Expanded Clay Aggregate Incorporation in Self-Compacting Concrete through Multi-Performance Evaluation of Fresh, Mechanical and Durability Characteristics

¹ Research Scholar, Jawaharlal Nehru Technological University, Department of Civil Engineering, Ananthapuram, AP, India
² Professor, Jawaharlal Nehru Technological University, Department of Civil Engineering, Ananthapuram, AP, India.
³ Professor, Annamacharya Institute of Technology and Sciences, Department of Civil Engineering, Tirupati, AP, India

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 3 August 2026

Abstract

This study evaluates the feasibility of using expanded clay aggregate (EC) as a sustainable coarse aggregate replacement in self-compacting concrete (SCC). Six SCC mixtures with 0–100% EC replacement were prepared while maintaining a constant binder composition and water-to-binder ratio. Fresh properties were assessed using EFNARC (2005) tests, whereas compressive, split tensile, flexural, and durability properties were evaluated at 7, 28, and 90 days. All mixtures satisfied the EFNARC requirements for workability. The optimum performance was obtained at 20% EC replacement (A1B6), which achieved the highest slump flow (620 mm), compressive strengths of 27.08, 42.46, and 45.75 MPa, split tensile strengths of 3.93, 4.92, and 5.11 MPa, and flexural strengths of 4.45, 5.57, and 5.78 MPa at 7, 28, and 90 days, respectively. The same mixture also exhibited superior resistance to acid and sulphate attack. The improved performance is attributed to the internal curing effect of porous EC particles, while higher replacement levels reduced strength because of increased porosity and lower aggregate stiffness. Overall, 20% EC replacement provides the optimum balance between workability, mechanical performance, and durability for sustainable structural SCC.