Conference Papers
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Item Forces due to short circuit in a 400 kV outdoor substation: A study(Institute of Electrical and Electronics Engineers Inc., 2018) Sudarshan, V.J.; Punekar, G.S.Short circuit force (SCF) in an EHV substation is an important attribute for the electromechanical design of a substation. Hence, computation of SCF becomes mandatory for the substation design. The conductor phase to phase spacing within the EHV substation is an important parameter which influences the SCF. Also, in a flexible-conductor-bus, in the event of a short circuit, there will be variation in of phase to phase air clearances (dynamic) and conductor-sag (dynamic). The air clearances at any conditions should satisfy the minimum phase to phase clearance as per standard to assure safety and avoid secondary faults. The conductor-sag should also be within acceptable limits. As the conductor phase to phase spacing is varied, air clearances as well as conductor sag varies. The SCF in a 400kV substation, with flexible-bus-conductor's, is computed as a case study. With this SCF, variation in air clearances and conductor-sag are computed and analyzed. The margin given in design and construction of bus conductor spacing and their sag during static conditions are good enough even under the short circuit conditions resulting in SCF and reduced conductor spacing due to dynamic reduced phase to phase clearances and sags. © 2018 IEEE.Item Short circuit force in an AIS with special reference to L-L and L-L-L faults(Institute of Electrical and Electronics Engineers Inc., 2018) Sudarshan, V.J.; Punekar, G.S.Short circuit force (SCF) in an air insulted substation is a feature which is of importance in its electromechanical design. SCF which are generated due to short circuit current is transferred from conductors (flexible or rigid) to end connections where the conductors are being held. The end connections and the conductor are supported by means of insulator, steel structure, and foundation. Thus, SCF is transferred from conductors to end connections and then to steel structures via insulator. If estimation of SCF is erroneous, then the end result will be a disaster (as the structural designs are based on this). On the other hand, too much conservative structural designs based on the estimated SCF results in increased size and cost of insulators, steel structure, and foundation requirements. Hence, the computation of SCF becomes mandatory in design of the substation from the reliability and economic considerations. In this paper, SCF in a 400 kV air insulated (upcoming) substation (in Africa) due to line-to-line short circuit currents and three phase short circuit currents on flexible conductor are computed using basic electromagnetic laws and are discussed. The computed values are compared with the values of SCF obtained as per IEC 60865 standard. © 2018 IEEE.Item Constructive scope on implementation of copper slag as replacement for natural fine aggregate—an overview(Springer Science and Business Media Deutschland GmbH, 2021) Thilak Kumar, Y.T.; Arpitha, D.; Sudarshan, V.J.; C, C.; Puttaswamy, N.This paper communicates organized work on copper slag drawn from scientific literature which comprises evaluation of physical and chemical characteristics, mechanical and durability properties in the marine environment. Analysis of test data derived from previously available sources reveals that copper slag having similar basic characteristics is an acceptable alternative material to river sand to produce concrete of all grades. The lesser water absorption property of copper slag is very significant peculiarity which attributes to develop high strength in concrete. The behaviour of concrete produced using copper slag to the concrete made corresponding to sand component shows identical behaviour in the fresh and hardened states. As an aggregate, copper slag has an ability to be replaced with fine aggregate, thereby the advance progress in the concrete technology will revolutionize the mixture of different conventional ingredients to uplift the expected properties of concrete to renew its definition. Hence, alternative materials to be used as fine aggregate will reduce the burden on the environment which is being extensively investigated all over the world looking to the significant requirements, quality and properties which have been a global consensus on the materials. © Springer Nature Singapore Pte Ltd 2021.Item Assessment on performance of steel slag and processed granulated blast furnace slag as an alternative for fine aggregate—an assertive review(Springer Science and Business Media Deutschland GmbH, 2021) Sudarshan, V.J.; Arpitha, D.; Thilak Kumar, Y.T.; C, C.; Puttaswamy, N.Sand has always been an integral part of construction in our civilization. It has been the most easily available and acceptable source for the same. However, the depletion of river sand availability has started