The hose for the air-pumped material is much easier to control than a concrete pump hose.
Air Pump USA The hose for the air-pumped material is much easier to control than a concrete pump hose.

Concrete pumps today are the primary way to place concrete. But what if the material you need to place is dry sand or gravel? Contractors have struggled for years to move sand, soils, and aggregate into inaccessible locations where earth-moving equipment won’t fit or other constraints won’t allow for it. Increases in labor costs and risk of bodily injury have made the old wheelbarrow or bucket method of moving materials a thing of the past.

The Air Pump was developed in 1996 to tackle these challenges. This equipment uses compressed air to deliver a variety of materials—sand, stone, crushed rock, decomposed granite, rock dust, and landscape soils—to distances upwards of 600 feet away. In addition to its original design application of backfilling concrete foundation walls, the system is used to fill abandoned wells, pipes, and culverts; planter boxes on elevated structures with both drainage rock and landscape soils; annular spaces for drilling and boring contractors; beach replenishment projects; and nondestructive placement of topping materials on turf systems.

A skid steer is used to load the pump hopper.
Air Pump USA A skid steer is used to load the pump hopper.

“The operation is very similar to a concrete pump; however, the technology of moving dry materials is very different,” says Michael Nolen, president of Air Pump USA, in Gardena, Calif., which manufactures the unique equipment and also operates as a subcontractor. “We work as an ally to the local concrete pumping contractors, solving customers’ access challenges with the most efficient piece of equipment.”

How It Works
The patented, self-contained system includes a two-axle flatbed truck with compressor, hydraulically operated pump, and hose reel. Mobilization is simple, and because there are no outriggers or other external requirements, the unit can operate in a single lane without disrupting adjacent traffic.

The material to be moved is typically dumped at a jobsite in bulk. It is then loaded into the Air Pump hopper with a skid steer where it runs through the pump and is discharged from the end of a lightweight, non-marking hose at the point of placement. When customers are using the pump, there’s an operator at the pump and a laborer at the end of the hose. Each has a radio so they are in constant communication, can stop or start the pump, or vary the amount of material discharging. “We’ve also had sensitive areas where customers don’t want bulk material on the ground,” Nolen says. “In this case, we order the dry material to be delivered directly to our air-pump hopper by way of drum mixers or slinger trucks.”

Each Air Pump truck is equipped with two hydraulically powered pumps that allow for simultaneous placement at two locations, increasing productivity and allowing crews to complete their work in a shorter time. “When pumping material, the hose weighs about 2 pounds per foot, which is much lighter and easier to maneuver than a hose completely full of concrete. At the end of an installation, or at a break, we are able to stop adding material and keep the pump going until the hose is totally blown out and clear,” Nolen explains.

In some sensitive applications, workers will use a diffuser on the end of the hose coupled with a water stream to act as a dust suppressant. “The benefits of adding proper moisture content at the discharge end is twofold. It aids in suppressing dust and can also help achieve proper compaction when needed,” Nolen says.

When the job is complete, the 50-foot hose sections are either taken apart and brought back to the truck or the hydraulically driven reel assists in bringing the hose back on board.

Dry material can be pumped up to 10 stories vertically and 300 feet horizontally.
Air Pump USA Dry material can be pumped up to 10 stories vertically and 300 feet horizontally.

The newest units are capable of pumping sands and aggregates up to 35 tons per hour and soils up to 40 cubic yards per hour over distances of 600 feet, depending on specific site conditions such as material type, distance, and elevation change. On a recent podium apartment project in Los Angeles, Air Pump USA successfully pumped 10 stories vertically and 300 feet horizontally. The customer had originally budgeted the placement using cranes, buckets, and wheelbarrows. Thinking outside the box and using the Air Pump equipment saved the contractor over $100,000 in labor costs and months of valuable job schedule time.

The Air Pump unit can be parked well away from where the material is needed, making the whole process very discreet. On construction sites, other trades can continue working while the backfilling operation is in progress. And the process is worker-friendly since the line pressure is only about 150 psi (compared to much higher pressures in a concrete pump). Unlike water hoses or concrete hoses, the air-pumped sand, gravel, and soil system has very little back pressure, which means workers never have to wrestle to keep the hoses under control. “It can pull back if you pinch it at a corner, but nothing like a shotcrete or concrete hose,” Nolen says. The lightweight hose and the even flow of material allows a smaller crew to place and grade more material than with other methods.

Once the hoses are set up and pumping has started, the material deliveries to the hopper area can be scheduled at constant intervals allowing for minimal traffic and jobsite disruptions.

A slab subbase can be placed easily indoors with the Air Pump.
Air Pump USA A slab subbase can be placed easily indoors with the Air Pump.

New locations and numerous uses for the Air Pump equipment are called for each week. Many of the large national landscaping firms such as Brightview, Park West, and Landscape Development Inc. are depending on the equipment regularly to service their difficult projects quickly, safely, and productively. Concrete contractors Webcor, McCarthy, and Largo have used the equipment to place wall backfill and subgrade sands beneath slabs on grade. Boring contractors have used the equipment for annular spaces, filling the void between conduit and lines; interlocking paving installers for setting bed sand; and plumbing contractors for trench backfills.

Air Pump USA has recently been used to replenish the beachfront at coastal properties in California from San Diego up to Santa Barbara. “We are constantly having new applications arise,” says Nolen. Many city building specifications are requiring new mechanical and electric line conduit to be encased with “air-blown sand” under roadways. Many of the new uses are by landscape contractors who are completing the mandated green spaces and green roofs on podium office and apartment buildings that are infilling our urban cities.

“It never gets old hearing customers thank us for how easy, efficient, and safe the system worked in completing their task,” Nolen says. “ ‘I wish I would have known about this equipment years ago,’ is another line I often hear.”

In sensitive areas, dry material can be loaded into the Air Pump from a mixer truck.
Air Pump USA In sensitive areas, dry material can be loaded into the Air Pump from a mixer truck.

Manufacturer or Service Provider?
Air Pump USA continues to test the boundaries of its equipment and update its patents. It has begun to expand its geographical reach through new partners and improvements to its designs. They currently operate five units in Southern California and recently partnered with material placement businesses in Michigan and Colorado.

“We design and operate our own trucks,” Nolen says. “We’ve manufactured and sold trucks to a select few outside operators who fit our criteria and provide top-notch service in their respective markets. We will continue operating as a hybrid, growing our service business, developing new, more-efficient prototypes, and selectively selling to customers that we think can be successful with the equipment. The challenges that customers continue to bring us keep us pushing the envelope in design and possibilities. We have assembled a great team and are really excited about the future of Air Pump USA.”