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Author: search.filters.author.Yaragal, S.C.Subject: search.filters.subject.Compressive strength

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    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.
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    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.
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    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.
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    Studies on concrete cylinders subjected to elevated temperatures
    (2010) Babu Narayan, K.S.; Anil Kumar, G.; Chandrakala, C.; Shashikumar, H.M.; Venkataramana, K.; Yaragal, S.C.; Chinnagiri Gowda, H.C.; Reddy, G.R.; Sharma, A.
    Concrete is a poor conductor of heat, but can suffer considerable damage when exposed to fire. Concrete in structures is likely to be exposed to high temperatures during fire. The relative properties of concrete after such an exposure are of great importance in terms of the serviceability of buildings. Unraveling the heating history of concrete is important to forensic research or to determine whether a fire exposed concrete structures and its components are still structurally sound or not. Assessment of fire damage concrete structures usually starts with visual observation of color change, cracking and spalling. On heating, a change in color from normal to pink is often observed and this is useful since it coincides with the onset of significant loss of concrete strength. This work reports the characteristics of concrete at elevated temperatures. Popular normal strength grades (M20, M25, M30, M35, M40 and M45) produced by Ready Mix Concrete (RMC) India, Mangalore have been used in production of test specimens (150 mm diameter and 300mm height cylinders) to obtain more meaningful and realistic data. In the preliminary phase 150 mm diameter and 300mm height cylinders were cast, cured and tested by destructive method for gathering data on strength characteristics. Later these test samples were subjected to elevated temperatures ranging from 100°C to 800°C, in steps of 100°C with a retention period of 2 hours. After exposure, weight losses were determined and then again destructive tests were conducted to estimate the residual split tensile strength. Test results indicated that weight and strength significantly reduces with an increase in temperature. © 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.
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    Strength retention characteristics of concrete cubes subjected to elevated temperatures
    (2010) Yaragal, S.C.; Clarke, K.S.; Mahesh Babu, K.; Ashokumar, S.; Venkataramana, K.; Babu Narayan, K.S.; Chinnagiri Gowda, H.C.; Reddy, G.R.; Sharma, A.
    Concrete in structures is likely to be exposed to high temperatures during fire. The relative properties of concrete after such an exposure are of great importance in terms of the serviceability of buildings. The probability of its exposure to elevated temperatures is high due to natural hazards, accidents and sabotages. Therefore, the performance of concrete during and after exposure to elevated temperature is a subject of great interest to the designer. Physical changes like cracking, colour change, spalling and chemical changes like decomposition of Ca(OH)2 and the C-S-H gel take place when subjected to elevated temperatures. This work reports the characteristics of concrete at elevated temperatures. Popular normal strength grades (M20, M25, M30, M35, M40 and M45) produced by Ready Mix Concrete (RMC) India, Mangalore have been used in production of test specimens (150 mm cubes) to obtain more meaningful and realistic data. In the preliminary phase 150 mm cubes were cast, cured and tested by destructive method for gathering data on strength characteristics. Later these test samples were subjected to elevated temperatures ranging from 100°C to 800°C, in steps of 100°C with a retention period of 2 hours. After exposure, weight losses were determined and then again destructive tests were conducted to estimate the residual compressive strength. Test results indicated that weight and strength significantly reduces with an increase in temperature. © 2010 CAFET-INNOVA TECHNICAL SOCIETY.
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    Studies on normal strength concrete cubes subjected to elevated temperatures
    (2010) Yaragal, S.C.; Babu Narayan, K.S.; Venkataramana, K.; Kulkarni, K.S.; Gowda, H.C.C.; Reddy, G.R.; Sharma, A.
    Concrete in structures is likely to be exposed to high temperatures during fire. The probability of its exposure to elevated temperatures is high due to natural hazards, accidents and sabotages. Therefore, the performance of concrete during and after exposure to elevated temperature is a subject of great importance and interest to the designer. Popular normal strength grades of concrete produced by Ready Mix Concrete (RMC) India, Mangalore have been used in production of test specimens (150 mm cubes), cured and tested by destructive method for gathering data on strength characteristics. Later, these test samples were subjected to elevated temperatures ranging from 100 C to 800 C, in steps of 100 C with a retention period of 2 hours. After exposure, weight losses and the residual compressive strength retention characteristics are studied. Test results indicated that weight and strength significantly reduces with an increase in temperature. Residual compressive strength prediction equations are proposed for normal strength concretes subjected to elevated temperatures.
