A Green Approach to Cement Reduction: Utilizing Waste Paper Sludge and Wood Ash in Concrete

The main goal of this investigation aims to establish sustainable construction practices through a study of WPS (WPS) and wood ash (WA) as cement reductions in concrete production to decrease environmental effects in cement manufacturing and industrial waste management. Cement production is a significant contributor to carbon emissions, while waste paper slurry and wood ash, by-products of the paper and biomass industries, are frequently disposed of in landfills, resulting in environmental hazards. Not only does the incorporation of these refuse materials into concrete reduce cement consumption, but it also enables the efficient management of waste. The study was an experimental investigation that aimed to determine the optimal reduction levels of WPS and WA for the purpose of attaining desirable concrete properties. Following extensive trials and performance evaluations, a variety of concrete mixtures were created by substituting cement with 10% wood ash and 5% paper slurry. The standard testing procedures were employed to assess the concrete's fresh and hardened properties, which included “workability, compressive strength, split tensile strength, flexural strength, and durability”. The results suggested that the optimal equilibrium between mechanical performance, workability, and long-term durability was attained by the combination of 10% wood ash and 5% paper slurry. The concrete workability changed when wood ash was incorporated. The ash's increased surface area and water absorption characteristics resulted in reduced flow ability at higher replacement levels. Nevertheless, this obstacle was successfully resolved by incorporating superplasticizers to preserve the desired workability. The tensile and flexural strength of concrete increased through the fibrous quality of paper residue which both limited crack propagation and strengthened concrete matrix binding. The “pozzolanic properties” of wood ash resulted in enhanced durability because they promoted the formation of an additional “calcium-silicate-hydrate (C-S-H)” gel which improved long-term strength development. The pore structure became more refined while the matrix density increased because of the “C-S-H” gel formation. “The study emphasizes the economic and environmental benefits of utilizing WPS and WA in concrete production, in addition to their technical capabilities. The partial replacement of cement with these waste materials substantially reduces material costs and reduces the carbon footprint of concrete manufacturing. This sustainable approach adheres to the circular economy principles by converting industrial refuse into valuable construction resources, thereby conserving natural resources”. Although the results indicate that WPS and WA are viable alternatives to cement, additional research is necessary to assess the concrete's long-term durability in a variety of environmental conditions. In real-world applications, (LCA) and field demonstrations can offer more profound insights into the environmental impact, economic feasibility, and structural performance of the proposed concrete mix. Using wood ash combined with paper slurry at 10% and 5% levels serves as an affordable and sustainable method to substitute cement in concrete production. The combination of wood ash with paper slurry as partial cement replacement leads to better concrete performance while supporting sustainable waste management practices. The research demonstrates the benefits of using industrial waste materials in construction products because they help achieve sustainable development goals and climate protection objectives.