GOMACO World Index --- GOMACO World 38.1 - July 2010

Slipping 24 Inch (610 mm) Radii with the GT-3400



The GT-3400's operator stands inside the stringline with the remote control to watch the machine turn a radius on a parking lot project.

Garcia Concrete Construction Inc., based out of Fort Wayne, Indiana, specializes in municipality work, which includes new developments, parking lots, streets, subdivision work, and a variety of other specialized applications. The company, which consists of 14 employees including the owners, is a jack-of-all-trades, willing to take on any project. Adding to their versatility are two GOMACO curb and gutter machines, a GT-3600 and a GT-3400.

The GT-3400 is new to their fleet. It was a difficult decision for the company, whether to add another GT-3600 or try the different machine.

"We spent a lot of time comparing the two machines and what each of them was capable of doing," Manuel Garcia, one of the company owners, said. "In the end, I guess we just wanted to try something different, and we're glad that we did. Our GT-3400 is easy to set up, easy to operate, turns tight radii, and is very quiet to operate."

And, it's remote controlled, a feature that the operators enjoy. It allows them the freedom to move around the machine or to operate from the GT-3400's platform.

"The remote is definitely our favorite feature," Garcia said. "My guys can operate the machine from wherever they want to run it. They can always get into position for the best view, whether we're running a long section on a city street or turning a tight radius in a parking lot."

Garcia Concrete completed a parking lot project for a large retail store with their GT-3400. They slipformed approximately 24,000 feet (7315 m) of chair back-style curb and gutter. The profile featured a six inch (152 mm) tall curb with a 24 inch (610 mm) wide gutter. The parking lot also featured lots of radius work, some of them as tight as 24 inches (610 mm).

Project specifications also required two steel reinforcing cables be fed into the mold as the curb and gutter was slipformed. Because of the requirement, the entire project had to be pretrimmed with the GT-3400.

"The trimmerhead has so much power and was able to cut through the rock subgrade without any problems," Garcia said. "When the trimming was completed, we just sideshifted it out of the way so we had room to insert the steel reinforcing cables."

The GT-3400's trimmer is the most powerful on the market today. The direct-drive trimmerhead is driven with a radial piston hydraulic motor. It has 28,684 inch-pounds (3241 N-m) of torque at the trimmerhead to cut through the toughest of subgrades.




The mold is lifted and sideshifted out of the way during pretrimming.



Two steel cables are slipformed into the curb. The GT-3400's trimmerhead is raised and sideshifted out of the way to allow for the cable to be fed into the front of the mold.




The GT-3400 is uniquely designed to handle the tight radii, short runs and sharp angles designed into parking lots. Its compact size allows it to get into tight areas and its extra-large capacity hopper holds more concrete to complete tight radii.

It utilizes three steer sensors to turn tight radii. One sensor is located at the tip of the front track (Sensor 1); one is located at the front of the stainless (Sensor 2); and one is located at the back of the stainless (Sensor 3). Sensor 1 and 2 control the front tracks and Sensor 3 controls the rear track for both forward and reverse steer. As the GT-3400 enters the radius, the operator switches from Sensor 1 to Sensor 2 with a toggle switch on the remote. The combination of the hopper and the charging auger enables the GT-3400 to continuously travel through a tight radius without waiting for concrete delivery.

"Our radius work turns out great," Garcia said. "We just make sure that we've pre-trimmed the subgrade low enough, so we're not having problems with any stones getting underneath the mold. The concrete slump has to be just right, as well."

Garcia Concrete uses a standard 4000 psi (27.6 MPa) crushed limestone mix design. Slump averages two inches (51 mm). Curb and gutter production averages between 6000 to 7000 feet (1829 to 2134 m) per day.

"The two-speed motors allow us to move across our projects fast," Garcia said. "It's so quiet, too. I can stand on the machine and have a telephone conversation. It's a really great machine for what we do... it's small, like us... but we're still growing."




The GT-3400 was designed for the challenging conditions created in parking lots, which can include several tight radii and short runs of curb and gutter.



Curb and gutter production averages between 6000 to 7000 feet (1829 to 2134 m) per day on Garcia's parking lot projects in Indiana.






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