There are lots of ways to get concrete from the ready-mix truck to exactly where you want it when placing a slab on grade, but the bottom line is you want to keep the hand work to a minimum. How you select among the available options depends on access conditions, timing considerations, and economics.

“Pumping should be the first option,” says Keith Bauer of Charlotte, N.C.-based Carolina Coastal Pumping. And for many, it is. Pumping offers speed and also keeps the weight of ready-mix trucks away from the slab base. But there are good alternatives to consider when pumping isn't practical.

According to Todd Truemper, of Tilt-Con Corp., Orlando, Fla., choosing the delivery method depends on job access and what's being embedded in the pour. Having access in and around the site, with good subgrade that will support the delivery trucks, is a key criterion.

Beyond that, what's in the floor can make discharging directly from the truck's chute difficult. “If there are a lot of block-outs, a lot of plumbing, that means you'll have to be jockeying trucks all around,” Truemper says. Tilt-Con self-performs tilt-up panel work as well as foundations and slabs on grade. This type of work frequently is supported by company-owned concrete boom pumps.

Got good subgrade?

Jeff Hamburg, president of Blair Concrete Services, Wilmington, N.C., says successful concrete delivery hinges on site logistics and pumping methods.

“Subgrade is everything,” Hamburg says. “If access permits it and the subgrade can support the weight of the ready-mix trucks, truck dumping is optimum.” However, if either poses a problem, Hamburg's next preference is to pump. With the bulk of the company's work now consisting of hospital and university buildings, most are pumped with a system, often including several hundred feet of pipe. The challenge, he says, is to have a placing crew that knows how to move the hose around to place the concrete efficiently.

On projects where a boom pump is a feasible option, the company sometimes uses one placing crew and two pumps and piping systems in a leapfrog fashion. The concept is simple: The crew places as much concrete as it can within the reach of the first pump. They continue with concrete from the second pump while a smaller crew breaks down the first line and repositions the pump. By the time the placing crew reaches the limit of the second pump, the repositioned first pump is again ready to go. “We do end up spending a little more on pumping,” Hamburg says, “but we can pour twice as fast. Also, this way we always have a built-in backup pump available.”

Overhead clearance is another important part of site access. Brothers Joe and Scott Swederski of Swederski Concrete Construction, Spring Grove, Ill., like to pump concrete when they can. But much of their work is in large warehouses that already are under cover. Even when you can get a pump truck inside, “it takes a lot of headroom to open up a pump,” says Joe Swederski. “Plus, there can be a ventilation problem in enclosed spaces.” The crew typically is already running a laser screed, and adding the exhaust from a pump truck can require additional ventilation.

One alternative is to pump from the doorway, but that's when the weight of hoses filled with concrete comes into play. “It isn't long before your crew's tongues are hanging out,” he says. Using old finishing pans as “saucers” helps the hose slide over rebar. But they often find using buggies is a better option to shuttle the concrete from the truck to the point of placement. This is particularly helpful in smaller retail buildings without large overhead doors.

The company owns three buggies and can haul as much as a cubic yard per trip. “In some cases, they're much more efficient than dragging around concrete hoses,” says Scott Swederski. “And they also help keep the injury rate down.”