Faculty Publications
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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 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 Effect of various additives on the properties of fly ash based geopolymer mortar(Springer, 2019) Mustafa, R.; Shivaprasad, K.N.; Das, B.B.In the present study, setting time and variation in strength of fly ash based geopolymer mortar prepared from natural sand as fine aggregates. Blast furnace slag (GGBS), micro silica and lime dust used as additives to fly ash based geopolymer mortar at 5, 10 and 15% of weight of fly ash. Alkaline activator used in the present study is combination of sodium silicate solution and sodium hydroxide solution. Concentration of sodium hydroxide solution was maintained 10 M and sodium silicate to sodium hydroxide ratio was fixed as 2.5:1 by weight. From the test results, it is observed that setting time and compressive strength geopolymer samples were significantly influenced by the type of additive added in the preparation of the geopolymer mortar. © Springer Nature Singapore Pte Ltd. 2019.Item An experimental investigation to determine the properties of fly ash based geopolymers as per indian standards(Springer, 2019) Saha, S.; C, C.Production of ordinary Portland cement requires huge quantity of natural resources and also releases huge quantity of carbon dioxide into the atmosphere. Research efforts have been continuing to establish geopolymer as an alternative cementitious material for the replacement of ordinary Portland cement. This paper presents the study to find out the properties of fly ash based geopolymer paste and 28 days compressive strength of geopolymer mortar. Standard consistency, setting time of geopolymer paste has been determined using vicat’s apparatus (according to Indian Standards), which is followed for cement paste, varying the concentration of sodium hydroxide solution from 6 to 16 M. Results indicate higher standard consistency, more time required for setting for fly ash based geopolymer than that of cement paste. Compressive strength of the geopolymer paste and mortar 17 specimens increases with the increase of the concentration of sodium hydroxide solution and decrease beyond 14 M. © 2019, Springer Nature Singapore Pte Ltd.Item Strength Behavior of Rammed Earth Stabilized with Metakaolin(Springer, 2020) Thiviya, S.K.; Krishnan, A.G.; Kalathuru, M.; Sharma, A.K.; Kolathayar, S.Rammed earth is an ancient construction technique practiced in India and in other parts of the world. The ancient traditional technique was of the un-stabilized method but incorporating suitable stabilizing materials will improve the strength of rammed earth construction. The main objective of the present study is to assess the behavior of the rammed earth with metakaolin. The suitability of the soil was tested based on sieve analysis and followed by mini compaction tests; optimum moisture content for the rammed earth construction for the selected soil was fixed for different proportions of binders with the soil. From the compaction results, the binder content was fixed for stabilization of rammed earth. The unconfined compressive strength of the sample was found for the samples at 7, 14, 28 days of curing, and microstructural studies of the samples were performed. The compression strength of rammed earth cubes was tested and also the durability of the cubes was determined by the spray erosion test. © 2020, Springer Nature Singapore Pte Ltd.Item Fast Setting Steel Fibre Geopolymer Mortar Cured Under Ambient Temperature(Springer, 2021) Prasanna, K.M.; Theodose, I.; Shivaprasad, K.N.; Das, B.B.Cement and cementitious materials are being used worldwide as the most popular multipurpose construction materials but the greenhouse gas such as carbon dioxide (CO2) produced during its manufacturing process creating a huge environmental hazard, thus efforts have been made for alternative binders. Geopolymer binder is new age binder alternative to ordinary Portland cement in infrastructure projects because it is produced from eco-friendly and industrial waste materials. This study was aimed to produce fast setting with ground-granulated blast-furnace slag (GGBS) in fly ash-based geopolymer mortar incorporated with steel fibres cured under ambient temperature. In this research, alkaline to binder ratio was varied from 0.5 to 0.8, crimped steel fibre are varied from 0.5 to 1.5% by total volume of binder and combination of fly ash (FA) and GGBS (100%:0%, 90%:10%, 80%:20%, 70%:30%, 60%:40% and 50%:50%) as binder were used for preparation of fibre geopolymer mortar. The tests conducted include stetting time and flowability of geopolymer mortar, compressive strength and microstructural characterisation of steel fibre geopolymer mortar. The tests for compressive strength were carried out on standard size of mortar samples at curing period of 3, 7 and 28 days. It is noted from the test results