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

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,