustments in northing,
superintendent. The robotic total stations and
easting and elevation of the paver.
on-board computer are manufactured by Leica Geosystems, and come ready to “plug-and-
When we visited the I-80 project, the Guntert
play” for the G&Z pavers.
& Zimmerman S850 was paving 24 feet wide to form two driving lanes. Dowel baskets for
“We decided to make the switch to stringless
concrete joints were set at 16.5-foot intervals.
to improve our speed and efficiency, and
A second 24-foot pass, adjacent to the first,
to shrink our labor costs,” Allen said. And
would follow to form a third driving lane and a
that’s not to mention the human error that
12-foot tied concrete shoulder. On the opposite
occurs when a truck hits a stringline or
side of the driving lanes, Hawkins would then
somebody breaks the string. What’s more,
pave a 12-foot shoulder separately. The new
we get improved access to the site and more
pavement widened the old one from two
choices in how we pave.” Mockelman says
driving lanes to three and a concrete shoulder.
“Our smoothness results with the stringless
simply add or remove inserts to change paving
Both Allen and Mockelman said G&Z’s NoLine
system are better than we have averaged
widths. The tractor frame and the paving
stringless system using Leica equipment
with a stringline,” says Allen. “But we’re just
kit telescope in and out together to change
is easy to use and friendly to learn. “We’re
scratching the surface of what we can do.
widths.
cross-training three or four different guys on
Mockelman said Hawkins has put up actual
the crew,” said Allen. “And we find that with
profilograph readings as low as 2 inches of
The fast width change is an idea that Hawkins’
absolutely no computer experience they can
deviation per mile from a one-tenth (of a foot)
Terry Kirsch and Mockelman had, and
set the system up and they’re competent to
blanking band.
Guntert followed up. “Guntert designed it
run it within a week to a week and a half.
and engineered it for us and got us what we The Nebraska Department of Transportation
wanted,” says Mockelman. “We could take this
Getting the stringless system ready to pave
awards incentive payments for extra-smooth
24-foot paver and drop 4 feet out real quickly
in the morning takes about 45 minutes,
pavements. For 0 to 4 inches of deviation the
and pave a 20-foot ramp without having to
Mockelman says. “In the morning we attach the
contractor gets 106 percent of pay; for 4 to 8
disconnect the paving kit.”
computer monitor and the three radios to the
inches the incentive payment is 104 percent and for 8 to 12 inches it’s 102 percent of pay.
paver,” he says. “There are five connections. “They’re very reliable pavers,” Allen says. “We
There’s a power connection, and the two slope
hardly ever have anything go wrong with them.
sensors are tied into one connection, plus the
“Both of our Guntert & Zimmerman pavers
And the support we get from Guntert is top-
three radios. Then you put your machine in 3D
are fantastic machines, for ride quality and
notch.”
mode, turn the monitor on, pull up the project
maneuverability,” says Allen. “They’re like having a Cadillac instead of a Chevy.”
file to the screen, and the paver is ready.” Mockelman agrees. “Guntert’s service has been excellent,” he says. “From my experience
“Then we back-sight the robotic total stations
“We like the different steering modes on both of
it’s probably the best service in the concrete
to three known control points,” Mockelman
our G&Z Pavers,” Allen says. “You can crab-
paving industry.”
says. “Three points give you a tighter re-section
steer the paver, and you can turn it in a circle
on your total station. The total stations can
within its own length. The paver can move
Prior to paving, subcontractor Koss
calculate where they’re at on the job. Now they
sideways out of a pour, which is fantastic for
Construction milled the old asphalt from
can relay that information to the paver. We set
tight locations. The maneuverability of these
the underlying concrete pavement, said
up three total stations in the morning, and a
pavers lets us use a four-track paver where
project superintendent Kurt Gregor. Another
fourth one to run the check on the slab.”
somebody else would normally use a two-track
subcontractor, Pink Grading, broke the
paver.”
concrete and graded the dirt in preparation for
We asked Mockelman what the biggest
lime stabilization. Hawkins stabilized the earth
challenge of the project is. “Right now our big
Mockelman appreciates the ability of the
subgrade with lime, and Recycled Materials
push is to get this Greenwood project finished
Guntert & Zimmerman S850 to change paving
Co., Arvada, CO, crushed the old concrete
so that we can get to the second I-80 project
widths to increments between 20 and 26 feet
on grade. A motor grader spread the crushed
and pave the mainline on it,” he said.
without dropping the paving kit out. Instead
concrete, and Hawkins trimmed it with a
of a two-day job on other pavers it’s a two to
stringless trimmer.
