Benefits of Slag Cement in HPC

This paper describes how slag cement—commonly referred to as ground granulated blast-furnace slag (GGBFS)—is a hydraulic cement that works synergistically with portland cement to improve concrete strength and durability. Slag cement is a value-added material that results from a tightly controlled production process that ensures consistent physical and chemical properties. Molten slag—the non-metallic mineral constituent of iron ore—is tapped from an iron blast furnace, then rapidly quenched with water in a granulator. The resulting glassy granules are then dried and either ground to a fine powder to make slag cement or interground with portland cement to produce blended cement. Slag cement is different from slag aggregates, which are either air-cooled or expanded blast-furnace slag and possess no cementitious value. Available for many years in the United States, slag cement use has doubled over the last five years.