Stabilized fly ash is a mixture of fly ash and lime, or fly ash and cement, compacted at optimum moisture content and cured to form a product-like soil-lime or soil-cement. Limited past applications and engineering properties of stabilized class f fly ash are discussed. A research study was undertaken to establish the physical, chemical, compaction, strength, and durability characteristics of class f fly ash stabilized with lime, cement, or lime/cement combinations. Two ashes obtained from west virginia power plants were included in the laboratory testing program. It was found that although the ashes are quite different in properties, both ashes can be successfully stabilized to produce pozzolanic mixtures of adequate strength and durability for use as base or liner, with the addition of a proper amount of stabilizer and by allowing the mixture to cure for a sufficiently long period. Cement stabilization, in general, produced better strength and durability than lime stabilization for a given stabilizer content for curing periods up to 56 days. Freeze-thaw cycles caused substantial strength losses, and wet-dry cycles resulted in strength gains. Vacuum saturation with water and an acetic acid solution produced intermediate effects. Very good correlations were found between freeze-thaw and water vacuum saturation tests. This paper appears in transportation research record no. 1288, Geotechnical engineering 1990.
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