Optimizing mechanical and microstructural properties of concrete with steel slag aggregate using response surface methodology
Year: 2025
Type: article
Abstract: The depletion of natural river sand has intensified the need for sustainable alternatives in concrete production. This study investigates steel slag aggregate (SSA) as a fine aggregate replacement to enhance mechanical, durability, and microstructural performance . Concrete mixes containing 0%, 25%, 50%, 75%, and 100% SSA were tested at 7, 28, 56, and 90 days for compressive, split tensile, and flexural strengths. At 90 days, the 100% SSA mix achieved compressive and flexural strengths of 51.01 MPa and 5.76 MPa, representing 28% and 33% increases over the control. Durability assessments, including chloride and sulphate resistance, water absorption, and pH stability, showed minimal weight loss (0.18%) and over 92% strength retention in the 100% SSA mix under aggressive conditions. SEM revealed a denser matrix and improved interfacial transition zone, while XRD confirmed increased C–S–H formation and reduced portlandite peaks. Response surface methodology (RSM) optimization identified an optimal blend of 73.61% SSA and 14.66% natural sand, yielding a composite desirability of 1.0. These improvements are attributed to the angular morphology and latent hydraulic activity of SSA, which enhance particle packing, interlocking, and long-term hydration. The findings confirm that SSA is a technically viable and environmentally sustainable alternative to natural sand, capable of producing high-performance concrete with superior long-term strength, durability, and microstructural integrity in harsh environmental conditions.
Source: Results in Engineering
Authors: S. Azhagarsamy, N. Pannirselvam, J. Vanjinathan, R. Premkumar, Dasari Vijayakumar
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,940
OpenAlex ID: W4413451407