PERFORMANCE OF STEEL SLAG AGGREGATE CONCRETE WITH VARIED WATER- CEMENT RATIO

Abstract

Several thousands of tons of electric arc furnace slag (EAF) slag generated in Nigeria are yet to be utilised for construction; perhaps as a result of inadequate technical details for its use. The present study has evaluated the effects of varying water-cement ratio on workability and strength of locally generated steel slag aggregate (SSA) concrete. Tested samples include 150 mm concrete cubes and cylinder samples with 150 mm diameter and 300 mm height respectively. SSA was substituted in increments of 20% by weight of granite until 100% mix, while w/c was varied at 0.5, 0.55 and 0.6. Workability of fresh concrete was evaluated through slump test. Hardened concrete cubes and cylinders were subjected to compression and split tensile tests respectively, after 7, 14 and 28 days curing periods. Slump values obtained were in the range of 50 – 90 mm for all the mixes, which represented a S2 slump. Compressive strength and tensile strength increased with age and increasing slag substitution. A strength of 25 MPa for normal weight concrete was achieved at 28 days with 20% SSA substitution, only within 0.5 and 0.55 w/c ratio. However, result obtained for concrete mixes with 60% SSA and above at 28 days established that these mixes are good for production of high strength concrete.