Durability of concrete using granulated blast-furnace slag as a mineral admixture

Abstract

Granulated blast-furnace slag (GBFS) is a by-product of iron and steel-making from a blast furnace. In Vietnam today, granulated blast furnace slag is mainly ground with clinker to produce portland blended cement. The use of  ground-granulated blast furnace slag (GGBFS) as a mineral admixture for concrete is still a new issue. This paper presents the effect of ground-granulated blast furnace slag, which was used as a mineral admixture on some properties related to the durability of concrete such as waterproofing, chloride ion impermeability, sulfate resistance and aggregate alkali reactivity. Concrete use GGBFS as a mineral admixture with the ratio of GGBFS 20 % to 70% with the control-cement PC40. Research results show that using GGBFS to partially replace cement can improve chloride ion impermeability resistance, waterproofing and ability to prevent the aggregate alkaline reaction of concrete. In addition, using GGBFS also improves the sulfate resistance of mortar specimens, which were immersed in a sulfate solution (Na₂SO₄).