Faculty Publications
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Item Experimental investigation on utilization of waste shredded rubber tire as a replacement to fine aggregate in concrete(Springer, 2019) Hiremath, P.N.; Jayakesh, K.; Rai, R.; Naganna, N.S.; Yaragal, S.C.Depletion of natural resources in the past few decades due to rapid construction activities all around the world has forced a threat to the availability of natural resources for future generation. The utilization of waste industrial by products, in the form of supplementary cementitious materials and waste tire rubber products replacing natural aggregates in production of concrete. In the present study performance of concrete mixes incorporating 2.5, 5, 7.5 and 10% Waste Shredded Rubber Tire (WSRT) as partial replacement of fine aggregate is investigated. Numerous research works have been conducted on replacement of aggregate by waste crumb rubber but data scarce on utilization of waste rubber in concrete directly. Hence to examine characteristics of shredded rubber tire based concretes, two sets of concrete specimen were produced. In the first set, shredded rubber tire is added directly without any pretreatment and in the second set the shredded rubber tire was immersed in NaOH solution for 24 h and then washed with water thoroughly and rubbed with sand paper to obtain the rough surface finish to facilitate improved bonding properties with cement matrix. To evaluate the performance of WSRT based concretes, fresh and hardened properties were determined by conducting slump tests on fresh mixes, and compression, flexural and impact tests on hardened concrete cubes and prisms. Proving results were obtained for potential use of WSRT in concretes for generalized applications. © Springer Nature Singapore Pte Ltd. 2019.Item Strength characteristics of laterized mortars using processed laterite(Springer, 2019) Basavana Gowda, S.N.; C, C.; Yaragal, S.C.The rapid pace of population growth in India has enforced the construction industry to use construction materials at an accelerated rate leads to the exhaustion of natural resources. Large-scale constructions have a severe influence on the environment instigating many threats either directly or indirectly like exhaustion of the river due to unscientific sand mining being done at a frightening level, etc. To address this issue, it is required to find substitutes for river sand for producing mortars. One among the locally available marginal resource is laterite. In this study, an attempt is made to study the performance of cement mortars using laterite as fine aggregate in replacement levels of 0, 25, 50, 75 and 100% to natural fine aggregates (river sand). Studies were carried out in two stages, initially river sand is replaced with laterite quarry waste (unprocessed laterite), and then it is replaced with the processed laterite. The flowability and compressive strength characteristics of mortars are studied. Results indicate that, the decrease in compressive strength of mortars with increase in replacement levels of river sand by unprocessed laterite was more, when compared to mortars with processed laterite. However, there is only 13% reduction in strength for laterized mortar with 100% processed laterite when compared to control mortar is observed. © Springer Nature Singapore Pte Ltd. 2019.Item Shape optimization and assessment of wind induced stresses in domes(2009) Babu Narayan, K.S.; Yaragal, S.C.; Tamura, Y.Domes are popularly used for column free areas. They are employed as covers to reservoirs and treatment units and also as containment in nuclear reactors. Inverted domes are popular as foundations. This paper demonstrates the need and scope for optimization of domes by formulating and solving the problem by use of calculus. A simple but elegant method is suggested for determination of wind stresses by statics which compares very well with that obtained by rigorous method.Item Microphone based static pressure probe measurements in two dimensional fluid flows(Research Publishing Services editorial@rpsonline.com.sg, 2013) Yaragal, S.C.Wind tunnel experiments were conducted on two dimensional flow field downstream of a normal plate/splitter plate combination. The effect of varied level of perforation of the normal plate on fluctuating pressures measured across and along the separation bubble was studied using microphone based static pressure probe. The normal plate perforation levels used were 0%, 10%, 20%, 30% and 40%. The Reynolds number based on step height was varied from 4 × 103 to 1.2 × 104. The analysis of the results show that the maximum fluctuating pressure coefficient in the flow field, base pressure coefficient and the perforation level can be well correlated, for the cases studied. © © 2013 APCWE-VIII. All rights reserved. Published by Research Publishing, Singapore.Item Investigation on Mechanical Properties of Reactive Powder Concrete under Different Curing Regimes(Elsevier Ltd, 2017) Hiremath, P.N.; Yaragal, S.C.Reactive Powder Concrete (RPC) is a form of Ultra High Performance Concrete (UHPC). The main constituents of RPC are cement, sand, silica fume, steel fiber and quartz powder with minimal water to binder ratio, without coarse aggregate. Due to its dense microstructure, RPC exhibit superior properties such as higher strength, durability and long term stability. Earlier researchers have produced RPC with Compressive strength up to 800 MPa and flexural strength of 75 MPa. In the present study, locally available materials are