Engineering and Microstructural Studies of Western-Canadian Fly Ash Bricks

An experimental programme was undertaken to determine whether Canadian fly ash, and in particular Western-Canadian fly ash, can be used to replace clay as the main ingredient in brick-masonry units.These preliminary examinations show that Western-Canadian fly ash as the solid material, combined with an adequate binder, can be used to produce a superior ceramic material. Strengths are very much higher than that revuired for load-bearing masonry elements, densities are approximately 800 kg/m3 less than a normal clay brick and the material is durable to freezing and thawing. X-ray analysis and scanning electron microscopy clearly show chemical and physical changes which occur to the material due to firing. These chemical changes appear to be closely related to the subsequent strength which is developed.Bricks manufactured from Alberta fly ash appear to be a viable alternative to standard clay brick. A substantially stronger and more economical brick may be possible; fly-ash bricks can be manufactured with lower firing temperatures of shorter duration. This, in itself, could lead to the realization of significant energy savings. Also, if large quantities of fly ash can be used in the brick industry, then significant gains will be made toward the elimination of this waste product from the environment and conservation of natural resources.