Recycled Crushed Aggregate

Yes, both asphalt and concrete are 100% recyclable. These products can be crushed, cleaned and screened, and reused as valuable construction material. 

Every year, tens of millions of tonnes of asphalt and concrete are removed from construction sites across Ontario as roads are repaired, bridges are maintained, and other critical infrastructure is replaced.

RCM (recycled concrete material) and RAP (recycled asphalt pavement) are processed and reused as aggregate – for example in road bases, shoulders and backfill. RAP can also be reused in making new hot mix asphalt.

A total of about 184 million tonnes of aggregate are used annually in the province. New aggregate (from quarries and pits) meets most of this demand. Only about 13 million tonnes or 7% come from recycled sources.

Ontario’s Ministry of Transportation uses about 20% recycled materials in its 400-series highway construction. According to a report by the province’s Environmental Commissioner, Ontario could avoid extracting up to 33 million tonnes of new aggregate a year if a similar recycling rate could be achieved at the municipal level.

In contrast, some other countries use up to 90% recycled aggregate.

The Ontario Provincial Standard Specifications (jointly administered by the Ontario Ministry of Transportation and the Municipal Engineers Association) set the standards for road construction and materials in the province. Despite Ontario’s provincial standards, municipalities have discretion in the implementation of these standards and in their local policies. As a result, practices can vary widely by municipality, even in an economically significant region as the Greater Toronto Area, with many choosing to prohibit or severely limit the use of recycled aggregate in road construction and other public works.

This is especially problematic because, collectively, municipalities are the largest consumers of aggregate in the province, using between 60 and 70 million tonnes a year.

They may not be familiar with the facts about recycled aggregate or lack experience. As long as the recycled asphalt and concrete conform to OPSS1010, municipalities can be confident that these materials will meet all performance requirements and quality expectations. As responsible owners, they should also do their own quality assurance testing to confirm quality.

If not recycled, these valuable materials end up in our landfills, further exacerbating existing capacity issues. If recycled, but not used, these products end up being stockpiled in growing mountains of urban rubble or, once again, dumped in landfill. Either way, that’s a terrible waste of a precious resource.

By using more recycled aggregate, which is located close to major construction projects, the need to haul new aggregate from distant quarries is dramatically reduced. This substantially lowers energy consumption and greenhouse gas emissions. It also:

• Keeps aggregates out of the waste stream.
• Reduces pressure to develop and expand pit and quarry operations.
• Results in lower project costs and building more sustainable infrastructure.

Municipalities and other project owners should consider sustainability as part of the initial project design, including in their tenders the ability for contractors to use recycled materials that meets OPSS1010 specifications.

The Ontario Provincial Standard Specifications (jointly administered by the Ontario Ministry of Transportation and the Municipal Engineers Association) set the standards for road construction and materials in the province. OPSS1010 allows aggregate used in road bases, shoulders and backfill to be composed of up to 100% recycled concrete and up to 30% recycled asphalt. Hot mix asphalt can contain up to 30% recycled asphalt pavement.