Concrete Performance with Ground Granulated Blast Furnace Slag as Supplementary Cementitious Materials

Abstract

Supplementary Cementitious Materials (SCMs) are materials that contribute to the hardened concrete properties through hydraulic or pozzolanic activities. The use of Ground Granulated Blast Furnace Slag (GGBFS) as SMCs or partial replacement of cementitious components in concrete provides benefits both in terms of economy and performance improvement. However, GGBFS is not widely known in Indonesia, hence the available research for this product is still limited. In this study, the performance of concrete with GGBFS as a partial replacement for cement was investigated, with the percentage of GGBFS varying by 0%, 30%, 50% and 70% of cement weight. The mechanical properties of concrete being observed are compressive strength and elastic modulus. Porosity testing is carried out to assess the durability aspect of concrete. Compressive tests are carried out when the concrete age reached 7, 28, 56 and 90 days to assess the strength development of GGBFS based concrete. From the study, it was found that GGBFS can replace cement up to a percentage of 50%, with its compressive strength comparable to conventional concrete. However, the addition of GGBFS in concrete mixes slowed the development of concrete compressive strength at early age. Concrete modulus of elasticity decreases with increasing GGBFS, but not significantly. The increasing percentage of GGBFS causes the pore volume to decrease, indicating the greater durability of GGBFS based concrete compared with the conventional one.