Development and Mechanical Evaluation of Self-Compacting Concrete with Partial Replacement of Using Alccofine and Stone Dust

Self-compacting concrete (SCC) represents a significant advancement in concrete technology, offering superior workability, reduced labor requirements, and enhanced structural integrity without the need for mechanical compaction. However, the conventional production of SCC requires a high volume of cement and natural fine aggregates, which raises economic and environmental concerns due to high CO2 emissions and the depletion of natural resources. In an effort to produce a more sustainable and cost-effective SCC, this study investigates the incorporation of Alccofine, a highly reactive ultrafine slag-based material, as a partial replacement for cement, and stone dust, a by-product of aggregate crushing, as a partial replacement for fine aggregate. An M25 grade SCC was developed using varying replacement levels of Alccofine (10 to 30%) and stone dust (20 to 60%). A total of six mixes, including a control mix, were prepared and tested. Fresh properties were evaluated using EFNARC guidelines, including slump flow, V-funnel, and L-box tests to assess flowability and passing ability. Hardened properties such as compressive strength, split tensile strength, and flexural strength were determined at 7, 28, and 56 days of curing. The results indicated that a mix with 15% Alccofine and 30% stone dust exhibited optimal performance, showing significant improvement in both strength and workability compared to the control mix. Beyond these replacement levels, the performance gradually declined, likely due to excessive fines affecting the mix stability and hydration process. This study concludes that the combined use of Alccofine and stone dust in SCC not only enhances its mechanical properties and durability but also contributes to sustainable construction by reducing the reliance on Portland cement and natural sand. These findings support the feasibility of using industrial by-products in SCC production to meet both structural and environmental demands.