Compressive strength, resistance to chloride-ion penetration and freezing/thawing of slag-replaced concrete and cementless slag concrete containing desulfurization slag activator

Abstract

In this research, desulfurization slag (DS), a byproduct generated during steel production, was used as an activator for ground granulated blast-furnace slag (GGBS), and the compressive strength, resistance to chloride-ion penetration and freezing/thawing of slag-replaced concrete and cementless slag concrete containing DS activator was evaluated. The experimental results indicated that DS affects the strength development of slag-replaced concrete and cementless slag concrete when used as an activator. Moreover, a constant increase in the compressive strength was observed during the long-term aging of cementless slag concrete with a DS and anhydrous gypsum mixture. However, the transformation of ettringite to monosulfate was not effective; a large quantity of ettringite was observed at a long-term age of 910days in the cementless slag concrete. In addition, a high resistance to chloride-ion penetration was obtained for high-volume slag concrete. The resistance to chloride-ion penetration was greater in cementless slag concrete. On the other hand, cementless slag concrete, which had a high volume of capillary pores, had the lowest resistance to freezing/thawing.