Faculty Publications
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Item Mineralogical study of concretes prepared using carbonated flyash as part replacement of cement(Springer, 2019) Sahoo, S.; Das, B.B.Cement production is excessive energy intensive, responsible for depletion of natural layers and high carbon foot print. Thus search for an environmentally benign cement substitute still is an on-going process. Fly ash is a well-established concrete admixture enhancing the strength, durability and micro-structural properties. As well as it is a good reagent to sequester atmospheric carbon dioxide. Concretes prepared through part replacement of cement by carbonated fly ash demonstrate good resistance against chloride, acid and sulfate attack. In the present research mineralogical study of CFC (Carbonated Fly ash concrete) has been conducted through XRD analysis. XRD of control concrete (CC) and fly ash concrete (FC) have also been carried out to study the comparative distributions of mineral crystallites present in concretes. The tests have been conducted in the concrete specimens cured in water for 28 days and 90 days to study the effect of hydration and extent of pozzolanic reaction on the mineralogical composition. Two replacement levels of 25 and 40% were considered for experimentation. The qualitative XRD investigation yielded a higher intensity of CaCO3 in the concretes prepared using Carbonated Fly ash. The presence of CaCO3 helped the concretes in developed chemical resistances dense and improved microstructure. The thermogravimetric analysis further confirmed the presence of higher Carbonates in the CFC specimens. © Springer Nature Singapore Pte Ltd. 2019.Item Use of concrete wastes as the partial replacement of natural fine aggregates in the production of concrete(Springer, 2019) Saha, S.; C, C.; Vinay, K.Due to rapid development of construction industries in various dimensions, demand for construction materials is also gaining high momentum. Therefore, availability of natural sources of construction materials is going to be in decreasing trend to cope up with the high demand. Again currently, quantity of construction and demolition waste is also going too high day by day. Reuse of these construction and demolition waste is one of the promising solutions to protect natural fine aggregates. This study aims at investigations the possibility of the usage of these construction and demolition wastes to produce the fresh concrete with desirable properties. Natural fine aggregates (river sand) are replaced by the recycled fine aggregates by the different percentage levels for the production of fresh concrete. A comparative interpretation on the strength characteristics of the concrete produced with Ordinary Portland Cement and Portland Pozzolana Cement is also presented and discussed in this paper. © Springer Nature Singapore Pte Ltd. 2019.Item Use of foundry sand as partial replacement of natural fine aggregate for the production of concrete(Springer, 2019) Saha, S.; C, C.; More, A.P.The scarcity of natural fine aggregate becomes prominent in the present scenario due to high consumption of natural fine aggregate as the demand for concrete is increasing day by day. As a result, environmental degradation also becomes very significant. In this experimental study, an effort has been made to study the feasibility of using foundry sand as partial replacement for natural fine aggregate to produce concrete with desired properties. Physical and mechanical properties of the produced concrete were studied by incorporating foundry sand, 10, 20, 30, and 40% of the mass of total fine aggregate in the mixes. For achieving the desired strength of concrete mixes, 30% replacement of natural fine aggregates by foundry sand was observed in this work to be considered for the production of fresh concrete. Use of certain percentage of foundry sand as alternative for natural fine aggregate to produce concrete will lead to protect the natural resources, save the environmental system, and promote sustainability in concrete industries. © Springer Nature Singapore Pte Ltd. 2019.Item Durability studies of polypropylene fibre reinforced concrete(Springer, 2019) Srikumar, R.; Das, B.B.; Goudar, S.K.A research programme was initiated to understand the durability of polypropylene fibre reinforced concrete (PFRC). PFRC was prepared with varying dosages of polypropylene fibre. Dosages used were 0.5–1.5% of cement content (by weight) with an interval of 0.5% and was added as a cement replacement to concrete mix. Durability studies were carried out by exposing the 28 days cured cubical specimens into marine environment having different pH levels (1, 4, 7, 10 and 13). The varying pH levels represent the pH of industrial effluents. The marine environment was simulated in the laboratory by adding 3.5% NaCl to the tap water. The specimens were exposed for the durations of 60 and 90 days. The resistance of concrete to marine environment was measured through compressive strength retention and ultimate bond strength retention. Scanning Electron Microscopy (SEM) studies were also carried out to understand the fibre dispersion. Test results show that compressive and bond strength increases with increase in pH and decreases with increase in immersion duration. Concrete with 0.5 and 1% fibre content are more desirable and have given higher residual compressive and residual bond strength when compared to concrete with 1.5% fibre content. © Springer Nature Singapore Pte Ltd. 2019.Item Techniques for preparation and dispersion of nano-SiO2 in Cementitious System—A Review(Springer, 2019) Snehal, K.; Das, B.B.Nowadays, the research in the field of concrete is driving its focus on novel technology by making use of nanosized particles so-called nanotechnology in concrete. The oxide nanoparticles have a great influence on concrete properties, amongst all the nanoparticles, nano-silica is the first nano product that replaced the micro silica or silica fume in concrete, and it is the most predominantly used nanoparticle amid all other nanoparticles in cementitious system. This paper states the overview on various methods