Up, Down and Around
|The golf cart path snakes up and down hills with 36 to 40 percent grade, around radii as tight as 15 feet (4.57 m), and through several dense patches of trees. "I wouldn't have tackled a job like this with anything but a GOMACO," Mark Landwehr, president of Landmark Concrete Inc., said. Landwehr's GOMACO of choice was the Commander III.
Slipforming the 28,000 feet (8534 m) of golf cart path began in the fall of 1998 at the new Spirit Hollow Golf Course in Burlington, Iowa. The terrain and the design of the course created some serious challenges.
"We poured eight foot (2.44 m) wide concrete cart path, four inches (102 mm) thick on very tough hills in the clay. The hills were up and down and some were up to a 36 to 40 percent grade," Landwehr said. "We were also going around corners that were as tight as a 15 foot (4.57 m) radius and in the trees."
The cart path also needed to be slipformed with cross slopes of 12, 14 and 16 percent. To accommodate the difficult cross slope, Landwehr rearranged his sensors.
"We ran a sensor right on the track and ran stringline control on one side of the machine. On the opposite side, where you normally run slope control, we ran a grade control," Landwehr said. "We mounted a sensor on the track and we had the machine follow the existing grade. That was actually a secret for us getting the job done."
A dozer was used to prepare the grade ahead of the machine. Landwehr then trimmed and poured simultaneously with the Commander III.
"We had the trimmer set for 10 feet (3.05 m) wide because we were over-trimming 12 inches (305 mm) on each side, but you have to when you're pouring tight radii," Landwehr said. "Part of this course was through a rock quarry with some pretty good chunks of limestone and that concerned me. The machine handled it great and I was really impressed."
The path was poured with four inches (102 mm) non-reinforced concrete with a 4000 psi (28 MPa) mix with .75 inch (19 mm) aggregate. Slump averaged around two inches (5 mm).
Joints were tooled in every 8 to 10 feet (2.44 to 3.05 m). Three men worked behind the Commander III bull floating the slab and applying a broom finish.
Production averaged around 300 yd3 (229 m3) per day. "That's not bad production," Landwehr said, "especially with the hills."
The hills created challenges for both the Commander III and the ready-mix trucks.
"Some of these hills were so steep we had to pull the ready-mix trucks up the hill in front of the machine with a dozer," he said. "When we went down, we'd flip on the track brake on the machine and that kept it from slipping and sliding down the hills. It was quite a challenge for us."
Landwehr had the load size the ready-mix trucks carried reduced when they slipformed the steep hills. "We kept the load size down to seven yards (5.4 m3) and it really helped," Landwehr said. "It made things safer for everybody and the concrete plant was so close that it wasn't a problem keeping mud in front of the machine."
Landmark also had difficulty maintaining decent haul roads. "The haul roads were miserable and it was tough getting the trucks up to the cart path in some places," Landwehr said. "There were a lot of areas where we actually had to back the trucks down the grade up to 2000 to 3000 feet (610 to 914 m).
"We had a plant only 15 minutes away from the job site and our supplier, Ideal Ready Mix, did a fantastic job for us," he said.
Spirit Hollow was designed by a landscape architect and features several radii through trees.
"There isn't a straight section of path on this whole golf course. The path just snakes all over the place," Landwehr said. "There were lots of trees, too. One nice feature on this machine is the telescoping leg. Sometimes just to get by the trees we'd have to suck that leg in as we were pouring and that worked great."
Sometimes the clearances got so tight that Landwehr had to pull the sensors and sensor arms off the machine to get past.
Landmark Concrete, Inc., based out of East Bethel, Minnesota, finished slipforming the path in the fall of 1999.
"I like GOMACO machines and I've been around them a long time. I was really impressed and happy with the way the Commander III operated," Landwehr said. "It had enough power to run the hills, trim, and also be able to pull a pretty tight radius. It's a great machine and I'm just tickled pink with it."