Preserving Arlington Memorial Bridge

WMC Contracting Slipform Paves Throughout Tennessee

Wed June 06, 2007 - Southeast Edition
CEG



WMC Contracting Company in Trenton, Tenn., has been in the construction business since 1950, and has specialized in slipform concrete projects of all kinds. If WMC thinks the project can be slipformed, it will figure out a way to do the job with GOMACO machines, using either one of its Commander IIIs or GT-3600.

Dennis Garcia, president of WMC Contracting, has just as much experience in the concrete industry as the company he’s currently operating. He’s worked as a laborer, equipment salesman and in management. He’s seen it all, worked with it all and sold it all.

WMC has two Commander IIIs that slipform all of its barrier or parapet projects. Curb and gutter work is completed with its GT-3600. The company completes projects all over the state of Tennessee and its equipment has to be easily transportable, a requirement that is easily achieved by both the Commander III and GT-3600.

One of its first projects with the new GT-3600 was slipforming 11,000 feet (3,353 m) of roll-over style curb and gutter in Medina, Tenn. Its work was part of the second phase of the Southern Hills Subdivision by Clark Family Homes.

“This is the third GT-3600 our company has owned and it’s the best one by far,” Garcia said. “We like the new design, and the G21 controller, which makes controlling it so smooth. Everything is smoother on this machine. We put our new machine together, took it out and went to work with it. We didn’t require a serviceman or any extra training for the new computer controls.”

WMC’s new machine is equipped with the Commander III style legs with “smart” cylinders. The machine has a two-speed track motor that makes moving it around the job site very fast. It also has the optional auger-style conveyor.

“We think the auger is better for the kind of work that we do,” Garcia explained. “When we’re in a tight situation going around a radius, we can load up the hopper, load up the auger, and then load up the hopper on the auger to make almost a complete radius before we have to stage a truck. I also like the way it just seems to move a lot of concrete.”

WMC also chose to go with the optional trimmerhead. It’s a direct-drive, radial piston motor that has more torque and more power for tough trimming conditions. It’s a feature that WMC is happy to have. On most projects, WMC trims through compacted gravel with a 95 percent compaction requirement.

“We’re always trimming and pouring at the same time on our projects,” Garcia explained. “We went with the new optional trimmer and it has made a huge difference. It’s just a very powerful trimmer that does an excellent job for us.”

WMC’s concrete mix design is a state-approved Class-A slipform concrete with a required 20 percent fly ash content. It likes to keep its sand to rock percentage at 58 percent rock and 42 percent sand for a durable product that finishes smoothly. Slump averages 1.5 in. (3.8 cm) for its curb and gutter projects.

Production is often times dependent on concrete delivery. It’s one of the few problems WMC Contracting has experienced with its new GT-3600 — it’s too fast.

“Our only limiting production factor now is how much concrete we can get to the machine,” Garcia said. “The suppliers that we work with all the time know and understand that we need ready-mix trucks 15 minutes apart and that timing works well for us. We run into trouble when we go someplace new. They just have trouble keeping up with us.”

WMC does some radius work on its projects and it usually averages around 5 ft. (1.5 m). A size that, according to Garcia, is no big deal.

“All we do is switch to our second set of sensors and go around the corner,” he said. “We don’t do anything special, just go around the radius and keep on going down the line.”

On a typical curb and gutter project, WMC likes to average 200 cu. yds. (153 cu m) of production per day. Finishing work is kept to a minimum with a light broom finish. It’s a state of Tennessee specification that all joints are saw cut into the curb and gutter the day following the pour. Joints are saw cut every 10 ft. (3 m).

Overall, Garcia and WMC are very happy with their GT-3600, but the slipforming equipment is just part of the reason why WMC keeps going back to GOMACO.

“The equipment is great and very user-friendly,” Garcia said. “Truthfully though, I like the people and I like their parts response. Their service is top notch and we enjoy being able to send our guys to their GOMACO University for training. Those are some of the biggest reasons why we choose GOMACO.”

For more information, visit www.gomaco.com.

(This article was printed with permission from GOMACO World.)