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    Characteristics of normal strength concrete with and without chemical admixtures at elevated temperatures
    (CAFET INNOVA Technical Society 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2011) Yaragal, S.C.; Warad, S.A.; Babu Narayan, K.S.; Venkataramana, K.
    Fire is one of the most destructive powers to which a building structure can be subjected. Behavior of concrete when exposed to fire in cases like nuclear plants, cooling towers or any accidental fire in industrial buildings, is a serious concern, on the strength retention property of concrete. This work reports strength retention studies on compressive and split tensile strength of normal concrete with and without the chemical admixture (Reobuild 918, BASF make) at elevated temperatures. Concrete cubes of size 100 mm have been cast as per prior mix design for M30 grade of concrete, 28 days water cured and tested by destructive method for strength before exposure. Later these specimen were subjected to elevated temperatures of 200°C, 400°C, 600°C and 800°C with a retention period of 2 hours and were allowed cool within the furnace to reach ambient temperature. Later their appearance, colour and cracks were observed and also weight losses were determined. Further, destructive tests were conducted to estimate residual compressive and residual split tensile strengths and prediction equations are proposed to ascertain splitting tensile strengths from compressive strengths. © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.
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    Effect of recuring on compressive strength of thermally deteriorated concrete cubes
    (2011) Prasanth, S.; Yaragal, S.C.; Babu Narayan, K.S.
    Concrete is found to undergo degradation when subjected to elevated temperatures during an event such as fire and lose substantial amount of its strength. The loss of strength in concrete is mainly attributed to decomposition of C-S-H and release of chemically bound water, which begins when the exposure temperature exceeds 500°C. When thermally deteriorated concrete is supplied with water there is a substantive gain in strength as a consequence of rehydration of cement that is initiated. This paper presents results of an experimental program carried out to investigate the effect of recuring on strength gain of normal strength concrete specimens subjected to elevated temperatures from 500°C to 800°C, which were subjected to retention time of two hours at the designated temperatures. © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.
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    Usage potential of melt processed plastic pellets as a substitute to fine aggregate in porous concretes
    (2012) Maneeth, P.D.; Lokesh, G.; Yaragal, S.C.; Babu Narayan, K.S.
    Porous concrete (PC) has been used for over 30 years. Because of its high porosity, the most common usages have been in the area of storm water management, but have been limited to use in pavements with low volume traffic, because of its low compressive strength compared to conventional concrete. Domestic and industrial plastic waste management has posed a serious challenge to engineers and scientists today. In this study an attempt is made to utilize plastic waste (melt processed) from small industries as a substitute for fine aggregate (up to 10%) in producing porous concretes. The recycled plastic (melt processed) was produced by drawing industrial and domestic waste plastic into long strands which were cut to small pieces forming granules. The plastic granules (pellets) are used as substitute to sand in this investigation. This experimental investigation reports the scope for plastic waste utilization as a substitute for fine aggregate and its influence on properties like porosity, permeability, compressive strength and tensile strength of porous concretes. © 2012 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.
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    Strength characteristics of concrete exposed to elevated temperatures and cooled under different regimes
    (2012) Yaragal, S.C.; Babu Narayan, K.S.; Adari, S.
    Concrete loses strength in the event of accidental fires. The residual strength of normal strength concrete is of vital importance for ascertaining serviceability of buildings after the event of fires. Strength loss in concrete is dependent on the temperature of exposure, its duration and the way it gets cooled. In this study concrete cubes of size 100 mm have been cast for M25 grade of concrete, 28 days water cured. The specimens were subjected to elevated temperatures of 150°C, 250°C, 350°C, 450°C and 550°C with a retention period of 1 hour. After 1 hour of exposure, specimens were allowed to cool under different cooling regimes to ambient temperature. Later their appearance, colour and cracks were observed and also weight losses were determined. Further, destructive tests were conducted to estimate residual compressive and split tensile strengths. Important performance changes have been presented and discussed. Split tensile strengths are related to compressive strengths for all the cases of cooling regimes.