Evaluation of Chloride Penetration in Concrete with Ground Granulated Blast Furnace Slag considering Fineness and Replacement Ratio

Abstract

Durability performance in RC structures varies significantly with changes in cover depth and mix proportions. GGBFS (Ground Granulated Blast Furnace Slag) is very effective mineral admixture and widely used for an improved resistance to chloride attack. In this paper, characteristics such as porosity, compressive strength, and diffusion coefficient are evaluated in GGBFS concrete with 30∼ 70% of replacement ratio and 4,000∼8,000cm 2 /g of fineness. Through the tests, more dense pore structure, higher compressive strength, and lower diffusion coefficient are obtained in GGBFS concrete, which are evaluated to be more dependent on replacement ratio than fineness. With increasing curing period from 3 to 91 days, porosity decreases to 77.47% and strength increases to 373% in GGBFS concrete. Chloride diffusion coefficient in GGBFS concrete decreases to 64.4% compared with that in OPC concrete, which shows significant improvement of durability performance.