On-Site Magazine

The 3 Rs of aggregate recycling

By Corinne Lynds   

Concrete Construction Construction Materials Green Construction LEED Roads aggregates infrastructure recycling

shutterstock_137829401Efforts to launch a certification program for aggregate recycling facilities in Ontario stalled last month when partner associations and producers raised concerns at the 11th hour.

Aggregate Recycling Ontario (ARO) has spent the last year and a half implementing a certification program for its members’ aggregate recycling facilities. ARO believes that recovered aggregate materials from road construction and demolition projects should be re-engineered and reused as recycled aggregate in new construction projects.

Brian Messerschmidt, executive director of ARO explains that the certification program was initiated to build confidence in consumers of recycled aggregates. “Part of that was to develop and enhance a version of best practices that members would undertake. This includes having a quality program in place to show that they are checking materials coming in and going out,” he says. “We got to the point of ready to roll it out, then some of the members said ‘oh geeze, now that we’ve taken a closer look, we’re not sure we’re in favour of this when we don’t have assurances from the municipalities that if we go to all this trouble, that they are still going to buy our product.”

So, after a meeting of associations and producers on February 12, the decision was made to slow things down a bit. “We want to enter into a consultation process with the municipalities. We will consult with municipal associations, including the Municipal Engineers Association and the Ontario Good Roads Association, and directly with several key municipalities,” says Messerschmidt. “The objective is to determine what they feel are the necessary steps for the industry to take to build municipal confidence that recycled aggregate products meet quality expectations.”


Messerschmidt explains that there are a number of secondary materials or industrial byproducts that are capable of substituting for primary or virgin aggregate, but ARO is particularly focused on increasing the use of two materials: RCM (recycled concrete material), and RAP (recycled asphalt
pavement). He points out that Ontario’s 444 municipalities collectively are the
largest consumer of aggregates in the province. They consumed between 60 and 70 million tonnes of the total 152 million tonnes that were consumed in Ontario
in 2014.

A little history

Aggregate Recycling Ontario was established in July 2011 to provide a unified platform for industry stakeholders that recover, recycle and consume aggregate materials in Ontario. Initiated by the Ontario Stone, Sand & Gravel Association and the Toronto and Area Road Builders Association, the organization was formed to bring attention and find a solution to the province’s growing aggregate piles, as well as expand the opportunities for recycling aggregates.

Across the province, millions of tonnes of aggregate recovered from construction sites are stockpiled and ready to be used in new road construction projects. Although the provincial government—through the Ministry of Transportation—and some municipalities have been leaders in using recycled aggregates for several years, many municipalities’ specifications do not allow for recycled aggregates to be used in construction projects. Processed properly, recycled aggregates meet all performance requirements and offer a suitable alternative to primary aggregates. 

ARO is made up of 16 aggregate producers and seven supporting associations.

Economic and environmental perspective

Re-using concrete materials makes sense from both an environmental and economic perspective. The use of recycled aggregate preserves non-renewable resources, reduces our need for new quarries and pits, reduces energy use and greenhouse gasses associated with longer truck hauling, and can be supplied locally and less expensively than primary aggregate.

Aggregate recycling facilities provide contractors with a location to recover reclaimed concrete material, without disposing of it in landfills or using it as clean fill, saving money in disposal fees. Properly processed, or re-engineered, recycled aggregate that meets Ontario Provincial Standard Specifications (OPSS), is a suitable material for use in road construction, as engineered backfill and as a base material in many other applications. Used appropriately, recycled aggregate performs as well or better than primary aggregate.

The winding road to certification

The recent decision to slow things down doesn’t mean ARO is abandoning its certification program. There will likely be amendments once the municipalities have been consulted, but the association has already developed key information in support of the program. At www.aggregaterecyclingontario.ca there are several documents available in support of the certification program, including: The Best Practices Guide, Recommended Quality Control Requirements, Audit and Check List, and a list of 10 accredited third-party engineers trained specifically to perform audits.

Ultimately, ARO’s mission: to ensure that aggregate material is recovered, re-engineered and re-used in new construction projects, remains the same. Whether this is accomplished through best practices, or a formal certification program is still to be determined.

“It’s a bit of a chicken and egg scenario, as we could come out with having everyone certified and then still have municipalities that are reluctant to include our products. And so this is a step to ensure that if we go to all of this trouble [to certify] that municipalities are going to do their part
as well.” 

With files from www.aggregatesrecyclingontario.ca. Send comments to editor@on-sitemag.com


Stories continue below