The Experts below are selected from a list of 645 Experts worldwide ranked by ideXlab platform
Ramazan Demirboga - One of the best experts on this subject based on the ideXlab platform.
-
fire resistance of geopolymer concrete produced from elazig Ferrochrome slag
Fire and Materials, 2016Co-Authors: Ibrahim Turkme, Mehmet Burhan Karakoc, Muslum Murat Maras, Fatih Kantarci, Ramazan DemirbogaAbstract:Summary This paper presents the effect of elevated temperatures up to 700 °C on compressive strength and water absorption of two alkali-activated aluminosilicate composites (one of them is river sand aggregate geopolymer concrete; the other one is crushed sand aggregate geopolymer concrete) and ordinary Portland cement based concretes. To obtain binding geopolymer material, Elazig Ferrochrome slag was ground as fine as cement, and then it was alkali activated with chemical (NaOH and Na2SiO3). Geopolymer concrete samples were produced by mixing this binding geopolymer material with aggregates. At each target temperature, concrete samples were exposed to fire for the duration of 1 h. Fire resistance and water absorption of geopolymer and ordinary Portland cement concrete samples were determined experimentally. Experimental results indicated that compressive strength of geopolymer concrete samples increased at 100 °C and 300 °C temperatures when compared with unexposed samples. In geopolymer concrete samples, the highest compressive strength was obtained from river aggregates ones at 300 °C with 37.06 MPa. Water absorption of geopolymer concrete samples increased at 700 °C temperature when compared with unexposed samples. However, a slight decrease in water absorption of concrete samples was observed up to 300 °C when compared with unexposed samples. SEM and X-ray diffraction tests were also carried out to investigate microstructure and mineralogical changes during thermal exposure. Copyright © 2016 John Wiley & Sons, Ltd.
-
sulfate resistance of Ferrochrome slag based geopolymer concrete
Ceramics International, 2016Co-Authors: Mehmet Burhan Karakoc, Muslum Murat Maras, Fatih Kantarci, Ramazan Demirboga, Ibrahim TurkmeAbstract:This paper presents the study of the performance of a new geopolymer binding material exposed to sulfate attack. Geopolymer binding material was obtained by alkaline activating FS with chemical materials (NaOH and Na2SiO3). Geopolymer concrete samples were produced by mixing this binding material with river sand and crushed sand aggregates. Test specimens were immersed in magnesium sulfate solutions (by weight 3%, 5% and 7%) for various periods of time and the durability of geopolymer concrete was investigated. The residual compressive strength (90 and 180 days), change in weight and length of samples, pH variation of solution and visual appearance of these samples were obtained experimentally. It was concluded that compressive strength of both geopolymer and Ordinary Portland Cement (OPC) based concrete samples decreases with increasing in MgSO4 content and exposure duration. After exposed to 7% MgSO4 solution for 180 days, the minimum decrease in compressive strength was seen 25% in geopolymer concrete samples with crushed sand aggregates.
-
mechanical properties and setting time of Ferrochrome slag based geopolymer paste and mortar
Construction and Building Materials, 2014Co-Authors: Mehmet Burhan Karakoc, Muslum Murat Maras, Ibrahim Turkmen, Fatih Kantarci, Ramazan Demirboga, Ugur M ToprakAbstract:Abstract Many researches have been done to investigate using raw materials in the production of geopolymer cements. This paper presents the effects of alkali dosage and silica modulus when using sodium metasilicate solution at different curing conditions on the geopolymerization of Ferrochrome slag (FS). As alkali activation for geopolymerization, NaOH and Na2SiO3 solution were used. Geopolymer cement was produced using FS as raw material with 3 different silica modulus (0.50, 0.60 and 0.70) and 4 different Na2O concentrations (4%, 7%, 10% and 12%). The setting time, hydration heat and compressive strength of geopolymer paste samples and compressive strength of geopolymer mortar samples were obtained. The setting time varied between 120 and 870 min, it showed variability depending on Na2O content. The highest 28 day compressive strength of the geopolymer paste samples was obtained from one with Na2O concentration of 7% and silica modulus of 0.70. Geopolymer mortars were prepared for the determination of compressive strength by adding FS:sand:alkali activator ratio 1:2:0.30, 0.35 and 0.40. The specimens were cured at 60 °C and 80 °C kept for 20 h and the other mortar samples were stored under laboratory conditions. Compressive strength of the material decreased, when w/b (water/binder) ratio increased. The highest 28 day strength of the geopolymer mortar was obtained at 0.30 w/b ratio and laboratory temperature curing conditions. The hydration heat of geopolymer paste samples was found to be less than normal Portland cements. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were investigated to study the microstructural properties of the geopolymers.
