Performance Assessment of Concrete Using Paper and Wastewater Sludge to Replace Part of the Cement

Along with deforestation and the use of fossil fuels, the cement manufacturing sector contributes significantly to carbon dioxide (CO₂) emissions. Additionally, the concrete industry is one of the major consumers of natural raw resources, which has an impact on environmental sustainability. In order to tackle these issues, this study examines the effects of partially substituting paper mill and wastewater sludge for cement in weight percentages of 5%, 10%, and 15% on the compressive, split tensile, and flexural strengths of concrete at 7 and 28 days of curing. According to experimental data, the 5% replacement mix showed better mechanical qualities than the control mix (0% replacement), suggesting that it could be a sustainable option in the manufacturing of concrete, even though higher replacement levels resulted in a decrease in strength. Strength was shown to decrease after 5%, underscoring the drawbacks of adding too much sludge. The viability of using industrial by-products in concrete to lessen reliance on cement and CO₂ emissions while preserving structural integrity is clarified by this study. By encouraging the use of waste materials in cement-based composites, the findings support the continuous efforts towards sustainable construction methods.