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Ottawa prof’s pothole-resistant paving technology finally put to use

One day in 1982, when Abd El Halim was still a graduate student at the University of Waterloo, he stopped to watch a paving crew at work near his house.

Fascinated, El Halim studied the steel cylinder of the asphalt roller as it met the hot, black road surface, leaving a network of fine fissures in its wake.

It struck El Halim then and there that the key to eradicating potholes was eliminating those cracks, which collect water that freezes and expands, heaving and breaking apart the road surface.

El Halim immediately went to work.

“I believe this is the beginning of the end of potholes,” he declared five years later in an interview with CBC News as he showed off his new invention.

But for El Halim, now a civil engineering professor at Carleton University, it’s been a long, bumpy road to recognition by the industry.

Abd El Halim

Abd El Halim demonstrates the concept behind his rubber-belted asphalt roller in 1987. (CBC)

AMIR is born

​Back in the 1980s, El Halim had realized that while most of the technology involved in building and repairing roads had advanced over the years, one key tool had not.

“When you read the history of asphalt, you realize that everything has changed,” El Halim told CBC. “But the roller did not change, and the rollers were not designed by a civil engineer, or any engineer.”

‘Money is going between the cracks’1:04

His solution was to replace the roller’s traditional cylindrical wheel with a rubber belt on a track, similar to a snowmobile.

The belt spread the weight of the compacting machine over a larger area, preventing the cracks in the freshly laid asphalt.

He called his machine the asphalt multi-integrated roller, or AMIR — also his son’s name.

“That shows you how much I loved the roller,” El Halim said.

Bumps in the road

Shortly after he unveiled AMIR, El Halim tested it with a Toronto-based tunnelling equipment company. Later, further research conducted with the help of about $500,000 in funding from the National Research Council (NRC) concluded the prototype was “overall quite successful” and “provided a crack-free surface.”

cracks

A key fob helps demonstrate the scale of the cracks left behind in test strip of fresh asphalt rolled by a traditional steel cylinder. (Supplied)

But the testing didn’t go perfectly.

On a slope, the belt had a tendency to come off. The early version of AMIR was also difficult to steer, and at one point the prototype wandered across the centre line of a test road on the NRC campus.

El Halim ran out of research money in 2003, a blow the inventor took personally.

“Like in any other field, you always have enemies of new ideas, people interested in not having you succeed in what you are doing,” he said.

Interviewed in 2008, having generated little to no commercial interest in his prototype, which was then nearly 20 years old and gathering rust, El Halim expressed frustration with an industry reluctant to adapt to new ways.

“Why should they change their technology when nobody is forcing them to?” he asked.

A chance meeting

Then in 2010, a chance meeting with a Ministry of Transportation (MTO) engineer and former student rekindled interest in the all-but-forgotten project.

“Nobody [had] linked permeability to the construction techniques in the field,” said Frank Pinder, MTO’s engineer responsible for pavement contracting in eastern Ontario.

AMIR-1

In 2008, El Halim showed off the AMIR prototype that had been developed by Carleton University and the National Research Council in the 1980s to CBC. (Simon Gardner/CBC)

MTO became seriously involved in testing a new prototype of AMIR in 2012. The results, observed over several highway tests, were promising.

As Pinder pointed out, it makes some sense that the commercial paving industry wasn’t interested in eliminating potholes — after all, the perennial need to fill them in ensures subsequent maintenance contracts.

A long time coming

“That’s why it’s taken such a long time to move it along,” Pinder said.

That’s also why it ultimately fell to the MTO to help develop AMIR as a way to save taxpayers money.

​Last year, the MTO looked at how much money pavement that lasted just one year longer than average would save the province, and came up with a figure of $50 million annually.

In fact, the Ministry of Transportation is now in the process of developing water permeability standards that will be specified in new road contracts in the future. That means companies will need to figure out how to lay down crack-free asphalt, and could lead to widespread commercial interest in AMIR after all.

Russ Perry

R.W. Tomlinson’s Russ Perry has been overseeing a $500,000 project to develop an AMIR-inspired prototype. (Stu Mills/CBC)

Tomlinson takes notice

Already, Ottawa construction firm R.W. Tomlinson has retrofitted a traditional asphalt roller by removing its twin steel drums and replacing them with AMIR-inspired belt rollers, which it developed with El Halim.

‘We’re hopeful that at some point in time, these machines are seen on the road every day.’– Russ Perry, R.W. Tomlinson

“Tomlinson sees the value in this,” said Russ Perry, the company’s vice president of heavy civil engineering.

Tomlinson has used the machine on a handful of projects, including resurfacing of a lane of Didsbury Road in November 2017.

There, belt-rolled pavement outperformed the cylinder-rolled surface in a head-to-head test of water permeability as decision makers from government and industry looked on. El Halim, who had by then earned the nickname “Professor of Pavement,” stood and watched, too, just as he had 36 years earlier.

Proving ground

Perry said Tomlinson is so convinced of AMIR’s superiority that it’s kitting out a second roller, which it plans to use on a 42-kilometre paving project in the Bancroft, Ont., area later this year.

Tomlinson has invested about $500,000 in the technology so far, and Perry estimates a single, more efficient AMIR roller can replace up to three traditional asphalt rollers.

“We’re hopeful that at some point in time, these machines are seen on the road every day,” Perry said.

For El Halim, who’s now preparing to retire from his job at Carleton, the promise of commercial success has been worth the wait.

“A true researcher always dreams of serving the public by offering good, economic, safe solutions,” he said. “If you are afraid of new ideas, due to ignorance, it is very difficult to succeed.”

AMIR

R.W. Tomlinson’s modified roller uses AMIR-type tracks rather than traditional steel cylinders. The company is currently converting a second machine, which it plans to use on a highway project near Bancroft, Ont. (Stu Mills/CBC)


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