Sustainable Utilization of Marble Dust and Blast Furnace Slag as Fine Aggregate Replacement in Pavement Quality Concrete: A Comprehensive Review with Taguchi Optimization

The depletion of natural river sand and rising environmental burden of industrial waste disposal have intensified global interest in sustainable concrete technology. This paper reviews and presents experimental results on the partial replacement of natural fine aggregates with Marble Dust (MD) and Blast Furnace Slag (BFS) in Pavement Quality Concrete (PQC), optimized using the Taguchi Design of Experiment (DOE) with an L9 orthogonal array. Three design parameters — MD replacement (0%, 10%, 20%), BFS replacement (0%, 15%, 30%), and water-cement ratio (0.35, 0.38, 0.40) — were evaluated for M40 grade PQC as per IRC:44-2017. The optimal mix (20% MD + 30% BFS, W/C = 0.38) yielded a 28-day modulus of rupture of 5.32 MPa, exceeding the IRC:58-2015 minimum of 4.50 MPa by 18.2%. ANOVA identified water-cement ratio as the dominant factor (31.2% contribution). SEM and XRD confirmed pozzolanic mechanisms, with a 35% reduction in Portlandite and 28% increase in C-S-H formation. Results demonstrate that a 50% combined substitution of natural sand with industrial by-products is technically viable and yields superior PQC.