Department of Civil Engineering

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Author: search.filters.author.Srivastava, AnshumanSubject: search.filters.subject.Civil Engineering

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Now showing 1 - 10 of 24
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    Properties of fly ash geopolymer modified with red mud and silica fume: a comparative study
    (Springer, 2020-10) Srivastava, Anshuman
    Alkali-activated geopolymer has emerged as a sustainable alternative to highly polluting conventional cement. The present paper investigates the activation of fly ash-based geopolymer paste modified by red mud and silica fume. Three geopolymer mixes are considered: (1) fly ash; (2) fly ash—red mud; and (3) fly ash—silica fume. Mass proportions of modifiers in the respected mixes varied by 0, 5%, 10%, 15%, 20%, and 25% of total binder. Heat curing (60 °C) provided for 24 h just after casting. Alkaline activator consists of sodium hydroxide and sodium silicate solutions. Workability results reveal that both red mud and silica fume triggered the reduction in workability with the later one had a greater impact. A flash set was obtained with the silica fume content of more than 15%. Both the modifiers cause a decrease in the setting time at ambient temperature, and silica fume proved to be more productive with the reduction of more than 65% of setting time. Mixes containing red mud exhibit slightly higher density. Water absorption of fly ash geopolymer increases with red mud. Compressive strength increases with the addition of modifiers, and geopolymer containing silica fume possesses the highest compressive strength among the three mixes considered. Compressive strength exhibited a linear correlation with molar ratios (Si/Al and Na/Si) of source materials. XRD and SEM methods showed that the geopolymerization reaction is affected by the red mud and silica fume. It is recommended that the flash set and setting time at higher contents of modifiers must be examined for the design of a modified geopolymer mix.
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    Use of Photocatalyst in Self-Cleaning Constructions Material: A Review
    (Springer, 2022-03) Singh, Shamsher Bahadur; Srivastava, Anshuman
    Pollution arising from the urban activities and industry has a significant impact on the aesthetic view of building and quality of life. This study reviews the framework, problem, challenges, and benefits of self-cleaning construction materials. The present study gives the critical review analysis of the relevant literatures considering the self-cleaning concrete properties, process, and critical assessment of different approaches of self-concrete techniques. Recently, studies based on self-cleaning concrete have provided alternative for traditional concrete. Specifically, use of “Photocatalyst” as a self-cleaning” agent has revolutionized the concrete industry. The self-cleaning properties of photocatalyst, e.g., TiO2, Bismuth, and ZnO have been investigated and compared. These photocatalysts activated by ultraviolet (UV) radiation can result in increased organic particulates decomposition. They check the level of pollutants like NOx, SO2, and Volatile Organic Compound and keep the air pollution free. It is concluded that Bismuth (Bi2O2CO3) photocatalyst gives better result in self-cleaning than TiO2 and ZnO.
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    Condition Assessment of Reinforced Concrete Bridge Deck Using Infrared Thermography
    (Springer, 2022-05) Singh, Ajit Pratap; Srivastava, Anshuman
    Estimation of extent of deterioration in concrete bridge decks is a challenge. Non-destructive testing (NDT) techniques are significant since they provide fast, easy, and economical way to detect delaminations, cracks, voids, and corrosion in bridge decks. In the present work, an attempt has been made to assess the effectiveness of infrared thermography (IRT) method in detecting various subsurface flaws of bridge decks. Thus, a test facility containing concrete bridge deck induced with various artificial defects is constructed. This study concludes that IRT can quickly scan large areas and identify potential locations of defects, particularly at shallow depths, up to 50 mm depth from surface in this study. Therefore, it can be highly useful for field inspections of bridges. The ideal time for field testing is estimated to be 4–5 h after sunrise. However, it can be suitably used along with other NDT techniques and their combination would yield better results.
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    Reliability-based mix design of marble dust incorporated concrete and its assessment using the concept of performance index
    (Wiley, 2022-03) Srivastava, Anshuman
    Concrete is one of the most important and versatile construction materials and variation in its properties is inevitable. Mix design of concrete is done in such a way that the design compressive strength is typically higher than the actual values specified by the structural engineer. The concept of reliability has not been explicitly used in regard of calculation of compressive strength using mix design and demands attention. A design procedure based on the reliability-based index is presented. The design procedure is developed for the concrete mix with partial replacement of cement by marble dust. The mechanical property which is the compressive strength of the concrete mix design is considered as a random variable, assumed to be lognormally distributed. The present study makes an effort to design a concrete mix in accordance to theory of confidence level for various levels of reliability. Mix design guidelines and graphs for various levels of replacement of cement by marble dust have also been presented in the study. Also, the cost analysis of various design mix proportions used has been calculated and compared. Four different cases to illustrate the performance rating in accordance with replacement levels of Marble dust have been formulated. The concrete mixes with marble dust induced in concrete had lower partial safety factors than those without inclusion. The characteristics of Marble dust incorporated concrete have been assigned numerical performance index values. These values may constitute a reliable means for concrete producers in finding the rate of cement replacement by other cementitious materials. The compressive strength of most of mixes with marble dust had a coefficient of variation and within-test coefficient of variation value ranging between 2% and 3% and less than 1.5%, respectively. This indicates toward improvement in quality of concrete with cement partially replaced by marble dust.
