This paper discusses the use of high levels of fly ash in concrete as part of a â€œGreen Buildingâ€ at York University in Toronto. In most of the concrete mixes used for the building 50% of the Portland cement was replaced with CSA A23.5 type CI fly ash an industrial by-product from Ontario. Despite the significant reduction in the cement content the concrete produced comfortably met the specified strength requirements was easy to place and finish and its use had no impact on the construction schedule. Such concrete may be suitable for many other commercial or residential construction applications although the material does require some special consideration -e.g. regarding curing- especially when used in a severe exposure condition. This paper discusses the environmental economic and technical issues of using high contents of fly ash in concrete construction.
Technical Report Author: D.S. Hopkins, M.D.A. Thomas, D.B. Oates, Gurinder Girn, Robert Munro