involved in production of nano-SiO2 particles for the purpose of utilizing in cementitious system as well as the various techniques for well dispersion of nanosized SiO2 particles in cement matrices. © Springer Nature Singapore Pte Ltd. 2019.Item Experimental and numerical studies on compressive behaviour of CFRP wrapped cylindrical concrete specimens subjected to different pre-loading conditions(Elsevier Ltd, 2020) Sathwik, M.C.; Prashanth, M.H.; Naik, S.C.; Satish, A.Numerous concrete structures have reached the end of their service life, either due to deterioration of the concrete caused by environmental factors or due to being functionally obsolete. Most of them are in serious need for restoration, retrofitting and rehabilitation. Carbon fibre reinforced polymer sheets are well suited for this because of their high strength to weight ratio, good fatigue properties and excellent resistance to corrosion. Their application has been rapidly growing in the civil engineering field and is becoming a promising solution for strengthening the deteriorated structures. Since CFRPs are easy to apply, they minimize labour costs and leads to significant savings in the overall costs of the project. In the present study, concrete specimens were damaged to a different extent by subjecting it to uniaxial compression followed by wrapping with CFRP sheets. Then, the effects of CFRP wrapping on the strength of pre-damaged concrete specimens are studied experimentally. Thereby the behaviour of normal concrete and CFRP wrapped concrete specimens are studied. The experimental results obtained are compared with the numerical results obtained using ABAQUS software. © 2019 Elsevier Ltd. All rights reserved.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 Application of Proper Orthogonal Decomposition in Concrete Performance Appraisal(Springer Science and Business Media Deutschland GmbH, 2021) Manoj, A.; Babu Narayan, K.S.B.Mould ability of concrete has made it the most versatile and popular material of construction. Workability, strength and durability of concrete are very important characteristics that depend on a large number of variables like cement and aggregate type, mix proportioning, method of mixing, conveying, placing and curing and environmental conditions of exposure like temperature, humidity, wind velocity and insolation. The degrees to which workability, strength and durability characteristics vary, and also interplay and conflicts make decision on consideration of independent variables that influence concrete performance, make the job of analysts very complex. Proper Orthogonal Decomposition (POD) is a tool that has great usage potential in reorganizing and rationalizing vast data to understand dependence, interdependence and independence of variables that affect the concrete characteristics. This paper presents the utility of Proper Orthogonal Decomposition in concrete performance appraisal. © 2021, Springer Nature Singapore Pte Ltd.Item Effect of Heating and Fluid Saturation on Certain Physico-Mechanical and Fracturing Behaviour of Concrete(Springer Science and Business Media Deutschland GmbH, 2024) Gafur, I.A.; Anilkumar, A.; Parappalli, A.N.; Srinivasan, V.Understanding the fracturing characteristics of construction materials under varying environmental conditions is very important in considering the safety of infrastructural facilities for sustainable civil structures. Concrete has been extensively used in construction, and with recent advancements in offshore structures, its strength in adverse conditions is pivotal and hence requires significant attention. This study investigates the variation in the mechanical properties and fracturing behaviour of M25 concrete cubes under different environmental conditions. The cubes were subjected to five different conditions: heating, saturation, and a combination of heating and saturation. Saturation was carried out separately using water and brine solutions. Three cubes were cast for each condition. The physical properties included density and Ultrasonic pulse velocity, followed by mechanical testing for strength. Acoustic emission monitoring was carried out simultaneously along the mechanical testing. Acoustic emission techniques are used to visualize fracturing behaviour of concrete cubes. Fracture thresholds are established to find crack closure and elastic region, and regions of stable crack propagation and unstable crack propagation. The results show that the combination of heating and fluid saturation significantly impacts the physico-mechanical properties of concrete, reducing its compressive strength and increasing its susceptibility to fracture. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Gamma radiation shielding characteristics of concrete mixes-the state of art(2013) Santhoshkumar, M.; Narasimhan, M.C.; Karkera, B.In this paper, initially the interaction of gamma radiation with materials in general and concrete in particular are discussed. The state-of-art attempts made in different parts of the world, in improving the gamma radiation shielding properties by incorporating alternate/additional ingredients in concrete mixes are discussed. Such incorporation may be in terms of changes in any of the binder, coarse or fine aggregate components of the concrete mixes. The usage of materials such as mineral admixtures, high density solid wastes and fibres is also reported. The possible use of other mineral materials in concrete mixes for enhanced shielding performance against gamma radiation in nuclear installations is brought out. A brief review of the mix design parameters controlling shielding performance of concrete mixes is also cited. An attempt has been made to compare the shielding performances of different concretes by comparing their linear attenuation co-efficient values (μ) reported in the literature. In view of the exponential surge in γ-ray sources in nuclear industry this review is relevant to save the planet earth from an impending global disaster as well as introducing radiation in industries, food preservation, nuclear medicine and many other such applications. © 2013 CAFET-INNOVA TECHNICAL SOCIETY.