Centripipe

Culvert Repair: Slip-Lining Versus Relining With Centrifugally Cast Centripipe

In February, 2013, the Saskatchewan Ministry of Highways started a culvert repair project on Highway 9 to test three competing methods of culvert rehabilitation. The methods that Saskatchewan wanted to compare were:

1.replacing old culvert by boring new parallel culvert
2.repairing culvert by slip-lining a new liner into the old pipe
3.relining old culvert with centrifugally cast concrete CentriPipe

One of the main advantages of relining with CentriPipe is that the culvert’s capacity is preserved – the concrete liner does not significantly reduce the culvert’s diameter or capacity.

CULVERT REHABILITATION PHOTOS:

I visited the Highway 9 culvert site in Saskastchewan last week to see how the sliplining solution compared to the CentriPipe culvert we did in February. Here are some dramatic photos showing the difference between sliplining and CentriPipe:

 48" CMP culvert relined with centrifugally cast CentriPipe concrete liner. No significant reduction in flow capacity.

48" CMP culvert relined with centrifugally cast CentriPipe concrete liner. No significant reduction in flow capacity.

 About half a kilometer up the road, this 48" culvert was rehabilitated with a slip-lining solution.

About half a kilometer up the road, this 48" culvert was rehabilitated with a slip-lining solution.

 This culvert's ID was reduced from 48" to 30". The CentriPipe culvert's new ID is 46".

This culvert's ID was reduced from 48" to 30". The CentriPipe culvert's new ID is 46".

Compared to the CentriPipe centrifugally cast concrete culvert, the slip-lined culvert is 35% smaller (30″ compared to 46″). This translates in a 58% difference in flow capacity between the two relined culverts (3.6 m3/s with CentriPipe down to 1.5 m3/s with slip-lining).  If keeping a culvert’s high flow capacity is important to you, please consider CentriPipe centrifugally cast relining.

Martech represents APM CentriPipe in Canada. If you have deteriorating culverts in your area, ask us for help in getting your culverts repaired with CentriPipe.

Kansas Stormwater Pipes Rehabilitated With Centrifugally Cast Concrete Pipe

50 YEAR OLD STORM PIPES REPAIRED with APM CENTRIPIPE

About 18 months ago, Nicholas A. Willis was starting his new job as Stormwater and Conservation Superintendent in Hays, Kansas. Willis decided to take a closer look at the stormwater sewers underneath the picturesque brick streets in the city’s center.

The 48″ arched corrugated metal pipe (CMP) sewer was just over 50 years old, according to city records. 50 years is near the maximum lifespan for CMP, so Willis wasn’t expecting to find the pipe in perfect condition — still, what he did find surprised him.

“Basically, it was a cave,” Willis says. “Pipe had rusted out and been washed downstream, so I was shining my flashlight at an earth void and could see the under layer of the brick street. That’s just 6 inches of mesh-reinforced concrete, and we get semi trucks and school buses in that part of town. I’m amazed it held up.”

URGENT REPAIRS to AVOID DAMAGE AND INJURY

After closing the street and initiating emergency repairs, the department inspected all of the large-diameter CMP storm pipes and culverts in the Hays’ system. “Given that this pipe was installed in the early 1950s, it’s performed pretty well,” Willis says. “We have high pH soil, so pipe wasn’t being eaten from the outside. But 50-plus years is a long time.”

The system-wide inspection revealed about 300 feet of collapsing sewer that was immediately addressed by trenching and replacement. And with that work done, there was still several thousand feet of pipe with rotted-out inverts or other significant damage. Some of it ran underneath brick streets for hundreds of feet and replacement by trenching would have been expensive — about $490/foot — and would have seriously disrupted downtown traffic.

Willis decided to evaluate several trenchless methods. “We looked at just about everything, including two types of CIPP [cured-in-place pipe],” he says. “CentriPipe was the best on price by far. For large-diameter pipe, nothing else was even close.”

APM CENTRIPIPE SELECTED TO REHABILITATE KANSAS STORMWATER PIPES

CentriPipe is a proven centrifugally cast concrete pipe (CCCP) rehabilitation method developed by AP/M Permaform. A spincaster is inserted at one end of the pipe and pulled through at a calculated speed to apply thin layers of structural grout or epoxy mortar.

The finished product is smooth, tightly bonded, waterproof, and it doesn’t significantly reduce the pipe’s inner diameter or flow capacity. It’s especially efficient and cost-effective on large diameter pipe. The Florida Department of Transportation, for example, has used CentriPipe to rehabilitate sewers up to 13 feet in diameter.

