Engineering optimization of ternary waste‐ash blends for sustainable cementitious materials using ANOVA and response surface method

Abstract

The rapid accumulation of household waste and the environmental impacts of Portland cement production highlight the need for sustainable strategies that promote waste valorization and reduce cement consumption. This study investigates chicken bone ash (ChBA), cow bone ash (CBA), and wood waste ash (WWA) as partial Portland cement replacements in mortar. The ashes were incorporated at 0%, 2.5%, 5%, 7.5%, and 10%, while curing age ranged from 2 to 56 days. Compressive strength, flexural strength, and dynamic modulus of elasticity were evaluated experimentally. Response surface methodology (RSM) and analysis of variance (ANOVA) were employed to develop predictive models, assess factor effects and interactions, and optimize ternary ash formulations. The models demonstrated satisfactory predictive performance, with R ² values of 0.95, 0.82, and 0.96 for compressive strength, flexural strength, and dynamic modulus of elasticity, respectively, while differences between predicted and adjusted R ² values remained below 0.20. Results showed that combinations of ChBA, CBA, and WWA can enhance long‐term mechanical performance while reducing cement content. Statistical optimization identified suitable ternary formulations that balance cement reduction and mechanical performance. The study demonstrates an integrated experimental–statistical approach for simultaneously valorizing household waste ashes and developing more sustainable cement‐based materials within a circular‐economy framework.