Waste paper sludge ash as a pozzolanic material: Enhancing concrete performance and sustainability

Concrete, a highly versatile and widely utilized material in the global construction industry, owes its adaptability to its composition. However, the production process, primarily reliant on cement as the key binder, poses significant environmental and economic challenges. The cement industry stands as a major emitter of carbon dioxide, contributing to approximately 7% of the world’s carbon dioxide emissions, with cement itself constituting about 12% of standard concrete. To address this issue, researchers have explored alternatives to conventional disposal methods such as land filling, with a focus on incorporating waste paper sludge ash (WPSA) into concrete formulations. The study delves into the chemical composition of WPSA and its potential as a partial replacement for cement variables were 0, 5, 10, 15 and 20% by weight of cement for M25 concrete mix. Assessment of its impact on both fresh and hardened concrete properties reveals promising results. Notably, WPSA exhibits characteristics suitable for pozzolanic material, effectively altering setting times and enhancing normal consistency when blended with cement paste. Through extensive testing encompassing workability, mechanical characteristics, durability and cost feasibility of sustainability analysis of WPSA blends a concrete improving the properties of concrete and microscopic examination, notably using scanning electron microscopy, elucidates the formation of calcium silicate hydrate crucial for optimal bonding in concrete. Furthermore, X-ray diffraction analysis illustrates the crystalline structure of WPSA within the concrete matrix. Findings indicate an optimal inclusion level of 10% WPSA, demonstrating reduced environmental impact and offering insights into waste reduction strategies.