Faculty Publications
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Item Mechanical properties of fiber-reinforced concrete using coal-bottom ash as replacement of fine aggregate(Springer, 2019) Goudar, S.K.; Shivaprasad, K.N.; Das, B.B.The present investigation aims to study the significance of coal coal-bottom ash as a partial replacement to natural river sand in fiber-reinforced concrete (FRC). Hooked-end steel fibers were used to produce fiber-reinforced concrete at a fiber content of 1.5% by volume concrete. About 30% of natural sand was replaced with coal coal-bottom ash to produce M30 grade concrete with a water–cement ratio of 0.45. The prolonged curing period has a positive effect on the coal, coal-bottom ash replaced concretes. There was a slight increment in the compressive strength of FRC because of inclusion of steel fibers. However, significant improvements were observed in flexural and split tensile strength of FRC due to the inclusion of steel fibers. The optimum content of coal, coal-bottom ash replacement to natural sand was found to be 20%. © Springer Nature Singapore Pte Ltd. 2019.Item Study on Processed Granulated Blast Furnace Slag as a Replacement for Fine Aggregates for the Greener Global Construction(Springer Science and Business Media Deutschland GmbH, 2023) Arpitha, D.; C, C.; Kappadi, P.As innovation in concrete technology advances and the environment weakens, it is currently evident that the boundless utilization of construction materials and its initial expense being the common determination model has become a routine with regard to the past. Since there is great interest for raw materials and natural resources are rare, it is expected to utilize a high volume of alternative materials in concrete that would be monetarily beneficial like crushed sand, blast furnace slag, etc. An experimental investigation was carried out to examine the behaviour of mortars incorporating partial volumes of secondary material to fine aggregates. Processed granulated blast furnace slag (PGBS), newly processed slag which had overcome the limitations of granulated blast furnace slag obtained as a by-product during the extraction of steel was tested for fine aggregate (FA) replacement. Several combinations of mortar mixes were prepared using Lignosulfonate (LS), Sulphonated Naphthalene Formaldehyde (SNF) and Polycarboxylate Ether (PCE)-based superplasticizers (SP) for 0 and 50% replacement levels of FA by PGBS to recognize the feasible optimum dosage of SP required to achieve desired flow characteristics of mortars. Based on the optimum dosage of SP and w/c obtained, mortar cubes were prepared and cured for 3, 7, and 28 days. These cubes were tested for compressive strength periodically, the results revealed that PCE-based SP exhibited better performance concerning flow behaviour and strength gain parameters along with the effective reduction in w/c for both 0 and 50% FA replaced mixes. PGBS exhibited higher strength when compared to 0% replaced mixes though there was a slight increase in water content required for the cohesive mix. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Studies on iron tailings towards usage for paving blocks manufacture(2010) Mangalpady, M.; Sampath Kumar, N.N.Disposal of mill tailings is one of the major problems in mining industry. Investigations are being done all over the world to utilize tailings for useful purposes. The scope of this work is to study the utilization of iron ore tailings in manufacture of concrete paving blocks. Five reference mixes were prepared using cement, jelly dust and baby jelly. Ten paving blocks were prepared from each type of mix, out of which five specimens were cured for 7 days and five were cured for 28 days. By using sand and tailings as fine aggregates, two modified mixes were prepared by replacing jelly dust partly in reference mixes. Similar to reference mix, five mix ratios were made and ten paving blocks were prepared from each type of mixtures. From each set of paving blocks, five specimens were cured for 7 days and the other five specimens were cured for 28 days. Laboratory tests were conducted to assess water absorption and compressive strength of specimens, and graphs were plotted for their comparison among each type of respective mix ratios. In all the comparisons, compressive strength of tailing based mix was higher than the respective reference mix. Similar trend is shown by the graphs plotted for water absorption. © 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Usage potential of melt processed plastic pellets as a substitute to fine aggregate in porous concretes(2012) Maneeth, P.D.; Lokesh, G.; Yaragal, S.C.; Babu Narayan, K.S.Porous concrete (PC) has been used for over 30 years. Because of its high porosity, the most common usages have been in the area of storm water management, but have been limited to use in pavements with low volume traffic, because of its low compressive strength compared to conventional concrete. Domestic and