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Crushing it: repurposing excavated rock to create sustainable solutions at The Ottawa Hospital’s new campus site 

Jul 23, 2024

 

Contributing to planetary health and environmental sustainability is one of seven planning principles in the design and development of The Ottawa Hospital’s new campus. 

As The Ottawa Hospital works to finalize plans for the new hospital, there have been many visible changes on the site of the new campus, with construction of the parking garage well underway.  

Excavation efforts last summer and fall removed approximately 66,000 cubic metres amount of rock to clear the area for the parking garage to be built. This material is typically hauled away from construction sites by trucks for processing before it’s returned to be used to backfill. Instead of hauling the excavated rock offsite to be broken down for backfill later in the project, TOH chose to repurpose the excavated rock on site.   

“Crushing rock onsite prevented the need for about 8,000 truck loads leaving and then returning to the site with crushed material,” says Dwight Breault, Director of Construction Management for The Ottawa Hospital’s New Campus Development. “With the help of a rock crusher, we were able to do the job onsite and avoid unnecessary back and forth of heavy load dump trucks, which in turn helped support our efforts to be as sustainable as possible and provided some cost savings.”

A rock crushing machine in action on the site of The Ottawa Hospital’s new campus. (Fall 2023)

Rock crushing 101: the nitty gritty 

Typically used in the construction of buildings, bridges and highways, a rock crushing machine uses compression to exert force and break down large rock into smaller pieces called aggregate. The aggregate is then stockpiled and used as backfill and as needed to support structures being built.  

To date, construction teams onsite at the new campus have processed and stockpiled approximately 66,000 cubic metres of rock cleared during excavation. For a visual comparison to get a sense of size, that’s more than 11 times larger than the Goodyear Blimp! While we’re talking numbers, 66,000 cubic metres of rock weighs approximately 165,000 metric tonnes. By reusing it onsite, construction teams reduced the need for additional aggregate resources that would need to be purchased and hauled to the site.

Most of the rock crushed on site is being used as backfill in the construction of the parking garage that will support our new hospital. TOH is seeking other opportunities to reuse or repurpose natural elements being moved during development, including rock, soil and trees.

Learn how we’re integrating a focus on sustainability into new campus designs.