Monthly Archives: June 2003

The Lo Residence Case Study: The Use of High Volume Fly Ash Concrete at the Lo Residence

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This report details The Haebler Group’s use of EcoSmart™ concrete in the construction of the Lo Residence a single-family house located in the Endowment Lands at the University of British Columbia Vancouver British Columbia. The design featured EcoSmart concrete primarily because of its aesthetic appeal. This project was chosen as a case study for EcoSmart in part because of its use of high volume fly ash -HVFA- concrete in horizontal applications.

EcoSmart concrete was used successfully in both horizontal and vertical applications although for the HVFA mixes used in this project the actual quantity of total cementitious material was increased over conventional mixes with a similar strength. Further the HVFA concrete used on this project was found to have a slower set time and higher slump increasing the wall form pressures and causing slab finishing delays. Since premium form design was already incorporated into the construction budget the extra precautions taken in the wall form design and construction did not increase the cost of the vertical elements. However the longer set times did increase the slab finishing costs. Offsetting these costs were the cost savings realized by eliminating sandblasting and other surface finishing because of the excellent quality of “form fresh finish” in the finished wall surface. The cost of the HVFA mix for the vertical applications was equivalent to comparable Type 10 Architectural Quality mixes. In contrast the HVFA mix used in horizontal applications resulted in a cost premium over standard slab mixes because of the increased strength of the HVFA mix.

The most noticeable cold weather concreting problem was darkening and discolouration of the finished and exposed surface. Otherwise the use of HVFA concrete resulted in a fine dense surface texture and light colour consistently throughout construction.

Case Study Report Author: Roland Haebler, Haebler Construction,

Technology Enterprise Facility – UBC Case Study: Using EcoSmart Concrete in Schedule Driven Construction

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This report considers the challenges and successes of using EcoSmart concrete for the Technology Enterprise Facility III -TEF III- LEED-registered project at the University of British Columbia. This report discusses how to overcome the issue of lower early strength and also contains information on early strength test results for mixes used on the project. The use of in-situ tests such as Maturity tests and Lok tests were also considered and Lok tests subsequently tried.

Also discussed in this report is the project s findings that certain elements such as columns and shearwalls could be reduced in size by increasing concrete strength. The benefits of this could be an overall reduction in cement for these elements and earlier stripping. Information on the curing processes used on this project is also included. This project was identified for a case study by the EcoSmart Concrete Project because it addresses the challenges of lower early strengths and curing of EcoSmart concrete.

Case Study Report Author: Diana Klein, P.Eng., Read Jones Christoffersen Ltd,

The Potential Use of Natural Pozzolans in British Columbia as Supplementary Cementing Materials

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Based on a review of existing information the team examined the technical environmental and economic benefits and costs of using naturally pozzolanic materials from provincial deposits as compared with those associated with the use of fly ash from coal-fired thermal electrical power plants as a supplementary cementing material in British Columbia. Based on their findings the team concludes that there is no indication that the natural pozzolans from any of the identified sources in British Columbia have any apparent technical advantage relative to the fly ashes being imported into the province and used as portland cement replacement materials. Further in terms of the present supplementary cementing materials market in British Columbia there would be no environmental benefit derived from using a natural pozzolan instead of fly ash. Finally the delivered cost of a natural pozzolan suitable for use as a supplementary cementing material will be of the same order of magnitude but possibly higher than the price of fly ash in the Greater Vancouver Area market.

Consequently it is recommended that no further investigation of this issue be carried out by the EcoSmartâ„¢ Concrete Project until it can be demonstrated that there is a demand for portland cement replacement materials in the province that cannot be satisfied by the importation of fly ash form Washington State and/or Alberta at an acceptable cost.

Technical Report Author: Robert Gray, Ph.D., P.Eng., James Atwater, P.Eng., W. Dunbar, Ph.D., P.Eng., CMP Technologies Ltd.,

Experiences with EcoSmart: Material Engineer s Perspective

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This presentation introduces EcoSmart concrete in terms of technical issues like strength development effects of admixtures scaling finishing and economics. It uses case study projects to illustrate these technical issues including the Little Mountain Reservoir skytrain stations and the Artist Live/Work Studios -Waterfall Building- .

Presentation Author: Phil Seabrook, P.Eng.