industrial plastic waste management has posed a serious challenge to engineers and scientists today. In this study an attempt is made to utilize plastic waste (melt processed) from small industries as a substitute for fine aggregate (up to 10%) in producing porous concretes. The recycled plastic (melt processed) was produced by drawing industrial and domestic waste plastic into long strands which were cut to small pieces forming granules. The plastic granules (pellets) are used as substitute to sand in this investigation. This experimental investigation reports the scope for plastic waste utilization as a substitute for fine aggregate and its influence on properties like porosity, permeability, compressive strength and tensile strength of porous concretes. © 2012 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Influence of fineness of fly ash on compressive strength and microstructure of bottom ash admixed geopolymer mortar(Associated Cement Companies Ltd., 2018) Shivaprasad, K.N.; Das, B.B.; Renjith, R.Investigations were conducted to find out the suitability of bottom ash as a possible replacement to fine aggregates in geopolymer mortar. Experimental work was done to study the influence of fineness of fly ash (with three levels of Blaine's fineness, 2043 cm2/g, 2602 cm2/g and 3113 cm2/g on compressive strength and microstructure development of fly ash based geopolymer mortar with natural river sand and bottom ash as fine aggregates. three different water to solids ratios of 0.246, 0.349, and 0.443 were chosen for this study and the curing of the specimens was at ambient temperature (28 ± 3°c). compressive strength development for all eighteen mortar mixes was measured at 7, 14, 28 and 56 days. Further, the effect of fineness of fly ash on degree of polymerization, microstructure and properties of geopolymers was studied using Fourier transform Infrared Spectroscopy (FtIR) and Scanning Electron Microscopy (SEM). It was observed from the compressive strength of the geopolymer mortar that the degree of polymerization is gradual for both types of mortar. there is a continuous increase in the development of compressive strength noticed till the age of 56 days for both types of mortar, sand as well as bottom ash admixed. However, the increment of compressive strength for bottom ash found to be significantly less as compared to natural sand. Improvement in compressive strength due to fineness of fly ash were characterised by SEM and FtIR and it is revealed that with increase in fineness levels, the microstructure significantly enhanced the characteristics of geopolymer mortar. © 2018 Associated Cement Companies Ltd.. All rights reserved.Item Use of iron ore mine tailings in infrastructure projects(Inderscience Enterprises Ltd., 2019) Shubhananda Rao, P.; Gayana, B.C.; Ram Chandar, K.Utilisation of iron ore tailings in bricks as a replacement for sand will help in sustainable and greener development. The literature shows the potential use of iron ore tailings as a replacement of natural fine aggregates. As natural sand reserves are depleting day by day, there is a need for substitution for sand in bricks. A comprehensive overview of the published literature on the use of iron ore tailings and other industrial waste is being presented. The effects of various properties such as compressive strength, thermal conductivity and durability of bricks have been presented in this paper. © 2019 Inderscience Enterprises Ltd.Item Characterization and performance of processed lateritic fine aggregates in cement mortars and concretes(Elsevier Ltd, 2019) Yaragal, S.C.; Basavana Gowda, S.N.; C, C.Availability of river sand is becoming scarce, due to rapid increase in infrastructure projects in India. Acute shortage of river sand, has led to indiscriminate sand mining. Adverse effect of sand mining includes river bank erosion, river bed degradation, loss of biodiversity and deterioration of river water quality and ground water availability. To address the above issues, research efforts are on, to find substitutes for river sand to be used as fine aggregate in mortars and concretes. One among the locally available resources is laterite. Laterite is a product of tropical or sub-tropical weathering, which is an abundant soil material in many parts of India. An attempt has been made to characterize the processing technique to obtain good quality lateritic fine aggregates (lateritic FA). Experiments were designed and conducted to study the performance of lateritic FA as replacement to river sand, in cement mortars and concretes. Processed lateritic FA in replacement levels of 0, 25, 50, 75 and 100 wt% to river sand at all fineness levels (Zone I to Zone IV as per Indian standards) is considered. Microstructure studies were conducted to understand the arrangement of river sand and lateritic FA with cement matrix and their Interfacial Transition Zones (ITZ) using Scanning Electron Microscope (SEM). The workability and compressive strength characteristics of