Appendix A to the Mountain Equipment Co-op case study report is a brochure describing Lafarge s Tercem 3000 cement. This cement was used in the MEC Montreal building. The benefits of Tercem 3000 include higher ultimate strength reduction in permeability improved rhealogy and better finishability. The cement is produced by intergrinding Portland cement clinker gypsum silica fume and pelletized blast furnace slag.
Technical Report Author: Lafarge Canada Inc.
Cedar Corner development in Tofino B.C. is a LEED-registered project in which construction was based on sustainable principles. The project consists of a three level structure to be utilized for mixed commercial space including a pub and restaurant. The entire structure was built from recycled building materials and high volume fly ash -HVFA- concrete was utilized for all of the concrete which included footings basement walls grade and suspended slabs.
The placement of the concrete went well despite the crew having no previous experience with EcoSmart concrete. There were a few problems during the pour particularly the uniformity of the concrete slump and the excessive bleed water and the concrete was slower to set than expected. However this was likely because the recommended accelerator was not used and the batch plant did not have an adequate water control system so the net mixing water was higher than it should have been.
This report provides details of the test reports concrete properties mix properties and mix proportions as well as several photographs.
Case Study Report Author: Kyle Dolan, E.I.T., Levelton Consultants Ltd,
Cedar Corner is a LEED-registered restaurant and brewpub in Tofino BC. The building owners decided that the building should be a showcase for green design which led to the building being constructed out of recycled timber water and energy efficient fixtures and designs and non toxic building materials. A goal of 50% fly ash substitution was targeted for the concrete used on this project although ultimately a mix of 40% fly ash was used.
The crew had no problems placing or finishing the EcoSmart mixture. The mix performed well and showed no signs of segregation during placement. However there were problems with excessive bleed water and the uniformity of the slump both likely due to the method of mixing the fly ash bags into the back of the truck. There was also a cost premium associated with the use of fly ash because the suppliers did not have their own equipment to handle delivery storage or shipping of the fly ash. Overall though the mix performed well and gave a superior product that is more durable and polishes to a finer finish than regular concrete.
Case Study Report Author: Guy Dauncey
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
Michel de Spot chair of the EcoSmart Concrete Project presented this paper at the US Green Buildings -USGBC- in Pittsburgh November 2003.
Concrete a material synonymous with strength and longevity is a leading and universal material that is used in all types of construction. However Portland cement a key constituent of concrete has a significant environmental impact: the making of every tonne of clinker the base for Portland cement produces a similar amount of carbon dioxide -CO2- a greenhouse gas as a by-product which is released into the atmosphere.
The EcoSmart™ Concrete Project’s objective is to minimize the greenhouse gas -GHG- signature of concrete by replacing Portland cement with supplementary cementing materials -SCMs- such as fly ash to the greatest extent possible while maintaining or improving cost constructability and performance. The Project is an innovative industry-government partnership that aims to increase awareness of the benefits and challenges of EcoSmart concrete through case studies applied research and communication to the point where the technology becomes common practice. EcoSmart has demonstrated through a number of case studies that replacement levels of 50% are achievable within the parameters of cost constructability and performance particularly when appropriate design methodologies and construction practices are used.
Implementation of this technology in the field is one of the biggest challenges for EcoSmart. The LEED rating system potentially offers an incentive to specifiers to increase the use of SCMs in development projects. However in order for the LEED system to realize this potential it must first recognize the full environmental benefit of SCMs within its credit system.
Presentation Author: Michel de Spot, P.Eng.