Experimental Investigation on the Effect of Rice Husk Ash and Waste Paper Sludge Ash as Cement Substitutes in M20 Concrete

In the modern era of rapid industrialization and urbanization, concrete and cement mortar remain indispensable materials in construction, driven by the rising demand for housing and infrastructure. However, this growth has created major environmental challenges due to excessive use of natural resources and the large volume of industrial waste generated. If not managed properly, these wastes pose disposal issues and ecological risks. As a result, researchers are actively exploring sustainable alternatives that not only reduce dependence on cement but also improve the mechanical and durability characteristics of concrete. One of the most critical concerns in cement production is carbon dioxide CO2 emission. Nearly one ton of CO2 is released for every ton of cement manufactured, contributing significantly to climate change and environmental degradation. To address this, industrial byproducts are being investigated as partial cement replacements, which reduce CO2 emissions, conserve natural resources, and encourage circular economy practices. This research focuses on the use of Rice Husk Ash RHA and Waste Paper Sludge Ash WPSA as supplementary cementitious materials. Both byproducts possess pozzolanic properties that enhance the binding and strength characteristics of concrete. In this study, RHA and WPSA were incorporated at 2 , 4 , 8 , and 10 replacement levels by weight of cement. A total of 78 specimens, including cubes and cylinders, were prepared, cured, and tested for compressive, flexural, tensile, and consistency properties.Results showed that moderate replacement levels enhanced concrete performance, offering dual benefits of waste utilization and improved strength. Thus, incorporating RHA and WPSA represents a sustainable, eco friendly approach to green construction. Musharaf Farooq | Er. Ajay Vikram "Experimental Investigation on the Effect of Rice Husk Ash and Waste Paper Sludge Ash as Cement Substitutes in M20 Concrete" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-9 | Issue-5 , October 2025, URL: https://www.ijtsrd.com/papers/ijtsrd97542.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/97542/experimental-investigation-on-the-effect-of-rice-husk-ash-and-waste-paper-sludge-ash-as-cement-substitutes-in-m20-concrete/musharaf-farooq