three-hour job on the S850. A contractor can
Equipment Airport Paving Update
Dufferin Construction Selects G&Z Spread For Canada’s Longest Runway To build what will be the longest airport runway in Canada, Dufferin Construction Company, a division of Holcim (Canada) Inc. recently purchased a three-machine spread of concrete paving equipment from Guntert & Zimmerman. Ontario-based Dufferin Construction , which already owns two other G&Z pavers, bought an S1500 four-track Slipform Paver, a PS1200 Placer Spreader, and an TC1500 Texture Cure Machine for this project. The big project is at Calgary International Airport in Alberta, where Dufferin’s contract calls for more than 1 million square meters (1.2 million square yards) of new concrete surface. Construction has already started. Dufferin essentially will have two construction seasons – 2012 and 2013 – to complete the work, which is scheduled to wrap up by May 2014. According to project superintendent, Mike Cristinziano, the project’s challenge is to place and pave the sheer volume of aggregates and concrete required. “You need to take into consideration that our construction season up here in Calgary is not as long as in other parts of the country,” says Cristinziano. “Depending on the weather, our season runs from May or June until October, and that’s it.” It is possible that construction will run around the clock, and seven days a week, in order to finish on time, says John Zavarella, superintendent of concrete plants and equipment for Dufferin. Both he and Cristinziano say working hours will depend on how things go and how well the weather cooperates.
Project Specifications:
•
A new runway that is 4,300 m long by 60 m wide (14,100 ft. by 197 ft);
•
Apron area measuring 145,000 square meters, or 173,000 square yards;
•
Two taxiways, each 3,800 m long by 25 m wide (12,500 ft. by 82 ft);
•
Six high-speed taxiways;
•
Base aggregate, 1.5 million metric tons, or 1.65 million U.S. tons;
•
Cement-stabilized base, 200,000 cubic meters, or 262,000 cubic yards.
The concrete for runways and taxiways will be 435 mm thick, or 17.1 inches. Apron concrete
Zavarella says Dufferin crews and operators appreciate several features of the G&Z pavers and equipment:
will be 415 mm, or 16.3 inches thick. • “We have owned G&Z S1500 paver since 1995, when we built Highway 407 in Ontario,”
start of the day with ease. Handwork is minimized. •
says Zavarella. “That machine is still in use as one of our main paving units. In 2001, we
G&Z’s New TeleEndXL: Telescopic End Section allows quick width changes between 12.5 m and 10 m wide which will be frequent during the duration of this project.
•
added an S850 to our fleet. So our crews and
All three machines – the paver, the placer and the texture cure machine – have 90 degree steering capability. Each machine can turn the tracks 90 degrees and move directly across to
operators are well experienced in operating Guntert equipment.
The paver has split guillotine side gates that allow the paver to back onto existing slabs at the
the next slab. •
The PS1200 allows Dufferin to place dowel baskets well out in front of the paving train. And the placer spreader has a 64-inch belt that slides in and out for faster operation than one that
“When we were looking at the Calgary site, it called for paving 12.5 meters wide at the widest, and for paving at that depth we knew that the S1500 was pretty well the right machine. We have already tackled airport jobs of that width with that type of pavement and we had no issues with it.” Cristinziano says Dufferin likely will run two pavers – the S1500 and the S850 – on the Calgary airport project. The S850 will handle narrower widths and shorter stretches of pavement. “We strive to be leaders in the concrete paving business,” says Zavarella. “Our crews and operators all take pride in achieving good quality. That’s one reason we selected paving equipment from Guntert & Zimmerman.”
folds up and down. “We can place concrete a lot faster and more efficiently,” says Zavarella.
Guntert & Zimmerman Const. Div., Inc. 222 E. Fourth St. Ripon, CA 95366 U.S.A. Phone +1 209-599-0066 Fax +1 209-599-2021 Toll Free 800-733-2912 (USA / Canada) Email: gz@guntert.com Web: www.guntert.com
Construction Profiles is published by Guntert & Zimmerman to inform readers of applied construction technology utilizing Guntert & Zimmerman equipment. All rights reserved. The contents of this publication may not be reproduced either in whole or in part without the consent of Guntert & Zimmerman. Printed in U.S.A. Manufactured under one or more of the following U.S. or Foreign Patents: 4,433,936; 4,483,584; 0051885; 6,390,727; 6,390,726; 6,176,643B1; 5,135.333 and 117323 and Patents Pending. Some items shown may be optional. G&Z reserves the right to make improvements in design, material, and/or changes in specifications at any time without notice and without incurring any obligation related to such changes. Brochure No. 400P117