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U.S. Department of Energy
Office of Scientific and Technical Information

Roller compacted base course construction using lime stabilized fly ash and flue gas desulfurization sludge by-product

Conference ·
OSTI ID:370345
 [1]
  1. Dravo Lime Company Research Center, Pittsburgh, PA (United States)
Dewatered calcium sulfite and calcium sulfate sludges from flue gas desulfurization (FGD) processes at coal fired power plants can be mixed with coal fly ash and lime to cause a cementitious chemical reaction used to construct a roller compacted base course or an impermeable pond liner. Tile chemical reaction is often shown as lime reacting with alumina from the fly ash which in turn reacts with the calcium sulfite and sulfate FGD waste to form sulfo-aluminate. Better understanding is needed of the controlling factors that result in a successful application of this chemical reaction which has been linked to past construction failures due to latent hydration causing expansion damage or degradation of concrete, called sulfate attack. Factors such as optimum moisture content, fly ash to FGD ratio, and age of FGD are examined that affect strength gain and freeze-thaw durability. Several recently completed field demonstrations are discussed.
OSTI ID:
370345
Report Number(s):
CONF-960376--
Country of Publication:
United States
Language:
English