Canada Bridge Construction Uses Recycled Glass


Officials working on the Darwin bridge project on Nun’s Island in Montreal, Canada, have reported that the structure is incorporating recycled glass in its materials.

While recycled glass has been used in the City of Montreal for concrete-based sidewalks and store floors, the city reports that the bridge is the first in the world to use the recycled material for this form of infrastructure.

Infusing Recycled Glass

In following a pilot project conducted in partnership with the SAQ and the Université de Sherbrooke, researchers landed on the idea that using powdered recovered glass in a road bridge is just the latest in how the material can be advanced.

Marie-Hélène Lagacé, SAQ Vice President, Public Affairs, reported that the new use in construction arrives after more that 15 years of research and development by the partnership, in searching for new methods to use the glass bottles it sells.

Not only does the recycling option help the company itself, but also helps local landfills, which have been reportedly overflowing with recycled materials such as glass.

Posted by Canadian Environmental Law Association (CELA) on Thursday, October 22, 2020

According to lead design engineer on the Darwin bridge project, Étienne Cantin Bellemare, an estimated 70,000 recycled glass were ground into a fine white power and has accounted for 10% of the material used, saving roughly 40,000 kilograms (about 88,185 pounds) of cement.

“We found out the results are very good so this material performs very well in our climate,” said Bellemare, adding that the powder replacement not only makes the concrete more durable and resistant, but also reduces its environmental footprint.

“This is going to lead to a CO2 reduction of 40 metric tons,” Bellemare said.

Construction on the eastbound lane is slated for completion by the winter, with both lanes expected to open by next fall. After construction is completed, Bellemare adds that officials will be studying the structure and how it performs over the next few years.

If the use of recycled materials prove successful, they expect recycled glass will be used in more infrastructure projects throughout the world.

Other Glass Studies, Uses

While the use of recycled glass hasn’t yet gained momentum in the infrastructure sector, back in 2016, Canadian researchers reported the ability to calm a chemical reaction that has traditionally caused glass-fed concrete to weaken, expand and crack, a reaction known as “concrete cancer.”

The team from the University of British Columbia Okanagan campus reported at the time that it had found a more reliable way to make concrete from discarded glass and its findings were published in the journal Construction and Building Materials.

In their study, Associate Professor of Engineering Shahria Alam and co-researcher Anant Parghi discovered that by adding a water-based, synthetic rubber polymer, fly ash, and silica powder to the concrete mixture, they were able to effectively neutralize negative chemical reactions.

“By partially replacing cement with polymer, fly ash and glass powder, we were able to produce concrete that was more than 60% stronger than what was previously believed possible,” said Parghi. “Though further testing is needed to assess long-term stability, it now looks like we can replace up to 25% of the cement materials that had to be mined for cement production with glass.”

All of the glass used in the study was taken from the landfill in Kelowna, BC, and was considered waste at the time it was retrieved. The concrete additives were donated from Kelowna-based company POLYRAP Engineered Concrete Solutions.

The following year, abrasive manufacturer Strategic Materials (Houston, Texas) found another way to recycle glass for the industry, through a new abrasive it developed, comprised of 100% recycled glass.

TruAbrasives premiered its new line of air blast abrasive product, taking the place of New Age Blast Media, a previous brand that Strategic Materials acquired in 2015. New Age Blast Media was phased out over 2018.

Because it is made of crushed glass, Strategic Materials says, the new abrasive does not carry some of the risks associated with other abrasives, which can put workers in danger of health problems from respirable crystalline silica and metals like beryllium. Additionally, because the glass the abrasive is made of is recycled, the company points out that it brings environmental benefits with it.


Tagged categories: Bridges; Construction; Environmental Controls; Glass; Infrastructure; Infrastructure; NA; North America; Project Management; Recycled building materials; Research and development

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