Integrated mechanical and environmental assessment of concrete with EAF slag coarse aggregate

This study investigates the mechanical and environmental performance of concrete incorporating locally sourced electric arc furnace (EAF) slag aggregate as a partial volumetric replacement for natural coarse aggregate in Kuwait. Nominal replacement levels of 25%, 50% and 75% were compared with a plain reference and two independent fiber benchmarks containing recycled tire steel fibers or polypropylene microfibers. Fresh workability, hardened density, water absorption, compressive strength, splitting tensile strength and cradle-to-gate impacts were evaluated. Two specimens were tested for each mixture and age in compression and splitting. At 28 days, 75Slag had the highest recorded mean cube strength, 46.64 MPa, compared with 31.05 MPa for Ref, a numerical increase of 50.2%. This response was accompanied by a 14.8% higher density and a slump decrease from 220 to 90 mm. The single recorded absorption values were 4.544% and 5.912%, respectively; their mass-based difference does not directly establish a change in pore volume. Under the adopted allocation and supply assumptions, 75Slag reduced modeled climate change, the non-renewable energy resource indicator and the abiotic material resource depletion indicator by 17.8%, 26.5% and 29.8%. The corresponding strength-normalized reductions were 45.3%, 51.0% and 53.3%. These results identify 75Slag as a promising case within the tested series, with further verification needed for source-specific stability and environmental performance.