Lafarge Canada Inc. has completed the initial phase of its ECOCycle pilot project – integrating demolition waste into cement production at its St. Constant facility near Montreal.

The project has integrated approximately 10,000 tonnes of recycled concrete and building demolition material into the manufacturing process for new cement over the past year. The company states the cement is of equivalent performance to traditional methods and meets all local requirements. It has been incorporated into construction projects in the Greater Montreal Area.

According to a release, an estimated 10 million tonnes of construction and demolition waste is generated each year in Canada, with four million tonnes being concrete.

The pilot was undertaken in collaboration with fellow Holcim Group subsidiary Geocycle. Holcim launched ECOCycle in April 2023. According to a release, it can reuse 100 per cent of construction demolition materials across several applications, from decarbonized raw materials in low-carbon cement formulation to aggregates in concrete and fillers in road construction.

“ECOCycle technology is a proprietary collection of means to utilize construction and demolition materials for the renewed manufacture of cement. The majority of the material is concrete that is sourced from demolition of pond construction projects and then fed at the cement plant into the process to make cement,” Andrew Stewart, Lafarge Canada (East)’s vice-president of cement, told SustainableBiz via email.

“The chemical and physical properties of the material allows for circularity.”

The ECOCycle St. Constant pilot project

Part of the reason the St. Constant plant was chosen was practicality, as much of the equipment was already in place.

“Additionally, the pioneering spirit at this site to improve and learn is strong, another example being employing recycled biomass and non-recyclable plastic application for cement production, cutting down over 91,000 tons per year of CO2 (carbon dioxide) emissions in 2020,” Stewart said.

“This project is the next exciting chapter in our journey towards a circular economy.”

Geocycle managed the processing of the waste materials and other alternative resources.

“(Geocycle) specializes in efficient and eco-friendly waste solutions through co-processing in cement kilns,” Stewart said. “Collaborating with a fellow member of the Holcim Group was a logical step, underlining our dedication to responsible construction materials processing.”

While he did not divulge specifics, Stewart said this also involves a potential reduction in emissions, given that waste concrete has a lower embodied carbon dioxide percentage than other cement-making materials.

The goal for the project was to generate 5,000 tonnes of reused material. Lafarge managed to double that, achieving 10,000 tonnes, according to Stewart. The company will be looking at ways to improve on this result as it refines the process.

Future ECOCycle plans

Stewart stated there are numerous ongoing projects to increase the use of ECOCycle technology at Lafarge and across Holcim.

“Certainly, our plan is to expand beyond the initial 10,000-tonnes phase. This initial phase allowed us to assess construction demolition material's viability in cement production and its potential for concrete projects,” Stewart said.

“Our success in achieving performance parity and forming collaborative partnerships underscores the initiative's promise.”

According to a Holcim release in April, it is building the world’s first affordable housing complex in France with 100 per cent ECOCycle. In the U.K., Holcim is building a residential area utilizing materials that are half ECOCycle aggregate.

ECOCycle isn’t the only sustainability initiative Lafarge has in motion.

In July, Lafarge converted all production at its Richmond, B.C. cement factory to ECOPlanet low-carbon cement, becoming the first Holcim-owned facility worldwide to make the transition.