INTERNATIONAL JOURNAL FOR INNOVATIVE RESEARCH IN MULTIDISCIPLINARY FIELD

Abstract: The increasing demand for natural aggregates and the need for sustainable construction practices have led to the exploration of alternative materials in concrete. This study investigates the use of Linz–Donawitz (LD) slag, a by-product of the steel industry, as a partial replacement for coarse aggregate in concrete. The primary objective is to evaluate the mechanical and durability properties of concrete incorporating LD slag. The results indicated that the strength properties of concrete improved significantly with the inclusion of LD slag up to 40% replacement. The maximum compressive strength of 39 MPa was achieved at 40% replacement

Concrete mixes of M25 grade were prepared by replacing natural coarse aggregate with LD slag at different proportions of 0%, 20%, 30%, 40%, and 50%. The experimental program included tests on compressive strength, split tensile strength, flexural strength, density, and durability under acid attack using hydrochloric acid (HCl) and sulfuric acid (H₂SO₄) solutions. The percentage weight loss and strength reduction were lower in LD slag mixes compared to the control mix. The improvement in resistance was approximately 50–55% for HCl and 35–40% for H₂SO₄ at 40% replacement, demonstrating enhanced durability under aggressive conditions.

The optimum replacement level is found to be 40%, which provides the best balance of strength and durability. The use of LD slag not only improves concrete performance but also contributes to waste utilization and environmental sustainability.