Faculty Publications
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Publications by NITK Faculty
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Item Significance of modeling techniques in pushover analysis of RC buildings(2010) Thapa, M.; BabuNarayan, K.S.; Halemane, K.P.; Venkataramana, K.; Yaragal, S.C.; Ramesh Babu, R.; Sharma, A.; Reddy, G.R.The study presented here focuses on the effectiveness of the models adopted for the nonlinear static pushover (NSP) analysis and providing the best model that can predict the nonlinear response of RC buildings with sufficient accuracy with respect to the experimentally obtained results. NSP analysis considers material nonlinearity and is an effective tool to evaluate the performance of the structure under lateral seismic loads. However, the actual test data in order to verify the results of NSP analysis are very rare for RC structures, which are analytically sensitive to the models and procedure adopted by the analyzer. Under the present work three cases of geometric models; a) Frame with beamcolumn elements, b) Frame with beam-column elements and slabs modelled as a rigid diaphragm and c) Frame with beam-column elements and slabs modelled as shell element considering concrete as confined and unconfined were analyzed. Comparision of analytical curve with the experimental pushover curve, clearly suggests that frame modelled as confined beam-column elements and slabs modelled as a rigid diaphragm gives closer results. © 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Performance evaluation of rebar in accelerated corrosion by gravimetric loss method(2012) Shetty, A.; Venkataramana, K.; Gogoi, I.Corrosion of concrete occurs due to chloride ingress into concrete and is a major cause of steel corrosion. Rebar corrosion in concrete is one of the major problems in the durability criteria. This paper explains, experimental investigations carried out on smaller specimens for evaluating the performance of two types of cement with three types of rebar by gravimetric method. From the results of gravimetric loss obtained by different types of steel with different types of concrete, it is concluded that blended cement, i.e. PPC performs better compared to OPC against accelerated rebar corrosion in concrete. Amongst steel types, CTD steel resulted in higher gravimetric loss compared to MS followed by TMT steel. © 2012 Cafet-Innova Technical Society. All rights reserved.Item Experimental investigation of RC frames using CFRP sheets(2013) Prashanth, M.H.; Babu Narayan, K.S.; Venkataramana, K.; Sajith, M.Reinforced Concrete frames are the main load resisting systems used in practice all over the world. These frames will be subjected to sway, due to lateral loading most of the times by either earthquake or wind. Ductility and energy dissipation capacity of the frame are the key parameters for better performance under the action of the sway loading. Retrofitting using the new generation material such as carbon fiber reinforced plastic sheets (CFRP) shows much enhancement in these properties of laterally loaded frames. Frames subjected to lateral loading introduce collapse mechanism due to the formation of the plastic hinges at critical hinge locations. An experimental investigation of partially and fully CFRP wrapped reinforced concrete (RC) frames when compared to conventional(bare) frame has been carried out, to bring out the importance of critical engineered locations to be wrapped. © 2013 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Bond strength behaviour in reinforced concrete members exposed to corrosive environment - An overview(2013) Shetty, A.; Venkataramana, K.; Babu Narayan, K.S.; Kimura, Y.Bond resistance of reinforcing bars, embedded in concrete depends primarily on frictional resistance and mechanical interlock. Corrosion of rebars in concrete is one of the major problems in the durability criteria. Local bond stress slip relationship is generally adopted to determine the mechanical properties of the interface between re-bars and concrete. Therefore the attainment of satisfactory performance in bond is an important, aspect of the design and the detailing of reinforcement in structural components. In this paper an overview of factors affecting specimen geometry of bond strength and Types of bond tests were studied. © 2013 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Studies on the dynamic characteristics of monolithic RC wall panels(2013) Amitha, S.B.; Chethan, K.; Bhavanishankar, S.; Annapurna, B.P.; Venkataramana, K.; Ramesh Babu, R.Monolithically built RC wall panels permits for the industrialized construction of a group of integrated buildings using mechanized, rationalized and mass-production procedure. This is a unique, fast and economical technique. Most of the national and international codes comprise of a brief design procedure of this type of construction. Lot