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Item Enhanced thermal performance of fiber-reinforced cementitious composite with high-volume fly ash and steel slag aggregates(ACS, 2025-04) Lahoti, MukundExisting cementitious composites often undergo severe degradation when exposed to high temperatures. The present study proposes utilization of high-volume fly ash (HVFA) and steel slag (SS) aggregates to address this issue. Hybrid fiber reinforcement in the form of basalt fibers and polypropylene (PP) fibers have also been utilized. A total of 120-cylinder specimens were cast for the elevated temperature testing between 200°C and 800°C, and the residual compressive and microstructural properties were analyzed. Results indicate that the HVFA mixes with 100% SS fine aggregates and hybrid length basalt fiber yield optimal performance at elevated temperatures. Specifically, the mix containing 100% SS aggregates retained 101%, 115%, 113%, and 55% of its compressive strength at 200°C, 400°C, 600°C, and 800°C, respectively. Microstructural analysis further revealed that the use of HVFA-SS system enhanced the elevated temperature performance by promoting the pozzolanic reaction of slow reacting fly ash particles, tobermorite formation, and improvement in the interfacial transition zone. Also, excellent resistance to cracking and spalling was observed. Overall, this study provides new perspective on the design of sustainable fiber-reinforced cementitious composites with excellent thermal endurance.Item Novel lime-silica fume-modified limestone calcined clay cement (LC3) binder system for sustainable pavement construction(Springer, 2025-07) Lahoti, MukundLimestone calcined clay cement (LC3) has emerged as a promising sustainable alternative to ordinary Portland cement (OPC), offering comparable mechanical properties while significantly reducing carbon emissions. Conventional LC3 cement typically consists of approximately 50% ordinary Portland cement (OPC), 30% calcined clay, 15% limestone, and 5% gypsum. In this study, we refer to the binary blend of limestone and calcined clay as LC2 for convenience. This study explores two strategies to enhance LC3’s sustainability: (i) increasing the LC2-to-binder ratio and (ii) replacing OPC entirely with a calcium oxide (lime)–silica fume blend, where silica fume acts as a pozzolan to enhance hydration and strength development (all mixes contain 5% gypsum as well). A detailed investigation of 22 mix designs is conducted to evaluate compressive strength and feasibility for pavement applications, with comparison to conventional OPC-based LC3 and OPC-fly ash mortars. Microstructural analyses, including X-ray diffraction (XRD), scanning electron microscopy (SEM)-energy dispersive X-ray spectrometry (EDS), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA), further corroborate the findings. Results indicate that a balanced CaO/silica fume ratio is crucial for achieving strength comparable to 70:30 OPC-based LC3; excessive CaO leads to detrimental expansion and mix instability. A maximum compressive strength of 27.6 MPa was observed for LCS-70 mixes (LCS-70-4.0), and a maximum of 29.2 MPa was observed for the LCS-50 mixes (LCS-50-1.8). Among the investigated mixes, LCS-70-1.0—where LCS refers to the LC2-CaO–silica fume system, 70 represents the LC2-to-binder ratio (70:30), and 1.0 denotes the CaO-to-silica fume ratio—emerges as the most optimal, offering a sustainable balance of strength, cost, and environmental impact. A total score of 4.46 is observed for this mix, which is higher than any other. The study concludes that lime-silica fume-modified LC3 is a viable alternative to both OPC and conventional LC3, making it suitable for low-volume pavement applications while significantly reducing embodied carbon and energy consumption.Item Exploratory study on concrete incorporating copper tailings and marble dust as partial substitutes for ordinary portland cement(Springer, 2025-07) Lahoti, Mukund; Srivastava, AnshumanSupplementary cementitious materials are crucial to reduce costs and carbon footprint, as traditional cement production emits greenhouse gases. This study explores using copper tailings and marble dust as substitutes for Ordinary Portland Cement (OPC) in concrete. In this investigation, three concrete mixes were designed, and tests were carried out to compare their tensile and compressive strengths. C0M0 served as the control mix, i.e., mix with no replacement of OPC. While in C5M5 mix, 10% OPC was replaced by 5% copper tailings and 5% marble dust. While in mix C5M10, 15% OPC was replaced by 5% copper tailing and 10% marble dust. Experimental observation was that the control mix (C0M0) exhibited highest compressive strength, which then declined for C5M5 mix and further retreated in increasing path in C5M10 mix, with almost reaching compressive strength of the C0M0 (control) mix. The compressive strength as compared to the control mix was reduced by about 24.8% for C5M5 mix and close to 0.9% for C5M10 mix. The observed decrease in strength was attributed to the moisture-absorbing nature of copper tailings and marble dust, which limited water availability for OPC hydration, while marble dust's filler action contributed to strength gain. Ultrasonic Pulse Velocity (UPV) tests established a relationship between compressive strength and sound velocity. Economic analysis revealed the cost-effectiveness of concrete incorporating copper tailings and marble dust. The study highlights the potential for developing concrete strength with these waste materials, promoting environmentally friendly and cost-effective construction practices.Item Computational design of fly ash geopolymer mortar using experimental and attribute evaluation approaches(Springer, 2024-10) Lahoti, Mukund; Srivastava, AnshumanGeopolymer