Recycle your wine bottles and watch them transform into bridges, sidewalks

In a time of push for bigger and better infrastructure, Quebec researchers are working toward an environmentally friendly way to build bridges and construct sidewalks.

The answer: glass powder used from millions of wine and spirit bottles thrown into recycling bins.

This finding has led to the creation of the SAQ Chair, a collaboration between the Société des alcools du Québec (SAQ), the Université de Sherbrooke Foundation and more.

The Chair, led by Sherbrooke University civil engineering professor Arezki Tagnit-Hamou, aims to add mixed glass to concrete to highlight sustainable development, environmental protection and economic and social considerations.

The process of creating glass powder, according to Tagnit-Hamou, is simple.

"They have to clean it, then they develop a grinding centre...they have to grind it very fine," he said. "The fineness is around the same fineness as cement or even less."

Tagnit-Hamou points out glass is originally created by heating sand at high temperatures.

"By doing that, you create a reactive material," he tells CTV News. "When you replace a part of cement by glass powder, this glass powder will produce almost the same glue like cement."

Tagnit-Hamou explains that research shows that adding glass powder to concrete instead of cement makes it much more durable, waterproof and resistant.

It also significantly reduces the greenhouse gas (GHG) emissions associated with its production.

"The CO₂ emission can be huge because one tonne of cement can produce around 800 kilograms of CO₂," he said. "In all the world, we have around 4.6 billion tonnes of cement."

Tagnit-Hamou states concrete is one of the planet's most widely used construction materials -- after water.

"The industry has to find a solution to decrease the CO₂. This is the reason why this type of material, like glass, is very interesting," he said. "Not only to decrease the glass in the sorting plants but definitely to also decrease the CO₂ emissions in the concrete industry."

According to the SAQ Chair, for each tonne of glass powder added to concrete as a cement additive, GHG emissions are reduced by around 0.6 tonnes.

Tagnit-Hamou explains glass powder can replace up to 40 per cent of cement.

"In Quebec, we work a lot with 10 and 20 per cent. Some of our friends in the U.S. work with 20 to 40 per cent," he notes.

He says this difference is partially due to Canada's more drastic climate.

The plan, Tagnit-Hamou adds, is to slowly increase the glass powder percentage to match that of the U.S.

Since its creation, the Chair has focused on standardizing glass powder as a cementitious material both in Canada and America.

Several projects have already been completed using glass powder concrete.

Most notably, the Darwin Bridge in Île-des-Sœurs used the equivalent of 70,000 wine bottles, saving 40,000 kg of cement.

The project, which was a world first, piqued the curiosity of the global science community, winning the Infrastructures 2021 Award of Excellence.

The technique has also been used to pave numerous kilometres of sidewalks across Quebec and some SAQ store floors.

The program boasts numerous partners, including Hydro-Quebec and the cities of Montreal and Sherbrooke.