Corrosion and volume stability of the blended SCC mixes containing induction furnace steel slag and crushed stone as coarse aggregate

Utilizing slag for concrete production has potential environmental benefits and ensures the sustainability of conventional concrete materials. However, in some cases, the use of slag aggregates affects the transport properties of the concrete. Therefore, it is essential to assess the durability of concrete containing slag aggregates. This study focused on assessing the corrosion resistance of ternary blended (silica fume (SF) + ground granulated blast furnace slag (GGBS)) self-consolidating concrete (SCC) mixes produced with induction furnace steel slag (IFSS) and crushed stone (CS) as coarse aggregates. To assess their durability characteristics, the following experiments were performed: accelerated aging test, 15-volt impressed voltage test (IVT), and alkali-aggregate reaction test. From the test results, it was observed that the SCC mixes produced with IFSS coarse aggregate possessed a slightly higher corrosion risk than similar mixes produced with CS coarse aggregate. The porous microstructure and existence of iron-rich mineral phases in the IFSS diminished the corrosion resistance of the IFSS group SCC mixes. Regardless of the type of coarse aggregate, blending the cement with SF and GGBS densified the microstructure and improved the corrosion resistance of SCC mixes. The maximum corrosion resistance was observed in the blended mixes with 10% silica fume and 30–60% GGBS as partial binders. In the case of accelerated ageing and alkali-aggregate reaction tests, it was found that the IFSS aggregate is innocuous and does not cause any deleterious expansion, flakes, or cracks when used in concrete.