Durability performance of low-carbon concrete incorporating optimized ratio of multiple waste materials (glass powder, biomass fly ash, and shredded rubber)
Mehran Aziminezhad, Ahmed Bediwy, Eltayeb Mohamedelhassan
Abstract
Incorporating waste materials in concrete can enhance sustainability and contribute to more environmentally friendly construction practices. However, using these materials in concrete presents challenges related to durability, mechanical, and environmental performance. This study explores the effects of incorporating glass powder (GP), biomass fly ash (BFA), and shredded rubber (SR) as partial replacements for cement and aggregates in concrete. The focus is on assessing their impact on durability, mechanical properties, and the environment. To determine the most effective combination of waste materials, Response Surface Methodology (RSM) is employed to design the experimental program and optimize the mixture proportions. The research evaluates air content, freeze-thaw resistance, compressive strength, Young’s modulus of elasticity, splitting tensile strength, modulus of rupture, surface electrical resistivity, life cycle assessment (LCA), rapid chloride penetration test, and global warming potential of concrete mixtures. Results show that replacing cement with 20% GP improves durability and strength, raising electrical resistivity by 240% and achieving durability factors of more than 90%. However, SR above 7.5% reduces freeze-thaw resistance and stiffness. In addition, optimal mixes with a maximum of 16% GP or 15% BFA reach a compressive strength of 30 MPa and limit GWP to 297 kg CO₂-eq/m³.