When Marra Services tackles complex, large-diameter sewer and manhole repair projects, it brings out the heavy artillery: a Quadex I-MARS Gen1 infrastructure rehabilitation system that has significantly amped up the Cleveland-based company’s productivity and profitability.

A good example is a project the company took on in 2018 in Lakewood, a western suburb of Cleveland located along Lake Erie. The project required repairing a 129-foot-deep brick manhole that ranged from 4 to 8 feet in diameter, plus an egg-shaped brick culvert that was roughly 350 feet long, 6 1/2 feet tall and 5 1/2 feet wide. The manhole and the culvert were built in 1912 and 1915 respectively and were deteriorating badly.

“It was one of the more difficult jobs we’ve ever done, particularly the manhole because it was more than 100 feet deep, which made spraying the mortar a real challenge,” says Nick Marra, company vice president. “We had to use a crane to lower a man-basket into the manhole. We also had to spray the mortar on thicker — up to 3 inches in some areas.”

While the project was difficult, it played to the strengths of the I-MARS rig (International Mobile Asset Renewal System), which can maintain pumping pressure over long distances and repair oddly shaped sewer lines.

Big investment

Founded in 2006, Marra Services works primarily for municipalities in Ohio and Michigan and employs about 30 people. The business first bought a remote-operated spincast Quadex sprayMASTER system about six years ago for lining small manholes. It cost around $65,000.

Later, the company invested approximately $500,000 in the I-MARS system; that price tag also included training and Quadex’s RMX-5000 mortar-mixing/pumping unit.

“You’re always taking a risk when you invest that much money in equipment,” Marra says. “But there’s a lot of sewer rehab work out there, so we decided to buy it. We were pretty confident it would pay for itself fairly quickly, and a lot of that confidence came from the people at Quadex. The customer service is excellent. Now we probably do a couple million dollars a year in spray liners for sewer lines.”

Portability and productivity

The I-MARS system’s relatively small footprint — roughly 13 feet long by 7 feet wide by 6 feet tall — provides a productivity and efficiency boost by combining a compressor, a generator, a 4-ton chiller and a power distribution center in one portable unit. It weighs 5,200 pounds.

“We used to have to bring along an air compressor, a water trailer and other equipment,” Marra says. “Now everything is all in one unit, which saves us a lot of setup time.”

The RMX-5000, which measures 11 1/2 feet long by 5 feet wide by 5 feet tall and weighs 5,500 pounds, features a 1,000-pound-capacity mixer, a 1,200-pound-capacity hopper, a 65 hp Yanmar diesel engine and a pump that generates 3,000 psi and is capable of spraying up to 5 cubic yards of material per hour.

“The technology for mixing and pumping the material is better than with other systems we’ve used,” Marra says.

On a good day, a crew can spray about 225 feet of sewer line per shift, compared to around 125 feet per shift with other equipment the company has used in the past. And they can spray about 50 to 60 feet per day on manholes, compared to 20 to 25 feet per day before.

“When we can roughly double our production, it helps us get more work because we can be more competitive with bidding,” Marra notes.

Tough geopolymer mortar

To line infrastructure, the company often uses Quadex GeoKrete, a formulated eco-friendly mortar. When mixed with water, GeoKrete forms an inorganic polymer with strong bonding properties.

Furthermore, GeoKrete is fully structural and corrosion-resistant; can be applied by trowel, spincasting or spraying; can be used in cooler winter temperatures (but heaters are required and the company uses units from Frost Fighter); and cures with virtually no shrinkage. Curing time is about 24 hours before recoating. GeoKrete lasts for about 50 years.

Marra says there is a learning curve involved in using the I-MARS system because there are many variables to consider when spray-lining sewers and manholes, all of which determine how well the lining material will adhere and cure. As such, it makes sense to have Quadex personnel on site for the first several jobs, Marra suggests.

“Quadex provides great field support,” he says. “They’re always available to help.”

Game-changing technology

The Lakewood project in 2018 took 23 days to complete over the course of a roughly two-month period due to late-spring snow and rain. It earned the company about $700,000, which paid for the cost of the I-MARS system. The I-MARS system’s relatively small equipment footprint allowed roads above the project to remain open.

“We couldn’t have done that job without the I-MARS system,” Marra says. “It’s been a very valuable piece of equipment for us. We’ve grown quite a bit since we bought it, not just because of the equipment, but the doors it opened up for us for jobs we couldn’t do before. Also, Quadex is a contractor, too, so we’ve been hired to work with them at times, which increases our business opportunities with companies we hadn’t worked with before.”

Marra notes that the company was rehabbing sewers and manholes for years before it bought the Quadex equipment.

“But because we can work so much more efficiently now, we go after a lot more jobs than we used to,” he says.