looking at the alternatives including some industrial by-products. One of them is slag obtained from manufacture/refining of metals which would help in the utilization of industrial waste and conservation of natural resources to have a sustainable construction. This paper provides the gist of organized overview involving the evaluation of physical and chemical characteristics, assessment of mechanical and durability properties for the effective utilization of steel slag and processed granulated blast furnace slag (PGBS) that could be modelled from previous researches related to the study. The basic properties of steel slag and PGBS exhibit requisite properties like river sand which is an indication for a possible alternative material to the conventional aggregate. The multiple processing of slag has its influence on strength, durability, and workability of concrete. These recent innovations have made the slag economically viable and environmentally friendly, and also profitable salvaging of processed by-product. © Springer Nature Singapore Pte Ltd 2021.Item Influence of Superplasticizers on Blended Cement and Their Effect on Flow Characteristics by Incorporating PGBS as Partial Replacement for Fine Aggregates(Springer Science and Business Media Deutschland GmbH, 2021) Arpitha, D.; Sudarshan, V.J.; Thilak Kumar, Y.T.; C, C.Currently the upsurge practice of the mineral admixtures as an alternative for cement to cut down the carbonic gas emission, to reduce the cement cost, and to progress some technical recitals is truly the indispensable novelty advanced in construction industry. Mortars with different w/c require the use of appropriate and compatible chemical admixtures to achieve desirable consistency. The principal tactic delivered to contest in contradiction to this exertion is to choose the furthermost effective twosome cement–superplasticizer, facilitating to attain a determined water reduction, an enhanced flow, and an adequate rheology. Processed Granulated Blast Furnace Slag (PGBS) incorporated as partial replacement for Fine Aggregates (FA) along with different types of Superplasticizers (SP) for different dosages, which were chemically based on Lignosulfonate (LS), Sulphonated Naphtha Formaldehyde (SNF), and Polycarboxylate Ether (PCE), was used to check the behavior of flow characteristics in this work. The fusion of Portland pozzolana cement (PPC) along with partial replacement of fine aggregates has resulted to understand the better flow interaction between the cementitious materials and under different water–cement ratio (w/c). © 2021, Springer Nature Singapore Pte Ltd.Item Investigations on Flow Characteristics of Mortars Using Partial Replacement of Fine Aggregates with Processed Granulated Blast Furnace Slag(Springer Science and Business Media Deutschland GmbH, 2021) Sudarshan, V.J.; Arpitha, D.; Thilak Kumar, Y.T.; C, C.; Puttaswamy, N.Sand has always been an integral part of construction in our civilization. It has been the most easily available and acceptable source for the same. However, the depletion of river sand availability has led us to start looking at the alternatives including some industrial by-products. Processed Granulated Blast Furnace Slag (PGBS) is an alternative slag sand for fine aggregate which is being extensively utilized. Low density and strength issues concerned with Granulated Blast Furnace Slag (GBS) have led to the innovation of PGBS. PGBS is considered as an economically viable and environmentally acceptable alternative material for replacing river sand having tremendous economic impact, conservation of natural resources, and gainful recycling of process by-products. In this study, mini slump cone test is conducted for mortars using 10, 20, 30, and 40% partial replacement of Fine Aggregates (FA) (River sand) with PGBS to study the flow behavior and to identify the suitable combinations of water binder ratio (W/B) (0.4, 0.45, and 0.5) and superplasticizer dosage (0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0). © 2021, Springer Nature Singapore Pte Ltd.Item Study on Compatibility Issues and Flow Behavior of Copper Slag-Based Mortars(Springer Science and Business Media Deutschland GmbH, 2021) Thilak Kumar, Y.T.; Arpitha, D.; Sudarshan, V.J.; C, C.; Puttaswamy, N.With the growing constructions industries, sand availability has become a headache for the builders and engineers. In this paper an attempt has been made to understand the flow characteristics of partially replaced copper slag (10, 20, 30, and 40%) in mortars with varied water binder ratio (0.35, 0.4, and 0.45) for different percentages of superplasticizers dosage (0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0). Thus, the test results drawn help to identify the optimum dosage of superplasticizer required for different percentage replacement of fine aggregates and water binder ratio and understand the flow behavior characteristics of mortars. © 2021, Springer Nature Singapore Pte Ltd.