Modified particle packing approach for optimizing waste marble powder as a cement substitute in high-performance concrete

Abstract

This study explores the potential of utilizing waste marble powder (WMP) instead of cement to develop environmentally friendly high-performance concrete (Eco-HPC). It assesses Eco-HPC's particle packing density, workability, mechanical characteristics, and durability at various stages. High-performance concrete (HPC) mixtures were optimized using a Modified Andreasen and Andersen (MAA) particle packing model to minimize cement content from 550 to 385 kg/m3. The MAA particle packing model demonstrated its ability to enhance and refine mixture microstructures. Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) were employed to optimize and predict the mechanical properties and water absorption of modified Eco-HPC blends at 7, 28, and 56 days. As the coefficient of determination indicates, ANN outperformed RSM in predicting Eco-HPC properties across various ages. Substituting cement with WMP, Silica Fume (SF), and Fly Ash (FA) results in a dense microstructure. The mortar containing 20 % WMP and 10 % SF achieves the highest wet packing density at 0.9749 and the lowest void ratio at 0.025, respectively. The formation of CSH in the 70C/20 M−10SF mixture led to a substantial reduction in calcium hydroxide content, indicating enhanced mechanical properties. SEM analysis at 56 days demonstrated significant pozzolanic reactions in the 70C/20 M−10SF mixture, resulting in substantial CSH formation. Furthermore, the embodied CO2 index for 70C/20 M−10SF was reduced to 5.07 kg/MPa/m3, compared to the 100C/0M with value of 8.17 kg/MPa/m3. Economic and environmental assessments reveal enhanced mechanical properties and microstructure when using WMP. This evaluation confirms the effectiveness of 70C/20 M−10SF utilization, paving the way for further advancements in Eco-HPC development.