of research is being carried out worldwide about the effect of dynamic loads on these structures. In this paper, FE analysis is done on a designed typical monolithic RC wall panel structure for all zones as per Indian code and the results are compared with different international codal provisions and the formulae presented by Saheb & Desayi and Doh & Fragomeni. This paper consists of background, design and construction of monolithic RC wall panel, FE analysis and comparison of results. © 2013 CAFET-INNOVA TECHNICAL SOCIETY.Item Experimental studies on the effects of corrosion on the flexural strength of RC beams(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2014) Pandit, P.; Venkataramana, K.; BabuNarayan, K.S.; Parla, B.; Kimura, Y.RC structures are generally very durable and are capable of withstanding a variety of adverse environmental conditions. However, failures of these structures still occur and reinforcement corrosion is one of the major causes. In the present research, corroded Ordinary Portland Cement (OPC) beams were tested in the laboratory to evaluate their flexural behavior. Accelerated corrosion technique was adopted to corrode the beams. The corrosion was measured using Applied Corrosion Monitoring (ACM) instrument. From the results, it is seen that, as the rate of corrosion increases, the load carrying capacity decreases. The deflection increases initially and then decreases. It is observed that the stiffness of the beams is reduced when rate of corrosion is increased due to changes in the modulus of elasticity of corroded steel. © 2014 CAFET-INNOVA TECHNICAL SOCIETY.Item Effect of Coir Reinforced Soil on the Seismic Response of RC Framed Buildings(Springer, 2022) Sreya, M.V.; Jayalekshmi, B.R.; Venkataramana, K.This study examines the effectiveness of reinforcing the soil with coir mat, a natural material, to act as a seismic soil-isolation medium. A 3D finite element simulation has been carried out on models of five-storey buildings resting on raft foundations in soft and stiff soil with and without the soil-isolation mechanism. The optimum values of the parameters such as the depth of embedment, width, and thickness of the coir mat have been analyzed. The isolated soil-structure system was exposed to two different earthquake motions, such as El Centro (1940) and simulated seismic excitation corresponds to the elastic design spectrum for Zone III as per the Indian Standard code (IS 1893 (Part 1): 2016). The optimum value for the depth of embedment, width, and thickness of the coir mat was identified as B/18, B/0.45 and B/36. The proposed study also deals with the coir (C) mat composited with other isolation materials such as polyethylene (PE) foam, rubber (RU) mat and geomembrane (G) to form C-PE, C-RU and C-G mats. These composites were proposed to increase the durability of the coir mat. The reinforcement of the C-PE mat shows a maximum of about 30% reduction in roof acceleration and 68% reduction in contact pressure. A pore water pressure analysis of soil bed also has been carried out to study the efficacy of these materials to reduce the excess pore water pressure generated in soil under earthquake loading. For that, a simple soft soil is modelled in Cyclic 1D software with and without the soil-isolation mechanism. The soil bed was exposed to El Centro (1940) and Northridge (1994) input motions. C-PE mat significantly reduces the excess pore water pressure by almost 93% and 88% in soil under El Centro and Northridge input motions, respectively. © 2022, Indian Geotechnical Society.Item Analysing the flexural response of reinforced concrete cantilever beams under the influence of corrosion: an experimental and numerical study(Cogent OA, 2025) Pandit, P.; Venkataramana, K.The main goal of this study is to evaluate how reinforcement corrosion affects the bending strength of cantilever beams made of reinforced concrete. In the experimental phase, the beams underwent corrosion up to 10% using an accelerated corrosion methodology. Applied corrosion monitoring equipment was employed to gauge the corrosion rate accurately. Following that, corroded beams were tested in the laboratory to examine their flexural behavior. Notably, Portland Pozzolana cement beams exhibited greater corrosion resistance compared to ordinary Portland cement beams, attributed to lower chloride migration in PPC beams, resulting in a 15% increase in corrosion resistance. Additionally, finite element analysis was conducted to develop a numerical analytical approach to effectively evaluate the behaviour of reinforced concrete beams. The research findings revealed that the FE model predicted failure loads to be approximately 11% more than experimental values, while deflections were estimated to be 8% lesser than the experimental value, the FEM model more stiffer than experimental values. © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.