Gill Civil Engineering in Kent, England, has carved out a unique niche for itself in the last three years. The country has several prime contractors and most are not equipped to handle the slipform concrete work on contracts. Gill Civil Engineering saw that need and offer their subcontractor services solely as slipform pavers specializing in mainline paving for highways, runway and taxiway work at airports.
The company is constantly on the move, handling a variety of different projects and specifications. They needed a concrete paver that was easy to transport and could change widths quickly and easily. “I’ve been slipforming for 15 years all together now and I’ve always worked with GOMACO,” Simon Renker, paving contract manager for Gill Civil Engineering, said. “We chose the GHP-2800 because it’s so versatile and user-friendly. Everything is made simple to change from transport mode to paving mode and back again. It’s all made so simple, even changing the width of the frame is easy, and that’s really one of the best selling points on the machine.”
They recently finished up a taxiway and runway project at the Leeds and Bradford Airport in Leeds, England. The airport called for 16,744 sq yd of concrete and, according to Renker, was one of the company’s smallest projects.
“Basically, it was a taxiway that blended into a runway and it was a small job for us,” Renker said. “We bid it because of our versatile GHP-2800 and our ability to change widths with it very quickly and move it from site to site.”
Challenges have depth
The new taxiway/runway was built over the existing one that had been planed down. When the old structure was planed, though, it was planed at variable depths. Gill’s paving runs had to accommodate the inconsistency over the 79-ft-wide concrete paving.
“The variable depth was the tricky part,” Renker explained. “It was the reason the airport authorities wouldn’t let us go very wide with our paver.”
Paving was accomplished in five 15.75-ft-wide passes. Slab depth varied between 12.2 and 18.1 in. thick. Each pass was approximately 1,722 ft long.
Concrete on the project was supplied by Gill’s own batch plant. The company currently owns two plants purchased from GOMACO International Ltd.
“Obviously, if you understand slipform paving, you want to get your concrete just right, and having control of your batch plant allows you that,” Renker said. “We really are self-sufficient with our own batchers on site, our own transport and then we slipform it, as well.”
The batch plant has the capacity to produce an average of 157 cu yd per hour. On this project, production averaged 1,236 cu yd per day.
The Pavement Quality Concrete is a C-40 mix design with 641 lb per cu yd of cement. Slump averages 1.5 in.
Three articulated dump trucks capable of carrying 11.8-cu-yd loads delivered concrete to the site. An excavator was used to level out the concrete in front of the GHP-2800 paver.
“Our paver is a nice machine,” Renker said. “The lower engine and shroud gives a better view around it and it definitely is a lot quieter now. The G21 controller combined with the steering makes the paver more responsive.”
Behind the paver, the new slab has a bull-float finish followed by a brush-texture finish. Joints are wet saw cut 18 hours after the mainline paving during the winter months. Summer temperatures shorten that time down to six hours.
Joints are cut every 16.4 ft and crews cut up to 105 joints per day in the new runway/taxiway.
In addition to their paver, Gill Civil Engineering also owns a GOMACO four-track GT-6300. They certainly have the work for it with projects on several airports in England including the Birmingham Airport, the East Midlands Airport and the Manchester Airport.
