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New, improved and environmentally-friendly - Recycled asphalt |
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You would be hard pressed to find South Durham’s St. Louis Industries in the phone book, nor would you easily find the company’s head office on Rue de l’Eglise in South Durham. But there is a good chance, if you’re environmentally conscious, or if you worry about your tax dollars, or if you like driving on smooth pavement, you might soon be saying thank you to this small manufacturer of asphalt recycling equipment.
“We brought a four-ton bin recycler to Sherbrooke on May 2 for a demonstration,” said Eric St. Louis, who started his company in 2005. “The city representatives were impressed. There can be a three- or even 12-month gap between the time a municipality decides to order a machine and the time the order is actually placed, but I’m optimistic.”
City officials witnessed the recycling of asphalt. Large chunks of old asphalt destined for a toxic waste dump were put into what looks like little more than a large metal box mounted on wheels. What came out of the box was high-grade, fresh asphalt ready to patch potholes or re-pave roadways.
“The bin recycler, which comes in four-, six- or 10-ton models, is one of our three road-resurfacing products,” St. Louis said.
“We also manufacture an in-place recycler, which can handle a much larger volume of old asphalt, and a cold-joint heater. The machines are a little like giant toasters. They use controlled infra-red heat to soften up the old asphalt so as to make it re-usable.”
“The technology isn’t new. It was developed by Anton Heller in 1965. I had the good fortune to work with him in the 1980s and I now hold the patents. The machines I build today are more efficient and more refined, but the concept is tried and true,” added the Ontario-born entrepreneur.
The history of asphalt roadways goes back to a Scottish engineer, John McAdam (1756-1836), who made two significant contributions to road construction. In his native Scotland, he designed roadways with a slightly convex profile so that water would run off to the sides and therefore avoid eroding the road surface. Just as important, he conceived the idea of mixing coal tar with sand and small stones to create a smooth and relatively permanent road surface. MacAdam’s name is found both in the English word “tarmac” and even more obviously in the French word “macadam.”
“Roads today,” St. Louis said, “will typically consist of a base layer of two feet or more of crushed stone, on top of which is laid a six to eight inch layer of fine crushed stone, capped off by as much as four inches of asphalt. The asphalt consists of a base coat which is two to two and a half inches thick and a finer finishing coat which is an inch and a half to two inches thick.”
He pointed out that asphalt itself is a mixture of small stones (for strength), sand (for filler) and the oil-based tar known as asphalt cement. Today, there is no such thing as a left-over oil product; the tar used in asphalt is a by-product of the refining process that turns crude oil into gasoline.
While Eric St. Louis started his company barely three years ago, he is by no means new to road building. In fact, some might suggest it’s in his genes, as he proudly displayed a large, framed photo dating back to the 1930s.
“The man in the middle is my great-grandfather, Joseph St. Louis. As you can see by the excavation, his crew is laying down a sewer system. This was in Tecumseh, a small town near Windsor, Ontario, where the francophone St. Louis family settled in the 1600s. Joseph was, among many other things, in charge of roads. My father, Russ, brought his family to Quebec in the 1950s, when the company he worked for needed a francophone to oversee a new branch plant. In 1981 my dad started his own company which sold a wide variety of road maintenance equipment — pavers, graders, trucks, cranes, sweepers. At various times, two of my brothers and I worked for him.”
Russ St. Louis didn’t retire until he was in his 80s. Eric’s two brothers, Jonny and Kai, are now the owners of JKL, Quebec’s biggest seller of street sweepers.
“Our climate is hard on road surfaces,” added St. Louis, “because of our winters. Water seeps into the finest fissures and turns them into cracks. Water trickles into the roadbed, erodes it and causes potholes. But even in sunny California asphalt deteriorates. The sun burns off some of the oils in the asphalt and it loses flexibility. Oxidation causes it to go from black to grey. Especially in hot weather, heavy traffic wears down the asphalt surface.”
“The joke,” St. Louis said, with a smile, “is that McAdam paved the first road in 1820 and went back and fixed the potholes in 1821.”
According to the asphalt expert, our roads, unfortunately, have built-in flaws. Asphalt is laid down at around 320 F. The paver lays down a 12-foot swath in one direction, then comes back and lays down the other lane. But, regardless how perfect the seam when it’s fresh, the newly laid hot asphalt on the second lane never joins perfect with the cooler asphalt on the first lane. This is why you’ll often see long straight cracks down the middle of the road.
“What our cold-joint heater does is warm up the edge of the cold asphalt so that, at the joint, hot asphalt can meld with hot asphalt and greatly reduce the risk of cracking,” he said.
What the cold joint heater does for cracks in asphalt, the bin recyclers do for potholes and larger patches of damaged asphalt.
“At one demonstration we scattered a bit of cement powder onto the recycled asphalt to make it look old and oxidized. The public works foreman had to look long and hard to find the patch we’d just laid down,” said St. Louis.
“But the real beauty of the process is that it’s environmentally friendly, and economically attractive,” he continues. “As things are right now, every municipality in the province and the Quebec Ministry of Transport as well, find themselves with growing piles of old asphalt which has been ripped up and which has to be disposed of in toxic dumps at a cost of a few dollars a ton.”
When a road is re-surfaced a cold-planer — in essence a large drum with
carbide teeth — scrapes the top one or two inches off the road surface leaving a scarred layer over which fresh asphalt will be laid.
“What our machines can do is recuperate all of that waste asphalt and re-use it time and time again.”
Patching pot holes is particularly problematic for municipalities in the winter and spring.
“In the summer you’ll find portable asphalt plants parked all over the province. In the winter, except for Montreal and Quebec City, there is nowhere to get fresh asphalt. An official from a mid-sized city recently described to me what his city has to do to patch roads in the winter. They send a 20-ton truck on a 340 km round-trip jaunt, about four and a half hours, to get a hot mix of asphalt for which they pay $100/ton for a total cost of about $2500. That works out to about $125/ton. Our 4-ton bin recycler costs $60,000, but it can provide fresh, recycled asphalt virtually anywhere, anytime for about $7/ton.”
Despite the fact that his company has, to date, only made three sales (one of them to a road contractor in Santiago, Chili) Eric St. Louis all but bubbles with humour and enthusiasm.
“In Quebec, a small or medium-sized business is called a PME, but that doesn’t stand for Petite et Moyenne Entreprise,” he laughs. “It stands for Petit Manufacturier Endetté [in debt], or if you prefer, it can also stand for Pas les Moyens Economiques.”
“Sure, I could use about a million bucks right now, but I’m lucky. I’ve got my brother, Alex, and a few friends volunteering their time, because, like me, they believe in this. And, I’ve got a product line that can only grow more attractive as oil costs rise and as people grow more environmentally conscious.”
The company is at
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By Nick Fonda
May 31, 2008 |
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Montreal Canadiens
