Experimental investigation on strength, durability and micro structural characteristics of slag based concrete

Abstract

In this study, experimental investigations are conducted using 100 percent Portland Slag Cement and Processed Granulated Blast Furnace Slag sand (PGBFS, iron slag) with 100 percent and partial or full replacement of Natural Coarse Aggregates (NCA) with Ladle Slag Aggregates (LSA) with 0, 20, 40, 60, 80, and 100 percent variations. All of the materials used in the inquiry are manufactured by Jindal Steel Works' Bellary factory in India. It has been shown that aggregates containing 20 percent Ladle slag provide the highest strength. Again, 5 percent variation strength tests are conducted, and it is determined that maximum strength is attained with 20 percent variance. The XRD examination demonstrates that the intermolecular bonding between hardened aggregate and cementitious paste is mostly comprised of silicates with a high degree of crystalline order. Due to the fact that the XRD test pattern is mostly composed of quartz aligned with alite and belite, the spaces between the substrate have been minimized to a minimal extent, which may contribute to the concrete's excellent endurance. For 20 percent variance, the tests of durability are modest, as shown by the durability test. The SEM images show porous structures which suggest a limited formation of C-S-H, gel and a correlation between them. The calcium hydroxide generated during cement hydration could be the result of interaction with the reactive amorphous silica present in slag and cement, leading to the formation of C-S-H gel, which plays a role in enhancing the mechanical and durability properties of concrete.