GOMACO World Index --- GOMACO World 35.1 - February 2007
The working conditions for curb and gutter contractors in southwestern British Columbia are extreme, to say the least. The majority of the work is renovation on dilapidated roads. Subdivision work is also common, with two or more curb profiles on the project. Mountains and steep grades in the area also add an element of difficulty to a curb and gutter project.
It’s because of these challenges and more that Winvan Paving Ltd., based out of New Westminster, British Columbia, Canada, has chosen to slipform curb and gutter with a GOMACO Commander III since 1976. They witnessed first-hand the evolution of the Commander III line, its various control systems and newest features.
“The sideshifting trimmerhead and mold has been a great advancement,” Joe Alves, concrete supervisor and 32-year employee of Winvan Paving, explained. “Right now we can start right up at an existing piece of curb and go right up and tie into another existing piece of curb with very little handwork to do because we can sideshift that trimmerhead out of the way.
“Plus, our first Commander III was all toggle switches and we like all of the new computer technology now with the G21 controller. It’s been pretty simple for our operator to learn the new system.”
Winvan tackles all types and sizes of curb and gutter projects, from smaller 656 feet (200 m) rehab projects on city streets to subdivisions with thousands of feet of curb and gutter. They like to complete two to three of the smaller projects in a single day, so transportability of a machine is a major consideration. Their Commander III drives right up onto a low-boy trailer and is ready to head to the next project.
City street rehabilitation projects can include all kinds of challenging conditions. In British Columbia, often times only half of the road is torn out at a time, keeping one lane open for traffic. Other times, the new road is already in place and the curb and gutter has to be poured in a trench next to the road. The Commander III can accommodate the changing conditions each project brings. The legs can be positioned in several different configurations with All-Track Positioning (ATP).
“On a lot of our renovating projects we’re right up tight to existing asphalt and that’s why the Commander III is so versatile,” Alves said. “We can position our legs and the mold any place that we want and we’re able to manage the project. It works out pretty good.”
Trimming and pouring simultaneously is another feature Winvan enjoys. The company does their own grade preparation and likes to leave the grade about two inches (51 mm) high.
“Sometimes that doesn’t happen and our grade ends up being from four to five inches (102 to 127 mm) too high,” Alves said. “It’s not a problem for our GOMACO because the trimmerhead has plenty of power.”
The company has 12 different curb and gutter profiles that they use on projects within their working area. Most of their subdivisions require two different profiles and on-site mold changes. It’s a process that doesn’t slow down production, or even concrete delivery.
“We get into a lot of projects where it requires different kinds of molds and we have to change over,” Alves explained. “It takes no time at all and we don’t even stop the concrete from coming. We just let them sit there for a little bit as we change the mold and then away we go again with a different profile of curb.”
New Westminster and the 50 mile (80 km) radius around the city that Winvan works in is very mountainous with a lot of steep grades. The Commander III has more than enough power to slipform the grades.
“We have a lot of mountains around here so it’s always up and down,” Alves explained. “Usually, when we’re pouring downhill, the only problem we have is sometimes trying to get the concrete out of the truck. But as far as paving uphill or downhill, we don’t have any problems at all with our GOMACO.”
Winvan’s stringline crew typically sets their stringline at a 39 inch (1000 mm) offset from the gutter line, but they will set it as close as 18 inches (450 mm). Their mix design is a standard slipformable concrete mix with .5 inch (13 mm) sized rock instead of the usual .75 inch (19 mm) rock. The size difference, according to Alves, helps with the final finish and a smoother curb. Slump averages one inch (25 mm) on their high-back curb and 1.5 inch (38 mm) for roll-over curb.
Production rates vary depending on the project. On subdivisions, they like to average around 3280 feet (1000 m) per day. Jobs with lots of traffic, tight clearances and extra challenges, Winvan is happy with 1312 feet (400 m) in a day.
“The finish on our curb and gutter has to be very good in Canada and our Commander III works well for us,” Alves said. “Every 10 feet (3 m) we have to cut in contraction joints and every 30 feet (9.1 m) there are expansion joints. It keeps our finishers busy.”
A time-saving and work-saving measure for Winvan’s finishers is the drive-way cutout on some of their curb and gutter molds.
“We have the driveway cutters on our high-back molds and they cut out all of the concrete, which means a lot less work for our guys working behind the machine,” Alves said. “All they have to do is throw in a board behind it, finish the driveway, and in less than 10 minutes, the driveway is done. We’re saving a lot on concrete and time.”
It’s time well-saved, so Winvan can bring in their low-boy trailer, load up their Commander III and head to their next project.