A coalition of infrastructure groups in Ontario are calling for governments to use more sustainable materials in the construction of public infrastructure projects.

The groups say that a government mandate to include even just 20 percent of recycled crushed aggregates (RCA) for critical construction projects like roads, subdivisions, highways, bridges, and tunnels can save more than $260 million, while reducing greenhouse gas emissions equivalent to removing 15 million cars from the road annually.

"Recycled aggregates are cost-effective, sustainable, and high-performing and can help municipalities deliver more from their capital plans while helping to reach their net-zero targets," said Raly Chakarova, Executive Director of the Toronto and Area Road Builders Association (TARBA). "Using more recycled materials in construction projects can preserve non-renewable resources, reduce waste and traffic congestion, and contribute to long-term sustainability."

RCA is made from reclaimed concrete and asphalt that would otherwise end up in landfills. By adding it to upcoming infrastructure projects, RCA offers significant economic advantages for municipalities struggling to address a growing state of good repair backlog and the infrastructure investments needed to keep up with population growth.

Provincial standards and extensive testing have shown RCA to be as high-performing as primary aggregate, and RCA already has a proven track record in Ontario, including in 400-series highways, at Pearson International Airport, in house-enabling infrastructure in subdivisions, and at Greater Toronto Area transit projects.

"The use of RCA can significantly contribute to the carbon reduction of new concrete used to build our homes, roadways, bridges, and other critical building infrastructure,” said Bart Kanters, President, Concrete Ontario. “The use of RCA in producing unshrinkable Fill (U-Fill) and concrete mud slabs has contributed significantly to environmental sustainability over the past decade. With the update of the CSA A23.1/.2 Concrete standard at the end of 2024, the concrete industry can now utilize up to 30 per cent RCA as a replacement for virgin coarse aggregates in an extensive number of concrete applications."

Across the world, governments are incentivizing the use of RCA through policies and regulations that accelerate the shift toward sustainable construction materials.

A coalition of nine industry organizations – Concrete Ontario, Good Roads, the Greater Toronto Sewer and Watermain Construction Association (GTSWCA), Heavy Civil Association of Toronto (HCAT), Ontario Road Builders Association (ORBA), Residential and Civil Construction Alliance of Ontario (RCCAO), Ontario Sand, Stone, and Gravel Association (OSSGA), Ontario Society of Professional Engineers (OSPE), and Toronto and Area Road Builders Association (TARBA) – is advocating for municipal and provincial decision-makers to take the lead in Ontario and maximize RCA's economic and environmental benefits.

At the municipal level, the groups are calling to include the use of RCA in tenders for construction projects, mandate a minimum amount of RCA for all public infrastructure projects, and harmonize municipal specifications for RCA through provincial standards.

At the provincial level, they are calling for the government to incentivize the use of RCA through funding for municipal infrastructure projects, to prohibit municipalities from specifying "primary-only" in public infrastructure tenders, to harmonize municipal specifications for RCA through provincial standard, and to mandate a minimum 20 percent RCA of aggregates used on all municipal, regional, and provincial public infrastructure projects.

The groups say 180 million tonnes of aggregates are used annually in Ontario, with more than 50 percent used in roadways, bridges, and tunnel construction. However, less than seven per cent of those aggregates come from recycled sources, most attributed to the Ontario Ministry of Transportation's construction and expansion of 400-series highways.

Municipalities are the largest aggregate consumers in the province, using between 60 and 70 million tonnes a year.

The GHG emissions savings for every 10,000 tonnes of aggregate that is recycled instead of newly extracted aggregate is equivalent to taking 137 gas cars off the road per month, saving 21,000 pounds of coal, or planting 315 tree seedlings that grow for 10 years.