Optimization of Multi-Component Cement Mortar Using a Taguchi Orthogonal Array Design

Developing low-carbon cement-based materials is a critical strategy for reducing the carbon footprint of the construction sector. This study optimized multi-component cement mortars incorporating natural zeolite (NZ), fly ash (FA), blast furnace slag (BFS), and calcium hydroxide (CH) using an L9 Taguchi orthogonal array and range analysis. Mechanical and physical properties, microstructural characteristics, statistical modeling and environmental impact were evaluated. The optimized mixture, OPT1 (10% NZ, 10% FA, 40% BFS, and 2% CH), achieved compressive strengths of 34.97 MPa and 62.67 MPa at 7 and 28 days, respectively, exceeding the control mortar by 8.4% at 28 days. The results indicated that supplementary cementitious materials (SCMs) reduced early-age strength due to the dilution effect; however, their pozzolanic and latent hydraulic reactions enhanced later-age strength development. OPT1 also demonstrated improved mechanical efficiency, reduced Global Warming Potential (GWP) by 35%, and achieved an eco-efficiency index (EEI) value of 124.6, which was 1.6 times that of the control mixture. These findings highlight the potential of the proposed system for high-performance and eco-efficient low-carbon cement mortars.