is a ceramic-like inorganic material synthesized at room temperature and is a potential sustainable replacement of Portland cement. In the present work, a comprehensive experimental program was designed to evaluate the relative importance of mix design factors controlling the strength of fly ash geopolymer mortar. Restrained factors, namely, temperature of curing; alkaline solution to fly ash (L/FA) ratio; sodium silicate to sodium hydroxide (SS/SH) ratio; sodium hydroxide molarity; and fly ash to sand (FA/Sand) ratio, and unrestrained factors, namely, H2O/Na2O; SiO2/Al2O3; SiO2/Na2O; and Al2O3/Na2O molar ratios, were considered for evaluation. Feature subset selection and multivariate adaptive regression splines (MARS) techniques were used to determine the significance of these factors. Results show that temperature of curing is the most significant factor. FA/Sand and L/FA are found to affect compressive strength more significantly than sodium hydroxide molarity and SS/SH. Except for H2O/Na2O molar ratio, other molar ratios were observed to be very less significant. It is noted that mix design of geopolymer mortar should not be based on the molar ratios, instead mix design must be prepared by controlling the restrained factors. The findings of this study should be helpful in optimization of design factors leading to a robust geopolymer mix.Item Synergic valorization of nickel-chrome plating sludge via alkali activation of steel slag and fly ash: performance analysis(Springer, 2024-09) Lahoti, Mukund; Singhal, Anupam; Routroy, Srikanta; Bhunia, DipenduNickel–chromium plating sludge (NCPS) is a hazardous waste due to high concentration (~ 25%–30%) of chromium and nickel. Electric arc furnace slag (EAFS) is a by-product of secondary steel manufacturing through the electric arc furnace route. In this work, we valorized NCPS in an innovative ambiently cured alkali-activated NCPS-Fly ash-EAFS mortar (ANFEM). NCPS substituted the binder from 0 to 25% (by weight) in the step size of 5%. The binder composition had EAFS/fly-ash = 1.0, activator/binder = 0.45, silicate/hydroxide = 2.5. Incorporation of NCPS in ANFEM resulted in several benefits such as successful NCPS immobilization, improving the flash setting and flowability issues of alkali-activated EAFS and minimal degradation in mechanical properties. Microstructural investigation by XRD, FTIR, SEM offered insights on the underlying mechanisms of NCPS valorization and corroborated the observed results of compressive strength, water absorption, bulk density, acid resistance, and surface porosity test. At 10 wt% substitution of NCPS, ANFEM produced optimum results, such as compressive strength of 40 MPa; Wabs enhancement by 4.2%; bulk density reduction by 1.1%; and the least acid-induced deterioration. Extensive leaching tests determined leachate’s heavy metals concentration to be well-within the permissible limits. Factory scale deployment of developed methodology produced paver blocks well-satisfying Indian Standard Code 15,658: 2006.Item Optimization of sandstone processing waste, electric arc furnace slag, and fly ash-based ternary blended eco-friendly geopolymers(Springer, 2024-11) Bhunia, Dipendu; Chakraborty, Sayantan; Lahoti, MukundOver the years, ordinary Portland cement (OPC) has been used to meet growing demands of land and housing facilities arising out of population overburdens. It is well documented that OPCs, besides their outstanding qualities as building materials, are also significant contributors to global greenhouse gases (GHG). Consequently, recent years have noticed an emerging interest in the search for alternatives to Portland cement-based binders. Geopolymers are well-suited to serve this purpose owing to their superior attributes and low CO2 emissions compared to conventional cement. Still, the industrialization of geopolymers has not reached a meaningful value due to the prevailing fundamental barriers involving the requirement of corrosive environments and intensive heat-curing regimes in post-fabrication processes. The current study investigates the viability of using synergistic mixtures based on stone residues, pulverized ash, and steel slags in fabricating geopolymer composites cured at ambient temperature with reduced ingestion of alkalis. A comprehensive assessment of the engineering, mineralogical, and microstructural characteristics was performed in terms of setting times, physico-mechanical, durability, non-destructive, and analytical tests. Further, a scaled-down approach was utilized to evaluate the feasibility of the designed composites as construction entities. The incorporation of SW (10–40%) prolonged the setting periods (~ 150 min.) and abridged the engineering properties of the ternary pastes collectively by 127% due to silica coalescences. Besides, replacements of stone residues with FA (20–30%) and EAF (30–60%) improved the blend performance due to Ca and Al assimilations. All the developed composites satisfied the acclamations for OPC grade 33, CEM V class 32.5N, and OPC Type – I suggested by IS, EN, and ASTM standards, respectively, with matrices constituting CASH-CSH-NASH-(N,C)-A-S–H type gelation complexes identified by the X-ray, infrared, and electron imaging spectroscopic analysis. In addition, a cumulative deficit of about 60–90% was observed in energy and carbon footprints relative to OPCs, indicative of the binders’ sustainability traits.Item Novel LCA-centric mix design approach for alkali-activated EAF slag with hybrid optimization techniques(Springer, 2024-12) Lahoti, Mukund; Pradhan, SubhasisThis study presents an innovative life cycle assessment (LCA)-centric approach for optimizing the mix design of alkali-activated materials (AAMs) as sustainable alternatives to ordinary portland cement (OPC). The AAMs are developed using electric arc furnace slag (EAFS) and fly ash as precursors. The environmental performance is evaluated using the ReCiPe midpoint methodology, considering both mass and economic allocation methods. The results indicate that global warming potential and terrestrial ecotoxicity are the primary environmental impact categories across all mixes and allocation scenarios. A Taguchi-based hybrid optimization technique, integrating gray relational analysis (GRA) and analytical hierarchical process (AHP)-weighted GRA, is employed to determine the optimal mix design based on fresh properties, mechanical performance, durability, and sustainability indices. The AHP-GRA analysis reveals that mixes containing at least 50% EAFS perform better than OPC in terms of overall sustainability. A blend of 75% EAFS and 25% fly ash is recommended for achieving the best balance between performance and environmental impact, offering a promising alternative for sustainable construction practices.Item Comprehensive assessment of leaching characteristics in electric arc furnace slag-based alkali-activated mortar(Springer, 2025-03) Lahoti, MukundThis study investigates the leaching resistance and environmental performance of electric arc furnace slag (EAFS) as a precursor in alkali-activated materials (AAMs), contributing to sustainable construction practices and reducing reliance on conventional cement. The research employs detailed leaching analysis to evaluate the chemical stability, environmental impact, and long-term performance of EAFS-based AAMs (EFAM). Key findings reveal stable pH values in leachate samples, indicative of precursor properties and effective alkali activation, alongside increasing electrical conductivity over time due to the formation of durable ionic bonds. The release of heavy metals, such as Zn, Cu, and Cr, decreases significantly after 60 days, highlighting effective stabilization mechanisms. Distinct leaching patterns of oxyanions like arsenic and chromium, coupled with minimal leachability of elements such as molybdenum and barium, emphasize the material’s environmental safety. Additionally, calcium in the system reduces the mobility of certain elements, ensuring compliance with environmental standards. All leached metals remain below detection limits across samples, confirming the suitability of EFAM for construction applications without adverse ecological effects. This study underscores the relevance of thorough leaching analysis in validating the safety and sustainability of novel construction materials, paving the way for their broader adoption in eco-friendly construction.Item A Feasibility Study on the Potential Usage of Engineered Cementitious Composites in Indian Pavements(Springer, 2022-09) Lahoti, MukundThe global concrete consumption has been rising at over 2.8% per annum, reaching as high as 4.08 billion metric tons in FY-2021 alone. A significant chunk of this is being used in pavement construction to eventually reduce the usage of traditionally utilized asphalt and RCC in pavements and to improve environmental impact, pavement performance, and life. This study addresses the potential of using engineered cementitious composites (ECC) in comparison with traditional materials like RCC. The scope of this paper includes an in-depth analysis of material properties, economic benefit, and the lifecycle assessment of ECC, in comparison with RCC and an another alternative fiber-reinforced concrete (FRC). The framework thus established to analyze the feasibility of ECC in the Indian context is based upon the use case of FRC as discussed subsequently in the form of a case study. A similar basis has been utilized to discuss a case study on an M45 ECC mix. A similar skeleton approach can be followed to comprehend and analyze the cases of ECC usage in any alternative geography or climatic condition by choosing a mix suitable to the respective location, material availability, and logistics. It is found that ECC offers a 30% reduction in total lifecycle costs as compared to conventional concrete if a 50-year analysis period is considered.Item A Universal Metric for Robust Evaluation of Synthetic Tabular Data(IEEE, 2024-01) Lahoti, Mukund; Narang, PratikSynthetic tabular data generation becomes crucial when real data are limited, expensive to collect, or simply cannot be used due to privacy concerns. However, producing good quality synthetic data is challenging. Several probabilistic, statistical, generative adversarial networks and variational autoencoder-based approaches have been presented for synthetic tabular data generation. Once generated, evaluating the quality of the synthetic data is quite challenging. Some of the traditional metrics have been used in the literature, but there is lack of a common, robust, and single metric. This makes it difficult to properly compare the effectiveness of different synthetic tabular data generation methods. In this article, we propose a new universal metric, TabSynDex, for the robust evaluation of synthetic data. The proposed metric assesses the similarity of synthetic data with real data through different component scores, which evaluate the characteristics that are desirable for “high-quality” synthetic data. Being a single score metric and having an implicit bound, TabSynDex can also be used to observe and evaluate the training of neural network-based approaches. This would help in obtaining insights that was not possible earlier. We present several baseline models for comparative analysis of the proposed evaluation metric with existing generative models. We also give a comparative analysis between TabSynDex and existing synthetic tabular data evaluation metrics. This shows the effectiveness and universality of our metric over the existing metrics.