Winnipeg’s recycled concrete aggregates specification needs work, MHCA

A report prepared by a City department for a Council committee on the use of recycled concrete aggregates in 2021 roadbuilding reflects only the views of administration, not industry, MHCA President Chris Lorenc said.

The report was presented to the Infrastructure Renewal and Public Works Committee January 13, triggering a vigorous debate about the pros and cons of using recycled concrete aggregates (RCAs).

The MHCA said the report did not have benefit of input from a working group that was to advise on the new specifications for roadbuilding.

“The Specification Review Committee established by IRPW to allow for industry/stakeholder-based input into the introduction of new or adjustment of existing specifications was not convened nor consulted ahead of the report being written,” said Lorenc. “Therefore, the Committee cannot be aware of the information upon which the report’s conclusions and recommendations are based.

“Our industry and many others see real opportunity for broad use of the crushed concrete taken up from reconstruction of city streets each year. We cannot consign these materials – aggregates that are reusable – to the landfills to become an environmental liability.”

Moreover, he noted, we all have a responsibility as stewards of finite resources to manage them prudently. “Depositing them as waste to landfills without considering their reuse is inconsistent with that responsibility and flies in the face of the City’s own Climate Action Plan.”

The department’s report noted that some 32,000 tonnes of RCA were used in the 2021 construction season, but 55,000 tonnes of concrete were pulled up from streets under renewal or reconstruction. While the report says all material was taken to recycling facilities run by suppliers, the industry notes that there are substantial stock piles mounting in the yards – recycled aggregates looking for a place to be used.

The IRPW decided to lay over consideration of the report until the next meeting in February. Committee Chair Matt Allard said he did not want to support a recommendation to continue to allow the use of RCAs in some aspects of the street renewal program; other councillors said they needed to hear the view of industry to better understand the implications of constraining the use of RCAs in the building of roads.

Lorenc said IRPW’s direction to the Public Works department in 2020 was to work with the industry, the Spec Review Committee and the University of Manitoba (construction engineering) to recommend ways to increase the use of RCAs in roadbuilding – the report before IRPW does not do that.

“Testing on the RCAs as material for use in the construction of road base and sub-base is continuing; the Spec Review Committee is not finished its work. We have to find a way to make RCAs a common product for building roads, sidewalks, laneways and many other infrastructure projects that the city and the private sector undertake,” Lorenc said.

The MHCA sent an email to the IRPW councillors expressing concerns and noting that they are in a position to give direction now, regarding the IRPW Committee’s directive that Public Works come back to it with a recommendation to increase the use of RCAs in road base design.