By Cole Parkinson
With the Village of Barnwell experiencing some road issues, particularly on 6th Avenue, a new option for repairs has been brought forward to council.
During their regular meeting on June 20, a representative from Paradox Access Solutions was in council chambers to explain how their product could be of benefit for the village.
Paradox Access Solutions is a construction company specializing in customized access solutions for companies who need temporary or permanent roadways built on unstable terrain and they offer their own type of geocell.
“What this is, is called a geocell. This is our brand of geocell called ToughCell, it is the best one you can get on the market and what it does is it stretches into a big honeycomb. It can be stretched over a road and can be filled with material. The benefit of a geocell is its material confinement system for inferior building materials. These were invented in the 1970s by the U.S. Army core of engineers. The patents were released in the 1990s and the reason they were invented was because the U.S. Army needed a way to get big things like tanks and artillery on to beaches. Sand on its own is not a great building material unless you can confine it,” explained John Laycock. “If you put sand in a strong sand pail, you can get extremely high levels of compaction and probably park a truck on that sand. This is essentially millions of sand pails built underneath your road surface. It allows people all over the world, in military and non-military applications, to build in places with the material they usually could not build with because they couldn’t get good compaction.”
In terms of the usage in Barnwell, Haycock stated the geocell would curb the need for continuous repairs on roads.
“We lay the fabric down on the surface and then stretch the cells over the fabric. I’ve talked to Wendy a few times about your 6th Avenue road that is failing and you have been spending a lot of money on fixing it over and over, from 2nd Street to Heritage Boulevard. I’ve been speaking with your construction guys and you do use some geotechnical styles in your road building applications, most spec it right into the drawings,” he said. “We start with a non-loaded geo-tech style. These come in giant rolls, they are about two and a half metres wide by 10 metres or whatever project specific road we are dealing with. Lay this on top, stake it down on both sides and fill these cells with a number of different kinds of material. The big benefit to using a geocell in road construction is that instead of using your good gravel, which is really expensive and can be hard to find, what we can do it come in and reclaim the stuff that is already on that road surface. As long as it has less than 12 per cent fine material, we could fill the cells with essentially the garbage that was on top of the road before. Not only is it economical in that sense, but it is also a lot better way to build the road wasting aggregate you could be using or selling yourselves.”
One example the village council could relate to was work done by Paradox Access Solutions in the Village of Ryley, located in central Alberta.
Laycock explained they were experiencing similar issues to Barnwell with their roads before using Paradox.
“We were able to go there and their roads were very similar. They had a huge problem with their road, it was falling apart. One thing people need to understand is roads fail from the bottom up, not top down. If you are getting these big alligator cracks and your road is sinking, it is not because of what is happening on top but what is happening in your sub-structure. The enemy of all roads is water and we have very high water tables here.”
On top of less maintenance needed, the actual work to install the geocell would take less time than a normal road repair.
“What this does, instead of going in and digging out an entire road like you would in a conventional road build, you dig down a very small amount. Sometimes it is only 30 centimetres and you put this over top. Think of it as a big snowshoe, when loads go across it creates a beam effect. When those vibrations from tires going over top, instead of going straight down they are dispersed horizontally. All of that pressure going to the failing subgrade doesn’t get there, it gets dispersed,” said Laycock. “What we are looking at doing here is instead of trying to do the same thing, let’s do this right. We don’t build a whole bunch of brand new roads in Alberta but we fix a ton of old roads. We keep doing it the same way expecting different results.”
Council inquired about the cost for Paradox to come in and do their work in the village.
“We have done a pretty big cost-benefit analysis on what it would take to rebuild that road conventionally to give you the life you are looking to get out of it, comparatively to using what is there and the cells instead. It costs about the same to redo it in the initial rebuild but over the life of that project, over that 10 years it is about three times higher if you do it conventionally because you do a lot less maintenance, you don’t get sinking asphalt and you can use a lot less asphalt,” said Laycock. “If you look at the expense put into doing it versus conventionally, it is not more expensive. Matter of fact it is a bit cheaper up front because of less material.”
In a rough estimate, Laycock stated it would be a maximum of $178,000 using Paradox and $199,000 going with a conventional repair route.
“On 6th Avenue, we thought we may be able to not touch the base and overlay on the existing asphalt,” said Coun. Kent Bullock. “I understand where you are coming from but I think it is way overkill for our situation.”
“You could just put a fresh overlay on it now but because your subgrade is failing, you are going to end up doing it again,” replied Laycock.
Other councillors were in favour of trying the geocell if the quotes were actually going to come in cheaper than a traditional road repair.
“If it is going to be every bit as much or cheaper, I would like to try it,” said Coun. Robin Hansen, which was echoed by many of the councillors.