ACI 226.1R : 1987

The use of iron blast furnace slag as a constituent of concrete, either as an aggregate or as a cementing material, or both, is well known. The use of ground granulated blast furnace (GGBF) slag in the production of blended cements began in 1905 in the United States. Recent attention has been given to the use of GGBF slag as a separate cementitious constituent of concrete. This report primarily addresses the use of GGBF slag as a separate cementitious material added along with portland cement in the production of concrete. Other slags derived from the smelting of materials other than iron ores are not discussed in this report. The reader should be aware that the material characteristics described and the recommendations for use pertain solely to ground granulated iron blast furnace (GGBF) slag.