PSI - Issue 70

Siddesh K N et al. / Procedia Structural Integrity 70 (2025) 231–238

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1. Introduction Concrete is the most widely used construction material, and the increasing demand for cement contributes significantly to CO₂ emissions and environmental degradation. As a result, several studies have explored the incorporation of industrial waste materials in concrete ways to promote sustainability and cost-effectiveness. Among these, aluminum dross — a hazardous by-product generated during aluminum smelting — has drawn attention for its potential application as a partial replacement for cement. Aluminum dross is composed primarily of aluminum oxide, with smaller amounts of metallic aluminum and other oxides, which can exhibit pozzolanic or filler characteristics under certain conditions. Several researchers have explored its incorporation in cementitious materials with varied results. Al-Mutairi and Haque (1997) investigated the use of aluminum dross in concrete and reported that a replacement level up to 10% showed a positive influence on compressive strength. Similarly, Elinwa and Mahmood (2002) explored ash-based waste materials and emphasized the importance of proper fineness and chemical composition in determining their suitability in cement replacement applications. According to Pappu et al. (2007), the integration of industrial waste into concrete not only reduces environmental burdens but also enhances the performance of concrete when optimized properly. However, the mechanical properties and durability parameters can vary significantly depending on the source, particle size, and processing of aluminum dross. Studies such as those by Rajan et al. (2016) demonstrated that high replacement levels beyond 15% may lead to a decline in strength due to reduced cementitious content and increased porosity. Despite these advancements, a gap remains in understanding the full mechanical behavior of aluminum dross concrete across different replacement levels and curing ages. Moreover, limited literature exists on the behavior of concrete incorporating locally available aluminum dross, especially in the context of strength performance and sustainability evaluation. Therefore, this study aims to systematically assess the influence of varying aluminum dross replacement levels (0% to 30%) on the compressive, split tensile, and flexural strengths of concrete, ultimately identifying an optimum dosage suitable for structural applications. 1.1. Materials and Methodology The materials used for concrete in beams and cubes include coarse aggregates, fine aggregates (M sand), cement, plasticizers, steel reinforcement, and aluminum dross. Aggregates provide bulk and enhance mechanical properties, with 20 mm coarse aggregates having a specific gravity of 2.65 and M sand (Zone III) at 2.54. Ordinary Portland Cement (OPC), the binding agent, has a specific gravity of 3.10. Plasticizers (Conplast SP 430) improve workability, with a specific gravity of 1.20. Steel reinforcement consists of 12 mm diameter rebars and 8 mm diameter stirrups. Aluminum dross, a by-product of aluminum smelting, enhances shear performance, with a specific gravity of 2.92.

Fig.1. Aluminum Dross and Conplast SP 430 in casting cubes and beams