cement mortars and concretes are evaluated. Laterized mortars with Zone III and Zone IV fine aggregates, at all replacement levels, result in the same compressive strengths as those of control mortars. Suitable strength enhancement technique has been attempted to achieve strengths of Zone I and Zone II lateritic fine aggregates based mortars at 100 wt% replacement, to achieve strength at least equal to or more than those of control mortars. Laterized concretes have achieved nearly the same strengths as those of control concretes, at all replacement levels and for all fineness levels (Zone I to Zone IV). © 2018 Elsevier LtdItem Performance evaluation of cement mortar compositions at elevated temperatures(Associated Cement Companies Ltd., 2019) Yaragal, S.C.; Vivek, S.; Kumar, B.Natural river sand is becoming scarce day by day due to rapid growth in construction sector. There is need for alternatives to be used in place of river sand. The performance of alternatives to river sand at elevated temperatures is also important in the likely event of fire accidents. In this study, the effect of elevated temperatures on the compressive strength of mortars containing Crushed Rock Fines (CRF) and Lateritic Sand (LS) is investigated. Cement mortar cubes were cast for varied proportion of lateritic soil and quarry dust as fine aggregate. Lateritic content was varied from 25%-100%, and 50% quarry dust was adopted. After 28 days of water curing, specimens were exposed to temperatures of 200, 400, 600, and 800°C. At room temperature, the compressive strength decreases with increase in level of lateritic fine aggregate. The lateritic mortar mixes (50, 75, and 100%) have exhibited superior elevated temperature endurance characteristics at 400, 600, and 800°C when compared to control mix. Even the 25% laterized mortar has performed equally well as that of control mix. At elevated temperatures, CRF blended mix has performed very poorly. Mortar containing lateritic sand has potential for utilization in buildings and other structures, for better fire endurance in the likely event of fire accidents. © 2019 Associated Cement Companies Ltd.. All rights reserved.Item Experimental investigations on performance of concrete incorporating precious slag balls (PS Balls) as fine aggregates(Techno Press technop2@chollian.net, 2019) Sharath, S.; Gayana, G.B.; Reddy, K.R.; Ram Chandar, R.C.Substitution of natural fine aggregates with industrial by-products like precious slag balls (PS Balls) offers various advantages like technical, economic and environmental which are very important in the present era of sustainability in construction industry. PS balls are manufactured by subjecting steel slag to slag atomizing Technology (SAT) which imparts them the desirable characteristics of fine aggregates. The main objective of this research paper is to assess the feasibility of producing good quality concrete by using PS balls, to identify the potential benefits by their incorporation and to provide solution for increasing their utilization in concrete applications. The study investigates the effect of PS balls as partial replacement of fine aggregates in various percentages (20%, 40%, 60%, 80% and 100%) on mechanical properties of concrete such as compressive strength, splitting tensile strength, and flexural strength. The optimum mix was found to be at 40% replacement of PS balls with maximum strength of 62.89 MPa at 28 days curing. Permeability of concrete was performed and it resulted in a more durable concrete with replacement of PS balls at 40% and 100% as fine aggregates. These two specific values were considered as optimum replacement is 40% and also the maximum possible replacement is 100%. Scanning electron microscope (SEM) analysis was done and it was found that the PS balls in concrete were unaffected and with optimum percentage of PS balls as fine aggregates in concrete resulted in good strength and less cracks. Hence, it is possible to produce good workable concrete with low water to cement ratio and higher strength concrete by incorporating PS balls. © 2019 Techno-Press, Ltd.Item Waste-polymer incorporated concrete mixes for neutron and gamma radiation shielding(Elsevier Ltd, 2021) Malkapur, S.M.; Ghodke, S.S.; Sujatha, P.N.; Singh, Y.; Shivakumar, K.S.; Sen, M.; Narasimhan, M.C.; Pulgur, A.V.In this paper, attempts are made to use waste plastics to make a novel Waste Polymer Incorporated Concrete (WPIC) mixes for gamma and neutron radiation shielding purposes. These mixes are achieved by simultaneous incorporation of waste polymeric material and high density fine and coarse aggregate components from iron industry in place of conventional ingredients. The results have indicated that the waste plastics along with by-products of iron industry can be conveniently used to make concrete mixes which have acceptable compressive strength characteristics and significantly enhanced shielding capabilities with respect to both gamma and neutron radiations. © 2021 Elsevier Ltd