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    Experimental investigation on paver blocks of fly ash-based geopolymer concrete containing silica fume
    (Taylor & Francis, 2021-12) Srivastava, Anshuman
    Utilisation of geopolymer may reduce the global warming potential of concrete. This study examines geopolymer concrete as interlocking paver blocks. Three concretes are compared: conventional cement, fly ash-geopolymer and fly ash–silica fume geopolymer. Sodium hydroxide solution is used in both geopolymer concretes, and sodium silicate solution is used in fly ash-based geopolymer concrete only. Rectangle and uni shape blocks are tested for compressive strength, flexural strength, abrasion resistance and freeze–thaw resistance. Dynamic drop loading test is conducted on block pavement with herringbone laying pattern . Results revealed that resistance to abrasion and water absorption of geopolymeris improved by adding silica fume . Freeze–thaw resistance is the lowest for cement concrete paver blocks. Lowest deflection occurred in block pavement of uni shape. Geopolymer concrete provides uniform load distribution than cement concrete. Cement concrete is slightly costlier than geopolymer concrete. This study concluded the geopolymer as suitable option for paver block applications
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    Bioconcrete-Enabled Resilient Construction: a Review
    (Springer, 2023-03) Lahoti, Mukund; Srivastava, Anshuman
    Concrete, the ubiquitous cementitious composite though immensely versatile, is crack-susceptible. Cracks let in deleterious substances causing durability issues. Superseding conventional crack-repair methods, the innovative application of microbially induced calcium carbonate precipitation (MICCP) stands prominent, being based on the natural phenomenon of carbonate precipitation. It is eco-friendly, self-activated, economical, and simplistic. Bacteria inside concrete get activated by contacting the environment upon the crack opening and filling the cracks with calcium carbonate—their metabolic waste. This work systematizes MICCP’s intricacies and reviews state-of-the-art literature on practical technicalities in its materialization and testing. Explored are the latest advances in various aspects of MICCP, such as bacteria species, calcium sources, encapsulations, aggregates, and the techniques of bio-calcification and curing. Furthermore, methodologies for crack formation, crack observation, property analysis of healed test subject, and present techno-economic limitations are examined. The work serves as a succinct, implementation-ready, and latest review for MICCP’s application, giving tailorable control over the enormous variations in this bio-mimetic technique.
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    Solution of Shear Wall Location in Multi­Storey Building
    (International Journal of Civil and Structural Engineering, 2011) Bhunia, Dipendu; Srivastava, Anshuman
    Shear wall systems are one of the most commonly used lateral­load resisting systems in high­ rise buildings. Shear walls have very high in­plane 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. There are lots of literatures available to design and analyse the shear wall. However, the decision about the location of shear wall in multi­storey building is not much discussed in any literatures. In this paper, therefore, main focus is to determine the solution for shear wall location in multi­storey building based on its both elastic and elasto­plastic behaviours. 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 SAP V 10.0.5 (2000) software packages. Shear forces, bending moment and story drift were computed in both the cases and location of shear wall was established based upon the above computations
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    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.
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    Solution of Shear Wall Location in Multi-storey Building”, International Journal of Civil and Structural Engineering,
    (International Journal of Civil & Structural Engineering, 2011) Srivastava, Anshuman; Bhunia, Dipendu
    Shear wall systems are one of 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. There are lots of literatures available to design and analyse the shear wall. However, the decision about the location of shear wall in multi-storey building is not much discussed in any literatures. In this paper, therefore, main focus is to determine the solution for shear wall location in multi-storey building based on its both elastic and elasto-plastic behaviours. An earthquake load is calculated and applied to a building of fifteen stories located in zone IV. Elastic and elasto-plastic analyses were performed using both STAAD Pro 2004 and SAP V 10.0.5 (2000) software packages. Shear forces, bending moment and story drift were computed in both the cases and location of shear wall was established based upon the above computations.
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    Potential Applications of Marble Dust in Industrial Use by Characterization Techniques – A Review
    (International Journal of Advanced Structures and Geotechnical Engineering, 2016) Srivastava, Anshuman; Bhunia, Dipendu
    Marble is a very common building material. In India, Rajasthan caters almost 85 % of the total demand of marble. It is normally a rich source of calcium carbonate which has various applications. Quarrying, processing and polishing of marble generates large amount of waste. This waste is dumped and left unattended thus creating hazardous problems. It is required to use this waste material in development of some value added products and reducing the impact on environment. Thus it is necessary to know the chemical properties of the waste left behind and how it reacts or helps in the hydration process. It is required to study the current uses of this waste marble dust in various industrial and construction practices. This paper describes various chemical properties of marble dust using characterization techniques like X-Ray Diffraction (XRD), X-Ray fluorescence (XRF), Thermo gravimetric Analysis (TGA) and Scanning Electron Microscope (SEM). Also the practical application of these characterization techniques in studying the chemical reactions taking place in mortars and concrete is reviewed. Suggestions for further studies and utilization in various fields for building a sustainable environment are also incorporated. It would encourage bulk utilization of waste marble dust as an alternative construction material which is otherwise a waste.