The Mountain Equipment Co-op Montreal store is the Co-op s 8th retail store and the third -after the Ottawa and Winnipeg stores- to comply with Natural Resources Canada s C2000 Green Building Standard. It is the first C2000 compliant retail building in Quebec.

The decision to use EcoSmart concrete was based on the project s environmental objectives. The team initially hoped to use a 50% SCM concrete mix and was surprised to discover that the use of EcoSmart concrete in the MEC Montreal store would be a challenge both in terms of SCM percentage and in terms of cost. The cost premium for HVSCM -high volume supplementary cementing material- concrete in Quebec is related to the limited availability of SCMs in that province other than silica fume. Because most concrete plants do not have an extra silo for storing SCMs most SCM concrete in Quebec is made from preblended SCM cement based on an unvarying formula.

The goal of using a 50% mix was abandoned for budget reasons but MEC agreed to invest the extra money for the 27% mix. When the concrete bids were in the decision was made to use concrete made with Lafarge s Tercem 3000TM blended cement -a blend of 20-25% blast furnace slag 4-6% silica fume and 69-76% Portland cement- . The premium cost for this concrete was $20 / m3 which represents 11.3% of the total concrete cost.

Construction on the MEC store started in October 2002 and was completed in May 2003. The scheduling of the project suffered significant delays due to abnormally cold winter conditions. There was no perceived difference in curing time or workability. The quality of finishing was somewhat disappointing although this was mainly attributed to quality control of the finishing sub-trade rather than the concrete used.

Case Study Report Author: Studio MMA, Atelier d architecture