Alan Carter is a professor in the Department of Construction Engineering at the École de technologie supérieure (ÉTS). He applies his extensive knowledge to developing asphalt pavement that is less harmful to the environment.

“Hot asphalt smells good to me!” The co-director of ÉTS’s Pavements and Bituminous Materials Laboratory (LCMB) is clearly in his element as a researcher. Alan Carter jokingly admits that he is not the only one to appreciate the smell of freshly spread asphalt on roadways. But let us not get ahead of ourselves. To understand the passion that this professor in the Department of Construction Engineering at the École de Technologie Supérieure (ÉTS) has for his job, one needs to go back to his childhood in the Lower St. Lawrence.

In the late 1990s, young Carter was enthusiastically helping his father build garages and cabins in the woods. Surrounded by family friends who owned a hardware store, he heard them discuss the merits of wood paneling and various DIY tools. It was not surprising, therefore, that given these circumstances, this star student would opt to study architectural technology at Collège d'enseignement general et professionnel (CEGEP). Upon graduation, his interest in solving practical problems led him to enrol in the ÉTS’s construction engineering program.

At the ÉTS, he soon discovered research through his involvement in one of the student clubs. The goal was to build a concrete canoe that was as light as possible. “As team captain, I was responsible for producing a concrete mix by introducing additives, such as latex, to obtain high tensile strength without too much weight.” His initial attempts laid the foundations for what would become a major part of his work today, dosing various materials to solve specific technical problems. What began with floating a canoe on water morphed into helping the environment by manufacturing pavements that use less asphalt and energy.

Seizing opportunity

Carter credits his choice of research in large part to one of his professors who helped develop the concrete formulation for the student club. Cognizant of the young man’s qualities, the professor suggested that he complete his construction engineering degree at a French-language school that specialized in energy and materials. Despite not having a scholarship, Carter jumped at the opportunity to perfect his knowledge elsewhere. This proved to be a fortuitous decision. Upon his return to Montréal, he pursued a master’s degree in the burgeoning field of bituminous materials.

This is when the ÉTS made him an offer that he could not refuse: a professor position after three years of studies on asphalt recycling at Auburn University in Alabama. Alan Carter accepted the challenge without hesitation and left for the American university with his wife and baby who was just a few months old. A tireless worker who was able to seize opportunities when they presented themselves, he was now well positioned to spread his wings in a field that he was passionate about.

“In Quebec, we are still resistant to introducing recycled materials into pavements because our winter climate makes it difficult to find a binding agent that works well at low temperatures,” this research professor in the Department of Construction Engineering acknowledges. “Most of the materials contract when it is cold, and asphalt pavement runs the risk of cracking.” Spurred on by this challenge, as co-director of the Pavements and Bituminous Materials Laboratory, he currently oversees myriad research projects aimed at reducing our dependency on asphalt and using less energy to produce pavements.

Finding binding agents other than asphalt

Over time, Carter has tested lignin, a biopolymer found in wood by-products, which has proven to be a viable replacement for traditional petroleum derivatives as a binding agent for pavements. Other trials have been successfully conducted using soy oil, biodiesel produced at the ÉTS, or single-use plastic bags that are otherwise difficult to recycle. This past summer in Victoriaville, for example, part of the asphalt was successfully replaced by this type of material.

“As one of the largest research laboratories on pavements in Canada, we have a major role to play in reducing the carbon intensity of the Canadian economy between now and 2050,” he asserts. “Our research is helping industry and municipalities adopt efficient ways to reduce the environmental footprint associated with road maintenance”. Researchers and students are working as a team to increase the recycled materials used in pavements by up to 40%, while reducing the 150-degree temperature traditionally required to produce asphalt. This is being done not only by optimizing stone skeleton asphalt, but also by using an ideally regenerating bio-binder, such as soy oil, to restore flexibility to the asphalt.

Establishing ties

Carter hopes that his knowledge and discoveries will help reduce greenhouse gas emissions in the transportation field. This motivates him to involve himself in various research groups and learned societies, such as the Canadian Technical Asphalt Association and the International Society For Asphalt Pavement, which bring together specialists from around the world. Far from the image of a researcher ensconced in his ivory tower, he encourages his students early on in their academic careers to establish ties with researchers throughout the world.

In the eyes of this committed educator who has sat on many university committees, “research is part of the training. It is vital to educate as many people as possible so that they can work in the industry or in academia to bring about change. Simply transferring knowledge is not enough. We need to become mentors so that professionals can solve current and future problems.” Ever the optimist about the engineering profession that he sees as well trained, Carter believes that Canada must address the rehabilitation of its aging transportation infrastructure without delay.

He recognizes that infrastructure rehabilitation will require considerable skill on the part of engineers, not only to find innovative and lasting technological solutions but also to be mindful of social and environmental constraints. This vital role will require multidisciplinary teams. Carter is already setting an example for his students by sharing, as much as possible, his knowledge of pavements with global specialists, thereby showing them that the future of engineering rests in large part on the sharing of ideas.