Faculty Publications

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Author: search.filters.author.Mithun, B.M.Subject: search.filters.subject.Mechanical properties

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    Influence of silica fume on the strength of betostyrene mixed concrete
    (2013) Sambo, A.G.; Deepak, T.J.; Mithun, B.M.
    The main objective of this paper is to determine the influence of silica fume (SF) on betostyrene mix concrete. Extensive experimentation was carried out to determine the influence of SF on the workability, compressive strength and flexural strength of concrete at constant water-binder ratio of 0.40 and SF additive of 0%, 5%, 10%, and 15%. For all mixes, slump test, compaction factor, compressive and flexure strengths were determined at 7, 14 and 28 days. The results showed that the compressive and flexure strengths increased with silica fume incorporation. This study comprehensively produced lightweight concrete and showed a rise in strength as in direct proportionality to the increase in silica fume. Workability fell to a rising amount of silica fume. © 2013 CAFET-INNOVA TECHNICAL SOCIETY.
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    Studies on eco-friendly concrete incorporating industrial waste as aggregates
    (Elsevier B.V., 2015) Palankar, N.; Ravi Shankar, A.U.; Mithun, B.M.
    The present day research is focussed on development of alternative binder materials to Ordinary Portland Cement (OPC) due to huge emissions of green house gases associated with production of OPC. GGBFS-FA based geopolymer binders are an innovative alternative to OPC which can obtain high strengths apart from being eco-friendly; since its production does not involve high energy and also contributes to sustainability by using the industrial waste materials. Steel slag, an industrial by-product obtained from manufacture of steel can be identified as an alternative to natural aggregates for concrete production, since there is a possibility of acute shortage of natural aggregates in future. The present study is conducted to evaluate the performance of weathered steel slag coarse aggregates in GGBFS-FA based geopolymer concrete. GGBFS-FA geopolymer concrete with steel slag coarse aggregates are prepared by replacing natural granite aggregates at different replacement levels i.e. 0%, 25%, 50%, 75% and 100% (by volume) and various fresh and mechanical properties are studied. The flexural fatigue behaviour of GGBFS-FA geopolymer concrete with steel slag is also studied in detail. Efforts are also made to model the probabilistic distribution of fatigue data of GGBFS-FA geopolymer concrete at different stress levels using two parameters Weibull distribution. The results indicated that incorporation of steel slag in GGBFS-FA geopolymer concrete resulted in slight reduction in mechanical strength. The water absorption and volume of permeable voids displayed higher values with inclusion of steel slag. Reduction in number of cycles for fatigue failure was observed in geopolymer concrete mixes containing steel slag as compared to granite aggregates. Overall, the performance of steel slag was found to be satisfactory for structural and pavement application and steel slag can be recognised as new construction material. © 2015
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    Air-cured Alkali activated binders for concrete pavements
    (Chinese Society of Pavement Engineering, 2015) Palankar, N.; Ravi Shankar, A.U.; Mithun, B.M.
    The present study focuses on the possibility of use of alkali activatedbinders for use in concrete pavements. Alkali Activated Slag Concrete (AASC) and Alkali Activated Slag Fly ash Concrete (AASFC) are prepared and the properties are compared with Ordinary Portland Cement Concrete (OPCC). The Ground Granulated Blast FurnaceSlag (GGBFS) and Fly Ash (FA) are blended in the ratios 100:0, 75:25, 50:50 and 25:75 as binder and activated using strong alkaline solution. Trial mixes are carried out to identify the optimal Activator Modulus (Ms) for each combination of GGBFS and FA. The mix design for the optimal activator modulus is optimised to achieve sufficient strength for Pavement Quality Concrete (PQC) and the fresh and mechanical properties are studied in detail. The results indicate the properties of AASC and AASFC are similar or slightly better than conventional OPCC and satisfy the minimum strength requirements for concrete pavements. The application of alkali activated binders will minimise the environmental hazards occurring from augmented OPC production, along with effective utilisation of industrial waste materials and conservation of natural resources. © Chinese Society of Pavement Engineering.
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    Performance of alkali activated slag concrete mixes incorporating copper slag as fine aggregate
    (Elsevier Ltd, 2016) Mithun, B.M.; Narasimhan, M.C.
    In this present study, copper slag (CS) is proposed as an alternative to river sand as fine aggregate in alkali-activated slag concrete (AASC) mixes. The relative performance of alkali activated slag concrete mixes with CS as fine aggregate is compared to conventional Ordinary Portland Cement concrete (OPCC) mix in terms of their workability, strength and durability parameters. The results indicate that, AASC mixes with CS, as a replacement to sand upto 100% (by volume), show no marked loss in strength characteristics. AASC mixes with either sand or CS possess similar modulus of elasticity, lower total porosity, lesser water absorption and reduced chloride ion penetration as compared to OPCC. Strength-retention characteristics of AASC mixes with sand/CS on exposure to sulphate and acid-rich environment are also studied. Use of AASC mixes for structural application reduces carbon footprint, decreases water consumption and cost. Use of CS as fine aggregate reduces river sand consumption as an added benefit. © 2015 Elsevier Ltd. All rights reserved.
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    Investigations on Alkali-Activated Slag/Fly Ash Concrete with steel slag coarse aggregate for pavement structures
    (Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2017) Palankar, N.; Ravi Shankar, A.U.; Mithun, B.M.
    The present investigation is conducted to evaluate the effect of steel slag coarse aggregates on mechanical properties and fatigue behaviour of Alkali-Activated Slag Fly Ash Concrete (AASFC) mixes. AASFC mixes were prepared with steel slag coarse aggregates by replacing natural coarse aggregates at various replacement levels (0, 25, 50, 75 and 100% by volume). Various mechanical properties and fatigue performance were tested and compared with conventional Portland concrete. The incorporation of steel slag aggregates resulted in decrease in mechanical strength of AASFC mixes. The fatigue lives of AASFC mixes containing steel slag were found to be lower than AASFC with natural coarse aggregates. Two-parameter Weibull distribution was used for statistical analysis of fatigue data and it was observed that the fatigue data of concrete mixes can be approximately modelled using Weibull distribution. Steel slag aggregates reported acceptable performance in AASFC mixes for its use in pavement quality concrete. © 2015 Informa UK Limited, trading as Taylor & Francis Group.
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    Alkali activated concrete with steel slag aggregate for concrete pavements
    (Science Publishing Corporation Inc ijet@sciencepubco.com, 2018) Palankar, N.; Mithun, B.M.; Ravishankar, A.U.
    In the present study, an attempt is made to investigate the usability of steel slag, which is a byproduct from the iron and steel industry, as coarse aggregates in alkali activated slag/ fly ash concrete mixes. The mix design for alkali activated slag/ fly ash concrete mixes was optimized and further steel slag coarse aggregates were incorporated in the optimized alkali activated slag/ fly ash concrete mixes mix by replacing natural coarse aggregates at different replacement levels (0%, 25%, 50%, 75% and 100% by volume). The mechanical properties were studied in detail. The flexural fatigue behavior of concrete mixes were investigated The experimental results showed that alkali activated slag/ fly ash concrete mixes with steel slag aggregates display slightly lower mechanical strength as compared to natural aggregates. The fatigue life of alkali activated slag/ fly ash concrete mixes was found to decrease with the inclusion of steel slag aggregates. The performance of steel slag aggregates in alkali activated slag/ fly ash concrete mixes was found satisfactory for use in pavement quality concrete. © 2018 Authors.