that increase in GGBS content setting times were decreased; however, the compressive strength of fly ash-based geopolymer mortar increased. The highest compressive strength at 28 days of curing period was found to be 69.5 MPa, which is obtained with content of 1% of steel fibres and alkaline to binder ratio of 0.6 with 50%:50% binder’s proportions. Further, it is observed that the incorporation of steel fibres in plain geopolymer mortar have enhanced the compressive strength and optimum dosage of fibres was found to be 1%. © 2021, Springer Nature Singapore Pte Ltd.Item A Review on Mechanical and Microstructure Properties of Reinforced Concrete Exposed to High Temperatures(Springer, 2021) Goudar, S.K.; Santhosh, S.K.; Das, B.B.This paper presents the recent research progress on the response of concrete exposed to fire or high temperatures. The main highlight of this review paper is a compilation of previously reported data regarding the variations in mechanical properties and microstructure properties of concrete when exposed to high temperatures. The concrete structures get deteriorated at the macro- and microscopic levels due to high-temperature exposure. The macro-level damages can be measured with degradation in mechanical properties such as the reduction in compressive strength, weight loss, changes in elastic properties, reduction of bond strength in reinforced concrete, etc. The macro-cracks on the surface of concrete causes spalling which can be observed after exposing the concrete samples to more than 300 ℃. The compressive strength of the concrete reduces slightly till 400 ℃, and when the temperature increased to 600 ℃, there was an exponential reduction in the compressive strength of concrete. Another important parameter is bond strength degradation, which plays a crucial role in durability issues. To understand the deterioration phenomenon and changes in mechanical properties, the changes at the level of the microstructure of concrete need to be understood. Dehydration of products causes deterioration of mechanical properties and weight loss of concrete when exposed to high temperatures. At different temperatures, the microstructure changes and the response of hydration products such as calcium hydroxide (CH), CSH gel, unhydrated cement and capillary water reported by previous researchers are compiled and discussed. © 2021, Springer Nature Singapore Pte Ltd.Item Effect of waste ceramic tiles as a partial replacement of aggregates in concrete(Elsevier Ltd, 2019) Bommisetty, J.; Sai Keertan, T.S.; Ravitheja, A.; Mahendra, K.In recent constructions, the consumption of ceramic materials is increasing day by day in the form of tiles, sanitary fittings, electrical insulators etc. But a large quantity of ceramic materials changes into wastage during processing, transporting and fixing due to its brittle nature. Therefore, using these wastes in concrete production could be an effective measure in maintaining the environment and improving the properties of concrete. Hence, the crushed waste ceramic tiles were used in concrete as a replacement for natural coarse aggregates with 0%, 5%, 10%, 15% 20% and 25% of substitution. After analyzing results, the optimum value of waste ceramic tile to be used within the concrete mix with a water/cement ratio of 0.5 was determined as about 20%. The findings revealed that using waste ceramic tile lead to enhancing the properties of concrete. © 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 1st International Conference on Manufacturing, Material Science and Engineering.Item Physico-mechanical properties of concrete with industrial waste-A case study(Avestia Publishing info@avestia.com, 2019) Gayana, B.C.; Shashanka, M.; Rao, A.N.; Ram Chandar, K.A few waste materials, such as demolition waste, steel slag, quarry dust, fly ash are dumped in landfills. This causes environmental issues and pollution. The present study aims to examine the effect of replacing two types of waste materials i.e., quarry dust and steel slag as partial replacement of cement and sand respectively. Cement was replaced partially with quarry dust between 5 to 20% with 5% intervals and sand was replaced by 75% steel slag consistently for all the concrete mixes. The concrete cubes, beams and cylinders were tested for their strength characteristics by measuring compressive strength, flexural strength and splitting tensile strength. The maximum increase of 4%, 34% and 38% in compressive, flexural and splitting tensile strength respectively was observed with 15% quarry dust replaced with cement and 75% steel slag replaced with sand. Based on the present experimental study, partial replacement of these waste materials shall mitigate the issues occurring due to storage and also by utilizing these materials in concrete as replacement for cement and sand resulting in higher strength properties compared to the naturally available construction materials. © 2019, Avestia Publishing.