Identifying the role of fly ash properties for minimizing sulfate-heave in lime-stabilized soils

► Three clays of varying sulfate level and seven fly ashes covering a range of properties tested in lime-stabilized mixes. ► Coarser compacted soil structure obtained with higher fly ash levels and coarse, high loss-on-ignition (LOI), wet-stored material. ► Sulfate-induced heave (swelling) reduced with higher fly ash levels and coarse, high LoI, wet-stored material. ► High sulfate levels in fly ash reduce effectiveness of material in minimizing heave. ► Suggested methodology given for fly ash selection to minimize sulfate-induced heave.