Crucially for Hays, CentriPipe is completely structural and adheres tightly to most substrates, including CMP. It’s as if a new concrete pipe is built into the sewer. The condition of the old, deteriorated pipe doesn’t affect the performance of the new CentriPipe concrete liner.

TRIAL PROJECT to TEST APM CENTRIPIPE

In 2011, Willis decided to test CentriPipe by rehabilitating 968 feet of 30 and 48 inch sewer pipe before selecting it as the prime solution for all of Hays’ failing sewers.

“We wanted to see how it performed and how it cured out over winter,” Willis explains. “It did fine — there were some hairline cracks, like you would see in any concrete work, but after a year, it is all holding up very well with no shedding.”

In 2012, Hays rehabilitated an additional 2,500 ft of pipe. Willis anticipates about 2,000 feet each year for a few more years. Costs work out to $180/lf with almost no traffic disruption. “With the amount of work that has to be done, I don’t know how else we’d be able to catch up,” Willis says. “For efficiency and cost, this has been a great solution for us.”

Since the CMP in Hays is arched and concrete is applied by a spincaster, Willis says the new concrete was thicker ‘at ten and two’ but that this doesn’t really affect performance. Most pipes required two or three passes, one to fill in and smooth out pipe corrugations, and one or two additional layers to add strength. One-inch layer thicknesses were specified, and inspection was done with a fairly low-tech method.

“We just drilled into it in a few places until we got to metal,” Willis explains. “We found that coverage was even and predictable and we didn’t need to drill into too many places.”

CITY OF HAYS, KANSAS HAPPY WITH APM CENTRIPIPE RESULTS

Finding out that you’ve inherited a sewer system with failing pipe — and some pipe that has actually crumbled and washed away — isn’t the most pleasant way to start a new job. But Willis adapted quickly and has already addressed the most critical pipe in the system.

“We’re in a lot better shape after just two years, and CentriPipe is a big part of that,” he says. “Given our time frame and revenue, I don’t see how we could do without something like this. To any city or agency on the fence about it, I certainly recommend giving CentriPipe a try.”

APM CentriPipe in Canada

APM CentriPipe and APM Permaform culvert and manhole rehabilitation products are represented in Canada by Martech. Please ask Martech to help make your culvert rehab project a success.

Culvert Relining With APM Centri-Pipe- Best For Deep Culvert Pipes

Trenchless culvert relining: alternative to digging, replacing or sliplining old culvert pipes

I have discovered that most of Saskatchewan’s rural municipalities have at least one culvert that’s too expensive to dig up and replace. These culvert pipes are:

  • Too deep under the road,
  • Hard to access,
  • Too big,
  • Too long or
  • Under a road where the traffic is too high to dig up the roadway and replace the line.

Look at this culvert: 30 feet of soil above the pipe. Digging this up and replacing it would take weeks and tens of thousands of dollars.

 Photo: deteriorating culvert in Saskatchewan where the municipality can use Centri-Pipe to reline the pipe instead of digging up the road and replacing the culvert. In this location, there is 30 vertical feet of soil above the culvert pipe and it is not feasible to dig and replace. APM Centri-Pipe is the best option to save this culvert.

Photo: deteriorating culvert in Saskatchewan where the municipality can use Centri-Pipe to reline the pipe instead of digging up the road and replacing the culvert. In this location, there is 30 vertical feet of soil above the culvert pipe and it is not feasible to dig and replace. APM Centri-Pipe is the best option to save this culvert.

CENTRI-PIPE: PROVEN PIPE RELINING – trenchless alternative to culvert replacement and pipe sliplining

Culverts that were constructed during the 1980s are deteriorating and most are scheduled for replacement. Martech and AP/M Centri-Pipe want to introduce you to a proven culvert relining process that will save money and time for your department.

Centri-Pipe pipe relining has major benefits for small municipalities:

  • Centri-Pipe is a trenchless solution – DO NOT dig up your roadway
  • Reline your culvert pipe in a fast 1 to 3 day process
  • The new lining gives full structural support
  • Adds at least 40 years to your culvert’s service life (engineer says 70-100 years)
  • Works with culverts 30″ to 120″ pipe diameter
  • Almost zero loss of water flow rate after relining
  • Environmentally friendly, no toxins in the mix
  • Reline culverts all year round without stopping for winter
 Photo: APM Centri-Pipe culvert relining before and after comparison photo. Before relining with Centri-Pipe, the culvert's bottom (invert) had almost entirely corroded away and a large amount of soil had been removed by erosion.   

Photo: APM Centri-Pipe culvert relining before and after comparison photo. Before relining with Centri-Pipe, the culvert's bottom (invert) had almost entirely corroded away and a large amount of soil had been removed by erosion.