Browsing by Author "Bhunia, Dipendu"

Now showing 1 - 20 of 40

Alkali-Activation Potential of Sandstone Wastes with Electric Arc Furnace Slag as Co-additive
(Springer, 2023-12) Bhunia, Dipendu; Chakraborty, Sayantan
Electric arc furnace slag (EAF) and sandstone waste (SW) are two of the most abundantly generated industrial wastes whose utilization as precursors and supplementary cementitious materials has not been exhaustively studied. The current research study comprehensively investigates the effects of incorporating varying proportions (0–90%) of re-melted EAF as a co-additive on the engineering properties of elevated (80 °C) and ambient (30 °C) cured alkali-activated SW-based binders. Extensive laboratory tests were conducted to assess the physio-mechanical and durability performance of the resulting alkali-activated materials (AAM). Detailed mineralogical and microstructural characterization of SW, EAF, and alkali-activated samples was carried out using sophisticated analytical techniques. Results advocated that irrespective of the curing temperatures, SW-based AAM showed improved setting behavior, compressive strength, water absorption, and porosity characteristics with the increment of EAF at all substitution levels due to the concomitant development of CASH-CSH-NASH gel phases. Overall, it can be inferred that EAFs as a pozzolanic material successfully augmented the properties of SW-based alkali-activated binders, providing an efficient solution for disposal and negative environmental impacts associated with industrial wastes.
Alkali-activation potential of stone wastes
(Elsevier, 2023-03) Bhunia, Dipendu
The industrial processing of dimensional stones generates a significant amount of waste. According to the data released in 2020 by the nations with active dimensional stone industries, it is estimated that out of 316 million tons of dimensional stones extracted each year, 161.5 million tons end up as mining or quarry waste. These are dumped in open locations creating noxious conditions for mine workers, residents of nearby communities, and the environment. In the current work, an effort has been made to manufacture alkali-activated materials (AAM) using sandstone waste (SW) and marble stone waste (MW) obtained from Rajasthan (India). The primary precursor is SW, whereas MW is partially substituted as an admixture. The elemental composition of stone wastes was determined using X-ray fluorescence spectroscopy (XRF). Stone waste-based geopolymer composite was prepared using alkaline activating solutions sodium hydroxide (NH, NaOH) and sodium silicate (NS, Na2SiO3) and tested for mechanical and physical properties. Characterization and microstructural analysis of geopolymer composite was performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) fitted with energy dispersive X-ray spectroscopy (EDS). The findings suggest that the developed geopolymer composite can be employed as a construction material that will improve the re-utilization of stone wastes, offering a workable solution to the challenges associated with their disposal.
Analytical and Experimental Investigations on Using Waste Marble Powder in Concrete
(ASCE, 2019-04) Srivastava, Anshuman; Bhunia, Dipendu
Research using marble powder as a partial replacement of cement in concrete has gained a lot of attention recently. In this paper,the effect of dried marble powder on particle packing of concrete has been demonstrated. Experimental investigations have been conducted onthe effect of marble powder on hydration reaction, strength activity index, and possible reasons for the gain in strength. In addition, statisticalmethods were used to develop two mathematical models for marble powder incorporated in concrete using experimental values. In the firstmodel, the ratios of 28-day compressive strength between concrete with cement partially replaced by marble powder and control concretehave been related to marble powder replacement percentage. In the second model proposed, modified and simplified relationships for thewater-cement law when cement is partially replaced by marble powder have been provided. The first model was validated for both standardcubes and cylinders used for testing by researchers and the predictions showed only 7.15% error as compared with the experimental values.The second model might serve as a useful tool for mix proportioning of concrete mixes incorporating marble powder in concrete. Finally,based on a review of the literature and experimental results, a set of guidelines has been proposed for the use of marble powder as a partialreplacement of cement in concrete
Assessment of carbonation depth under natural and accelerated carbonation conditions
(Indian Concrete Journal, 2016) Bhunia, Dipendu
This paper deals with the effect of accelerated carbonation on mechanical properties and durability of unreinforced concrete. Concrete with water binder ratios of 0.35, 0.50 and 0.65 were cast and kept in accelerated carbonation chamber under controlled conditions for a period of 1 year. Specimens were removed at predefined time intervals and tested for compressive strength, flexural strength, modulus of elasticity, volume of permeable pores and depth of carbonation. The depth of carbonation obtained from the accelerated carbonation conditions are used to predict the carbonation depths under natural concentration of carbon dioxide using Fick’s law and the values are compared to those obtained from a structure 60 years old
Assessment of carbonation depth under natural and accelerated carbonation conditions
(ICJ, 2016) Singh, Shamsher Bahadur; Bhunia, Dipendu
This paper deals with the effect of accelerated carbonation on mechanical properties and durability of unreinforced concrete. Concrete with water binder ratios of 0.35, 0.50 and 0.65 were cast and kept in accelerated carbonation chamber under controlled conditions for a period of 1 year. Specimens were removed at predefined time intervals and tested for compressive strength, flexural strength, modulus of elasticity, volume of permeable pores and depth of carbonation. The depth of carbonation obtained from the accelerated carbonation conditions are used to predict the carbonation depths under natural concentration of carbon dioxide using Fick’s law and the values are compared to those obtained from a structure 60 years old.
