EcoSmart Concrete in the Quebec Context: Mountain Equipment Co-op, Montreal

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

Advancements in Concrete Technology

In terms of advancements in concrete technology the driving forces have been durability and speed of construction. However the environmental impact of construction materials is becoming an increasingly important driver. In this paper Mehta evaluates concrete technologies using the criteria of construction speed durability and environmental impact. One of the technologies he examines is high volume fly ash and slag concrete particularly in terms of their use in structural concretes roller compacted concrete dams concrete pavement for highways and base courses and embankments.

Technical Report Author: P. K. Mehta

Current Situation of Supplementary Cementitious Materials (SCMs) in Canada

The report details the current situation of supplementary cementing materials -SCMs- in Canada specifically in terms of production cost availability usage potential areas for increasing usage local barriers and relevant guidelines and specifications. The purpose of the study is to determine a strategy to increase the use of SCMs in Canada.

The data show that approximately 524 000 347 000 and 37 000 tonnes of fly ash Ground Granulated Blast Furnace Slag -GGBFS- and silica fume were used in cement and concrete applications in 2001. These amounts represent 11 90 and 185% of the quantity produced respectively. Thus fly ash appears to be the only material that is underused and that represents a potential for increased use of SCMs in Canada.

The investigation also shows that there are policy technical and economic barriers to the increased use of SCMs in Canada. The report suggests several solutions to overcome these barriers.

Includes an extensive list of tables.

Technical Report Author: Nabil Bouzoubaa, Benoit Fournier

The Role of Superplasticizers in the Development of Environmentally-Friendly Concrete

Since their introduction in the early 60’s superplasticizers have become an essential component of concrete. By reducing the amount of water in concrete superplasticizers have contributed to a significant reduction in its porosity and to a concomitant increase in its compressive strength and durability. These chemical admixtures have also been at the forefront of the use of mineral admixtures such as silica fume fly ash and blast-furnace slags in high performance concrete. By making possible the use of these industrial by-products as a partial replacement of cement superplasticizers are also helping to reduce the emission of CO2 in the atmosphere a key issue in several industrialized countries.

This paper reviews some important aspects related to the use of superplasticizers in concrete. More precisely it concentrates on how these polymers contribute to sustainable development by favoring the use of mineral admixtures in concrete and by increasing the durability of concrete structures.

Technical Report Author: Monique Page, Nelu Spiratos