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Item Carbon sequestration and life cycle assessment of an industrial waste-derived carbon sink binder under saline water utilization(Taylor and Francis Ltd., 2025) M, N.; Palanisamy, T.The development of low-carbon construction materials is essential to meeting global climate targets. This study presents a carbon-negative binder synthesized primarily from iron-rich industrial byproducts (mill scale), supplemented with fly ash, metakaolin, and limestone. Oxalic acid enhances iron dissolution and promotes stable carbonate formation during CO2 curing. Strength development occurs through direct CO2 mineralization, with carbonation curing conducted at 0, 1.5, and 3 bar using both normal and saline water. Specimens cured at 3 bar with saline water achieved compressive strengths exceeding 60 MPa and carbon sequestration rates up to 1.03% per day. Carbonation depth followed a square-root time relationship, with enhanced propagation under high-pressure saline conditions. Microstructural analyses (XRD, TGA–DTG, FTIR, FESEM) confirmed the formation of siderite, lepidocrocite, nesquehonite, and calcite within a dense matrix. Life Cycle Assessment indicated approximately 85% lower fossil-based global warming potential and over 80% reductions in water consumption compared to Ordinary Portland Cement, demonstrating a potable-water-free, resource-efficient binder suitable for circular and climate-resilient infrastructure. © 2025 Informa UK Limited, trading as Taylor & Francis Group.Item Oxalic acid optimization for iron-based solid waste conversion into a carbon-sequestering composite building material(Elsevier B.V., 2025) M, N.; Palanisamy, T.The cement industry significantly contributes to global CO2 emissions, accounting for approximately 164 million metric tonnes annually, while total emissions from all sources reach 37 billion metric tonnes. Concurrently, the iron and steel sector generates substantial waste, producing about 500 kg of waste per tonne of steel. Addressing these environmental challenges is crucial for sustainable development. This study presents a sustainable alternative to traditional cement by developing a novel binder material composed primarily of waste iron. The alternative binder not only avoids CO2 emissions but also absorbs CO2 during carbonation curing, effectively contributing to carbon sequestration. Key parameters, including particle size, oxalic acid dosage, and water-to-binder ratio, were individually tested and analyzed for their impact on compressive strength, leading to the finalization of a 75?m particle size and a 0.2 water-to-binder ratio, which yielded compressive strengths of up to 45 MPa. The wet mix method for oxalic acid incorporation demonstrated superior performance compared to the dry mix approach. Comprehensive analyses, including XRD, FTIR, TGA/DTG, and FESEM, confirmed the enhanced reactivity and performance of the material with finer particles and optimized oxalic acid dosage. By utilizing 80% of waste materials, this alternative binder addresses both waste management and carbon capture, aligning with global sustainability objectives and advancing the development of eco-friendly building materials. © 2024 Elsevier B.V.Item Coconut shell biochar–Bacillus cereus DKBovi-5 based biocomposite as a sustainable additive for cement mortar: Effect of pyrolysis temperature on characterization, strength, hydration, and healing(Elsevier B.V., 2025) Anoop, P.P.; Palanisamy, T.Although biochar–bacteria composites have been explored for self-healing in cementitious materials, the influence of pyrolysis temperature on microbial compatibility and healing performance has been insufficiently investigated. This study addresses this gap by examining how pyrolysis temperature affects the physicochemical properties of coconut shell biochar and its effectiveness as a microbial carrier in mortar. Biochar produced at 300 °C, 400 °C, and 500 °C was characterized, and Bacillus cereus DKBovi-5 was immobilized onto it to form biocomposites. The biocomposites were incorporated into mortar to evaluate mechanical, microstructural, and crack healing performances. Characterization of biochar showed enhanced crystallinity at 500 °C as indicated by XRD, development of primary and secondary pores confirmed by FESEM, and increased micronutrient concentrations due to thermal enrichment observed through ICP-MS. Compressive strength restoration increased from 80.21 % to 91.23 % between 300 °C and 500 °C temperatures. TGA analysis, interpreted using Bhatty's method, indicated an increase in the degree of hydration from 61.65 % to 65.33 %. Rietveld refinement of XRD data revealed a rise in calcite content from 24 % to 51 %. FESEM imaging confirmed the deposition of hydration products within the biochar pores. Healing evaluation showed closure of cracks up to 0.762 mm and 0.920 mm in mortars with 300 °C and 500 °C biocomposites, respectively, corresponding to healed areas of 92.49 % and 100 %. The healed products in all biocomposites were confirmed as calcite through FESEM-EDS and XRD analyses. Optimized pyrolysis at 500 °C yielded a biocomposite with superior microbial healing performance, establishing its suitability as a self-healing admixture in bio-mortar applications. © 2025 Elsevier B.V.Item Exploring pore solution chemistry and solid phase assemblies in cement-based electrolytes for potential structural batteries(Elsevier B.V., 2025) Sundaramoorthi, S.; Palanisamy, T.This study develops a sustainable cement-based electrolyte for a cement-based battery by incorporating supplementary cementitious materials (SCMs) and epsom salt to enhance electrical performance. Ionic composition and liquid-phase characterization revealed that SCM and epsomite reduced [Ca2+] and [OH?] ion concentration while modulating [SO42?] concentration in the pore solution, depending on the SCM type. Silica fume-based mixes, with lower reactive alumina content, showed increased [SO42?] and higher ionic strength. The SF5E mix exhibited superior electrical performance, achieving a 56 % higher discharge life. Cyclic voltammetry indicated quasi-reversible behaviour with hybrid capacitive-faradaic characteristics, confirming its suitability for energy storage. The microstructural analysis highlighted the stable C–S–H formation, ensuring mechanical integrity alongside electrical functionality. The findings establish SF5E as the optimal electrolyte, demonstrating a balance between ionic conductivity and structural stability. By linking cement chemistry with battery performance, this work lays the foundation for a scalable, self-sustaining energy storage system for applications in structural health monitoring. © 2025 Elsevier B.V.