Comparative study of accelerated carbonation of plain cement and fly-ash concrete
(Elsiever, 2017-03) Singh, Shamsher Bahadur; Bhunia, Dipendu
Accelerated carbonation of plain cement concrete and concrete with fly-ash replacing cement partially, is discussed in the present paper. Mechanical properties such as compressive strength, flexural strength, modulus of elasticity, durability aspects such as depth of carbonation and porosity of carbonated concrete are studied. To study the influence of water binder ratio on the above-mentioned properties, water-binder ratios of 0.35, 0.50 and 0.65 are used. It is observed that the mechanical properties of carbonated concrete have increased with the duration of carbon dioxide exposure. So did the depth of carbonation, whereas the volume of permeable voids has reduced leading to the decrease in porosity. An expression to predict the depth of carbonation of fly-ash concrete has also been developed.
Comparative study of accelerated carbonation of plain cement and fly-ash concrete
(Elsevier, 2017-03) Singh, Shamsher Bahadur; Bhunia, Dipendu
Accelerated carbonation of plain cement concrete and concrete with fly-ash replacing cement partially, is discussed in the present paper. Mechanical properties such as compressive strength, flexural strength, modulus of elasticity, durability aspects such as depth of carbonation and porosity of carbonated concrete are studied. To study the influence of water binder ratio on the above-mentioned properties, water-binder ratios of 0.35, 0.50 and 0.65 are used. It is observed that the mechanical properties of carbonated concrete have increased with the duration of carbon dioxide exposure. So did the depth of carbonation, whereas the volume of permeable voids has reduced leading to the decrease in porosity. An expression to predict the depth of carbonation of fly-ash concrete has also been developed.
A Conceptual Design Approach of Coupled Shear Walls
(Hindawi Publishing Corporation, 2013) Bhunia, Dipendu
The growth of population density and shortage of land in urban areas are two major problems for all developing countries including India. In order to mitigate these two problems, the designers resort to high-rise buildings, which are rapidly increasing in number, with various architectural configurations and ingenious use of structural materials. However, earthquakes are the most critical loading condition for all landbased structures locatedinthe seismically active regions. The Indian subcontinent is divided into different seismic zones as indicated by IS 1893 (Part 1) [1], facilitating the designer to provide adequate protection against earthquake. A recent earthquake in India on January 26th, 2001 caused considerable damage to a large number of RCC high-rise buildings (number of storey varies from 4 to 15) and tremendous loss of life. The reasons were (a) most of the buildings had soft and weak ground storey that provided open space for parking, (b) poor quality of concrete in columns, and (c) poor detailing of the structural design (http://www.nicee.org/eqeiitk/ uploads/EQR Bhuj.pdf).
EFFECT OF SAND REPLACEMENT BY MILL SCALE ON THE PROPERTIES OF CONCRETE
(International Journal of Engineering Technology Science and Research, 2015-03) Bhunia, Dipendu; Singhal, Anupam
Concrete is the most widely used construction material in the world. This popularity of concrete carries with it an immense environmental cost. Billions of tons of natural materials are mined and processed each year to be used in concrete, which leaves a substantial mark on the environment. Efforts to use suitable recycled materials as substitutes for concrete aggregate are gaining in importance, such as recycled concrete aggregate, post-consumer glass, tires, etc. But one waste material which has not been extensively tested yet is mill scale. Mill scale is a flaky hazardous solid waste formed on the steel’s surface during the steel manufacturing processes. This work aims to evaluate the use of mill scale in Portland cement concrete, as a replacement for natural fine aggregates. Cement mortars with mix proportioning 1:3 were prepared varying the mill scale content of fine aggregate form 0% to 100%, for determination of compressive and tensile strength. The water/cement ratio used was 0.5 for all mix proportions. The compressive strength at different proportions did not give a general trend and two peaks were obtained at 60% replacement and 100% replacement. Maximum tensile strength was observed at 60% replacement of standard sand. A mix design was also done for M35 grade of concrete by the IS method. OPC of 43 grade was selected and sand replacement was done with mill scale varying from 0% to 80% with a suitable water cement ratio of 0.40. The compressive strength was measured after 28 days of completion of curing. Maximum strength was obtained for 40% sand replacement. Moreover, concrete with mill scale has demanded greater water content to maintain the workability.
