Performance and Microstructural Evaluation of High Clinker Replacement with Marble Dust and Calcined Clay in Ternary Binders

Abstract

The cement industry is one of the major sources of global CO ₂ emissions, creating an urgent need for sustainable alternatives to conventional Portland cement. This study investigates the feasibility of high‐volume clinker replacement using calcined clay and marble dust, an industrial byproduct generated during marble processing, as supplementary cementitious materials (SCMs). Ternary binder systems containing only 35% clinker were developed with the remaining fraction replaced by a 1:2 ratio (by weight) of marble dust to calcined clay at a constant water‐to‐binder ratio of 0.4. Mechanical performance was evaluated through compressive strength testing at 3, 10, and 28 days, while microstructural evolution was assessed using mercury intrusion porosimetry (MIP). The results demonstrated continuous strength development, with compressive strengths of 19.1 MPa, 38.1 MPa, and 46.8 MPa achieved after 3, 10, and 28 days, respectively. Despite the high clinker replacement level, the developed binder system attained compressive strengths exceeding 40 MPa at 28 days, indicating satisfactory mechanical performance. MIP analysis further revealed progressive pore refinement and reduction in total porosity with hydration time, confirming the development of a denser and more stable microstructure. The findings highlight the strong potential of utilizing industrial waste materials such as marble dust in high‐volume clinker replacement systems for the production of sustainable, low‐carbon, and mechanically competent cementitious materials.