PROPERTIES OF HIGH FLY-ASH CONTENT CELLULAR CONCRETE

High fly ash content autoclaved cellular concrete is produced by addin g calibrated quantities of aluminum powder to a mixture of fly ash (60 % wt/wt), cement, and water. The foamed product is hardened in an auto clave with pressurized steam at about 180-degrees-C. Block material fo r samples tested originated from a mobile pilot plant that toured site s of United States-based electric utilities. Compressive strengths of the foamed product were controlled to the range of 300-600 psi, with d ry weight densities on the order of 32-37 lb/cu ft. Heavy metal concen trations in TCLP, ASTM, and synthetic acid rain leachates were on the order one to 10 times that found in Pittsburgh tap water, and never ap proached 100 times drinking water standards. Organic contents of leach ates were not detectable. Controlling pore distributions appears to in fluence density, moisture accumulation rates, and mechanical/physical properties that are significant for construction.