Evaluation of marble slurry incorporated concrete using nondestructive methods
(Elsevier, 2017) Srivastava, Anshuman; Bhunia, Dipendu
Marble processing industry is one of most important industries of Rajasthan region in India. This industry produces large amounts of waste in the form of marble slurry. The waste slurry is dumped along the road sides thus causing environmental and health problems in the surrounding areas. Waste marble slurry is a material which helps in partially replacing cement in concrete thus promoting the utilization of a waste material and also reducing the use of cement. This paper shows the use of waste marble slurry as a partial replacement of cement in concrete with mainly two water cement ratios 0.40 and 0.45. The percentage replacement of cement is varied from 10 to 30 percent. Concrete is tested for compressive strength at 7 and 28 days. Non Destructive tests namely Rebound hammer and Ultrasonic Pulse velocity tests are also performed on the cubes to study the strength and quality of concrete produced. The results show that concrete with 15% marble dust as a partial replacement of cement gives 20% more strength than the control concrete. It is also seen that with increasing replacement of cement with waste marble slurry - slump decreases, density increases up to 15% replacement and then decreases. The quality of concrete improves according to UPV test. A relationship is developed between compressive strength and rebound hammer values for the marble slurry incorporated concrete. Therefore, this study shows that waste marble slurry could be a good source for use as partial replacement of cement in conventional concrete. This would help in sustainable growth and bulk utilization of what otherwise is a waste material.
An Experimental Investigation of Accelerated Carbonation on Properties of Concrete
(Eng. Journal, 2016) Singh, Shamsher Bahadur; Bhunia, Dipendu
This study deals with the effect of carbonation on the mechanical properties such as compressive strength, flexural strength and durability like depth of carbonation and volume of permeable voids of the concrete cast using ordinary Portland cement over a time period of up to 120 days. To study the behavior of carbonation front of concrete in presence of varying water content, water binder ratios of 0.35, 0.50 and 0.65 are chosen. It is observed that the volume of permeable voids of concrete has decreased, with an increase in compressive strength, flexural strength and depth of carbonation as the number of days of exposure of concrete specimen to high carbon dioxide increased.
An Experimental Investigation of Accelerated Carbonation on Properties of Concrete
(ENGINEERING JOURNAL, 2016) Bhunia, Dipendu; Singh, Shamsher Bahadur
This study deals with the effect of carbonation on the mechanical properties such as compressive strength, flexural strength and durability like depth of carbonation and volume of permeable voids of the concrete cast using ordinary Portland cement over a time period of up to 120 days. To study the behavior of carbonation front of concrete in presence of varying water content, water binder ratios of 0.35, 0.50 and 0.65 are chosen. It is observed that the volume of permeable voids of concrete has decreased, with an increase in compressive strength, flexural strength and depth of carbonation as the number of days of exposure of concrete specimen to high carbon dioxide increased.
Fired clay bricks synergistically valorizing hazardous nickel chrome-plating sludge and fly ash: Performance assessment
(Elsevier, 2024-04) Singhal, Anupam; Routroy, Srikanta; Bhunia, Dipendu; Lahoti, Mukund
Nickel Chrome Plating Sludge (NCPS) is a hazardous waste containing 25%-30% nickel and chromium. Previous attempts to immobilize NCPS into fired clay bricks resulted in weakened strength due to porosity and microstructure deterioration. This study introduces co-valorization of NCPS and fly ash in fired clay bricks to address these issues. Factory-scale firing of green bricks, alongside conventional clay bricks, assessed the commercialization potential. The optimal proportion of NCPS, fly ash, and clay was found to be as 12.5:37.5:50.0, respectively. Fly ash addition significantly improved brick properties, causing compressive strength to increase from 3.2 MPa to 11.6 MPa for a NCPS content of 12.5%. Microstructural analysis highlighted fluxing oxides in NCPS, amorphous silica-alumina in fly ash, synergistic ceramic bond formation, enhanced sintering and pore filling during vitrification. The study also demonstrated substantial fuel savings of 40%-50% due to NCPS's high heat of combustion causing internal firing of green bricks. The developed bricks exhibited almost double linear attenuation coefficients, indicating enhanced gamma radiation shielding. Leaching tests confirmed successful heavy metal immobilization. This co-valorization approach not only overcomes previous drawbacks but also offers significant environmental and economic benefits in utilizing NCPS in brick production.
