Development of synthetic aggregate using off-ASTM specification ashes

► Synthetic aggregates were produced using off-ASTM specification ashes. ► The optimum water/FBC fly ash for the highest strength was determined to be 0.5. ► The 100% RH and 40 °C were determined to be the optimum curing conditions. ► Both FBC ash and stockpiled ash can be used to manufacture light weight aggregates.