used to produce RPC of different mix proportions. The main objective is to study the effect of different curing regimes on the strength of RPC. The durability study is also carried out by way of accelerated corrosion test and acid test. Results have shown considerable enhancement in compressive strength when RPC specimen were subjected to hot air curing of different durations. RPC specimen cured under hot air curing and steam curing shown better performance compared to normal curing and air curing. Also RPC has shown better resistance to sulphate attack; further the rate of corrosion is low compared to high performance concrete. © 2017 Elsevier Ltd.Item Significance of processing laterite on strength characteristics of laterized concrete(Institute of Physics Publishing helen.craven@iop.org, 2018) Basavana Gowda, S.N.; C, C.; Yaragal, S.C.The boom in infrastructure development has resulted in acute shortage of river sand. To address this issue, it is required to find substitutes for river sand for producing concrete. One among the locally available marginal resource is laterite. In this study, an attempt is made to study the performance of cement concrete using laterite as fine aggregate in replacement levels of 25, 50, 75 and 100% to natural fine aggregates (river sand). Studies were carried out in two stages, initially river sand is replaced with laterite quarry waste (unprocessed laterite), and then it is replaced with the processed laterite. The workability and compressive strength characteristics of concrete are studied. Results indicate that, the decrease in compressive strength of concrete with increase in replacement levels of river sand by unprocessed laterite was more, compared to concrete with processed laterite. However, there is only 7% reduction in strength for laterized concrete with 100% processed laterite compared to control concrete. Microstructure studies were also conducted to understand the morphology of river sand and laterite particles with the cement matrix using scanning electron microscope. © Published under licence by IOP Publishing Ltd.Item Performance of Recycled Coarse Aggregate Concretes with Basalt Fibers at Elevated Temperatures(Springer Science and Business Media Deutschland GmbH, 2022) Yaragal, S.C.; Hiremath, P.N.; Kalyan, M.M.; Kumar, D.; Shiji, P.P.The utilization of Construction and Demolition waste (C&D) is gaining importance due to rapid depletion of natural aggregates, as well as due to increased awareness worldwide towards sustainable development. Water absorption characteristics of adhered mortar associated with C&D aggregates has to an extent hindered the potential of extensively using Recycled Coarse Aggregate (RCA) in concretes. The study examines the performance of concretes with replacement of natural coarse aggregates by RCA in different proportions. Attempts were made to enhance the compressive strength of RCA based concretes using basalt fibers. Results, show that possibility of using RCA based concretes (either 50 or 100% replacement) is possible without compromising strength, by incorporating 1.5% basalt fibers. Use of basalt fibers result in 13 and 19% enhanced strengths to concretes (for 50 and 100% replacement) apart from exhibiting superior elevated temperature endurance. Study also includes microstructural investigation of RCA based concretes with and without basalt fibers at elevated temperatures. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Environmental sustainability of waste glass as a valuable construction material - A critical review(EM International rktem@pn3.vsnl.net.in, 2018) Sudharsan, N.; Palanisamy, T.; Yaragal, S.C.The increased demand for concrete as a construction material leads to increase in cement production. The formulation of cement, emits a significant amount of CO2 to the atmosphere, which causes severe environmental pollution. Many efforts are being made to reduce the use of Portland cement in concrete to avoid environmental issues. These efforts mainly involve the utilization of value added materials in concrete. In this context, the waste glass powder has excellent pozzolanic properties, to use glass powder as a supplementary cementitious material in concrete. The use of waste glass powder in concrete has many economic and environmental benefits. This paper summarizes the literature regarding the utilization of waste glass powder as a supplementary cementitious material in mortar and concrete. © 2018 EM International. All rights reserved.Item The wind tunnel experiments were conducted over a solid/perforated plate with a long splitter plate in its plane of symmetry. The effect of varied level of perforation of the normal plate on the behaviour of two dimensional separation bubble was studied. The mean velocity and surface mean pressure distributions were also measured after preliminary flow visualization studies. The normal plate perforation levels used are 0%, 10%, 20%, 30%, 40% and 50%. The Reynolds number based on step height was varied from 4 × 103 to 1.2 × 104. Mean pressures were found to be strongly dependent on perforation level of the normal plate. The shape and size of the bubble vary with different perforated normal plate that is to say, the bubble gels reduced both in height and length upto 30% perforation level. For higher perforation of the normal plate, the bubble is completely swept out. © 2002 Taylor & Francis Group, LLC.(An experimental investigation of mean flow field behind perforated plates on a flat surface) Yaragal, S.C.; Govind Ram, H.S.; Murthy, K.K.2002