Influence of activator ratios and concentration on the physio-mechanical and microstructural characteristics of the geopolymers derived from sandstone processing waste
(Springer, 2024-03) Bhunia, Dipendu; Lahoti, Mukund; Chakraborty, Sayantan
Natural stones have been utilized to meet various needs of human civilization since ancient times. The exploitation of any resource is associated with the production of redundant materials called wastes. Sandstone waste (SW) is one such waste obtained during the industrial processing of sandstones. Due to its siliceous composition, extensive yield, and disorganized dumping, noxious conditions related to land and human health are promoted. However, the lack of comprehensive engineering studies, mineralogical analysis, and design methodologies associated with the utilization of sandstone processing wastes restricted their applicability only to fillers or partial substitutes with pozzolans and traditional cement in meager volumes. In the past, limited efforts have been made to utilize SW as a construction entity, particularly for binding purposes. Thus, to enhance the scope of its utilization, a comprehensive investigation has been performed in this research to transform sandstone waste into a novel construction material by geopolymerization. Mix design tailoring and laboratory tests were implemented to understand the effects of sodium hydroxide concentration and sodium silicate to sodium hydroxide ratio on the dissolution and physio-mechanical characteristics of SW-based geopolymers. The activator-to-binder ratio was restricted to 0.4 to obtain pastes with sufficient workability without hindering the properties of the matrix. Besides, a high temperature-curing regime was selected based on SW's crystallographic and reactivity analysis. Subsequently, a total of 48 samples were prepared and tested at the curing age of 28 days. Detailed characterization of SW and SW-based geopolymer samples was performed using optical, X-ray, and infrared spectroscopies aided by electron imaging and thermogravimetric techniques. SW-based geopolymer samples showed compressive strengths in the range of 6-12 MPa, ~2 to 3 times higher than those obtained in previous experimentations. Phase analysis and microstructural examinations confirmed SW's participation in geopolymerization. Overall, it could be advocated that geopolymerization is an innovative approach for solving issues related to the disposal and re-utilization of SW, extending its possible application to the fields of cement mixes, wall tiles, mortars, and masonry as per the commendations of ASTM and ACI committee.
Investigation into the Behavior of Coupled Shear Walls
(Taylor & Francis, 2018-03) Bhunia, Dipendu
An effective design technique for symmetrical coupled shear walls is presented in this paper. The proposed formulation, including assumptions and steps with mathematical formulation, has been elaborated to arrive at the design technique. An example has been considered to validate the technique with the DRAIN-3DX and SAP non-linear analysis. A parametric study has also been considered to find out the limitations of this technique and suggest remedial action. It is concluded that the proposed design technique can be considered in the design of coupled shear walls under seismic motion.
Investigation of the behavior of conventional reinforced coupling beams
(Begell House, 2013) Bhunia, Dipendu
Coupled shear walls consist of two shear walls connected intermittently by beams along the height. The behavior of coupled shear walls is mainly governed by the coupling beams. The coupling beams are designed for ductile inelastic behavior in order to dissipate energy. The base of the shear walls may be designed for elastic or ductile inelastic behavior. The amount of energy dissipation depends on the yield moment capacity and plastic rotation capacity of the coupling beams. In this paper, an analytical model of the coupling beam has been developed to calculate the rotations and moment capacities of coupling beams with conventional reinforcement.
Investigation of the location of a shear wall in an rcc medium-rise building
(Begell House, 2011) Srivastava, Anshuman; Bhunia, Dipendu
Shear wall systems are among the most commonly used lateral-load resisting systems in high-rise buildings. Shear walls have very high in-plane stiffness and strength, which can be used to simultaneously resist large horizontal loads and support gravity loads, making them quite advantageous in many structural engineering applications. Many references are available concerning the design and analysis of a shear wall. However, the decision about the location of a shear wall in a multistorey building is not much discussed in any of them. In this paper, therefore, the main focus is to determine the shear wall location in a multistorey building based on its elastic and elastoplastic behaviors. An earthquake load is calculated and applied to a building of fifteen stories located in zone IV. Elastic and elastoplastic analyses were performed using both STAAD PRO 2004 and SAP2000 (2006) software packages. Shear forces, bending moment, and storey drift were computed in both cases and the location of a shear wall was established based upon the above computations.
An investigation on effect of partial replacement of cement by waste marble slurry
(Elsevier, 2017-03) Srivastava, Anshuman; Bhunia, Dipendu
In this study, waste marble slurry from Makrana region of Rajasthan in India is characterized for various physiochemical properties and used to replace cement partially by weight in concrete. Effects of marble slurry on hydration process, fresh and hardened concrete properties and durability properties using indigenously fabricated equipment are investigated. Effect of particle size of marble slurry on compressive strength and experimental trials on reinforced concrete with dried marble slurry are also conducted. No significant effect on characteristics of cement pastes is noted. Drying shrinkage is found to decrease and strength of mortar improves for a certain percentage replacement. Marble slurry is found to show filler effect by giving the concrete a denser and even structure. It is observed that the mechanical properties of concrete enhanced with incorporation of dried marble slurry for up to 15% replacement. The quality of concrete improves as per ultrasonic pulse velocity and durability tests. Reinforced concrete with marble slurry also shows promising results with increased bond strength. Finally, a compressive strength prediction model is developed using artificial neural network (ANN). The results for ANN are plotted as experimentally evaluated 28 days’ compressive strength versus predicted compressive strength.
Kiln-fired clay bricks synergizing nickel–chromium plating sludge and fly ash: mechanical characteristics and cradle-to-gate life cycle assessment
(Springer, 2022-09) Bhunia, Dipendu; Routroy, Srikanta; Singhal, Anupam; Lahoti, Mukund
Life cycle assessment (LCA) of novel fired clay bricks with synergistic co-valorization of nickel-chrome plating sludge (NCPS) and fly ash (FA) is reported. 0%, 20%, and 37.5% FA was added to improve sludge-deteriorated mechanical properties. Sludge bricks (SBs) exhibited compressive strength of 11.03 MPa, 17% water absorption, nil efflorescence, and permissible heavy metals’ leaching, complying with standards as first-class bricks. LCA was performed with the ReCiPe-2016 method, utilizing the primary experimental data, government reports, and the Ecoinvent v3.8 database. LCA analysis revealed that compared to clay bricks, SBs caused 30%, 43%, and 51% lesser harm to ecosystem quality, human health, and resource categories in the endpoint assessment. Kiln emissions, coal, clay, and transportation were chief contributors, but their cumulative endpoint impacts significantly reduced (38%, 52%, 55%, and 45%) on switching to the SBs. Terrestrial acidification, global warming, photochemical oxidant formation, and particulate matter emissions significantly affected midpoint categories. However, their impacts got reduced by 52–57% with SBs. With global annual clay brick production exceeding 1.5 trillion, agricultural soil mining causes irreversible depletion of nitrogen, phosphorous, potassium, and organic carbon in the soil. SBs utilize only 50% clay, adding substantially to environmental savings. Successful NCPS immobilization in bricks prevents leaching hazards and avoids scientific landfill construction. With a calorific value of 945 kcal/kg, NCPS acts as internal fuel during firing, reducing the external coal requirement. This work establishes the techno-environmental feasibility of recycling NCPS and producing better-performing bricks with lower environmental impacts.
Mechanical strength and durability of mineral admixture concrete subjected to accelerated carbonation
(Taylor & Francis, 2018-02) Bhunia, Dipendu; Singh, Shamsher Bahadur
Based on the experimental evaluation of blended cement concretes, its vulnerability to the potential carbonation threats have been discussed in this paper. Water binder ratios of 0.35, 0.50, and 0.65 have been adopted to study the mechanical properties and durability of the concrete mixes exposed to accelerated carbonation. Equations to predict the depth of carbonation under controlled conditions for these mixes have been established. The reliability of square root t law of diffusion to address the ingress of carbon dioxide into concrete has also been studied. Furthermore, conclusions have been drawn that the addition of fly ash and blast furnace slag as a partial replacement of cement decreased the carbonation resistance of concrete unless a water binder ratio of 0.35 is used, in which case the depth of carbonation remained almost same.