Mehmet Burhan Karakoc - One of the best experts on this subject based on the ideXlab platform.
-
fire resistance of geopolymer concrete produced from elazig Ferrochrome slag
Fire and Materials, 2016Co-Authors: Ibrahim Turkme, Mehmet Burhan Karakoc, Muslum Murat Maras, Fatih Kantarci, Ramazan DemirbogaAbstract:Summary This paper presents the effect of elevated temperatures up to 700 °C on compressive strength and water absorption of two alkali-activated aluminosilicate composites (one of them is river sand aggregate geopolymer concrete; the other one is crushed sand aggregate geopolymer concrete) and ordinary Portland cement based concretes. To obtain binding geopolymer material, Elazig Ferrochrome slag was ground as fine as cement, and then it was alkali activated with chemical (NaOH and Na2SiO3). Geopolymer concrete samples were produced by mixing this binding geopolymer material with aggregates. At each target temperature, concrete samples were exposed to fire for the duration of 1 h. Fire resistance and water absorption of geopolymer and ordinary Portland cement concrete samples were determined experimentally. Experimental results indicated that compressive strength of geopolymer concrete samples increased at 100 °C and 300 °C temperatures when compared with unexposed samples. In geopolymer concrete samples, the highest compressive strength was obtained from river aggregates ones at 300 °C with 37.06 MPa. Water absorption of geopolymer concrete samples increased at 700 °C temperature when compared with unexposed samples. However, a slight decrease in water absorption of concrete samples was observed up to 300 °C when compared with unexposed samples. SEM and X-ray diffraction tests were also carried out to investigate microstructure and mineralogical changes during thermal exposure. Copyright © 2016 John Wiley & Sons, Ltd.
-
sulfate resistance of Ferrochrome slag based geopolymer concrete
Ceramics International, 2016Co-Authors: Mehmet Burhan Karakoc, Muslum Murat Maras, Fatih Kantarci, Ramazan Demirboga, Ibrahim TurkmeAbstract:This paper presents the study of the performance of a new geopolymer binding material exposed to sulfate attack. Geopolymer binding material was obtained by alkaline activating FS with chemical materials (NaOH and Na2SiO3). Geopolymer concrete samples were produced by mixing this binding material with river sand and crushed sand aggregates. Test specimens were immersed in magnesium sulfate solutions (by weight 3%, 5% and 7%) for various periods of time and the durability of geopolymer concrete was investigated. The residual compressive strength (90 and 180 days), change in weight and length of samples, pH variation of solution and visual appearance of these samples were obtained experimentally. It was concluded that compressive strength of both geopolymer and Ordinary Portland Cement (OPC) based concrete samples decreases with increasing in MgSO4 content and exposure duration. After exposed to 7% MgSO4 solution for 180 days, the minimum decrease in compressive strength was seen 25% in geopolymer concrete samples with crushed sand aggregates.
-
mechanical properties and setting time of Ferrochrome slag based geopolymer paste and mortar
Construction and Building Materials, 2014Co-Authors: Mehmet Burhan Karakoc, Muslum Murat Maras, Ibrahim Turkmen, Fatih Kantarci, Ramazan Demirboga, Ugur M ToprakAbstract:Abstract Many researches have been done to investigate using raw materials in the production of geopolymer cements. This paper presents the effects of alkali dosage and silica modulus when using sodium metasilicate solution at different curing conditions on the geopolymerization of Ferrochrome slag (FS). As alkali activation for geopolymerization, NaOH and Na2SiO3 solution were used. Geopolymer cement was produced using FS as raw material with 3 different silica modulus (0.50, 0.60 and 0.70) and 4 different Na2O concentrations (4%, 7%, 10% and 12%). The setting time, hydration heat and compressive strength of geopolymer paste samples and compressive strength of geopolymer mortar samples were obtained. The setting time varied between 120 and 870 min, it showed variability depending on Na2O content. The highest 28 day compressive strength of the geopolymer paste samples was obtained from one with Na2O concentration of 7% and silica modulus of 0.70. Geopolymer mortars were prepared for the determination of compressive strength by adding FS:sand:alkali activator ratio 1:2:0.30, 0.35 and 0.40. The specimens were cured at 60 °C and 80 °C kept for 20 h and the other mortar samples were stored under laboratory conditions. Compressive strength of the material decreased, when w/b (water/binder) ratio increased. The highest 28 day strength of the geopolymer mortar was obtained at 0.30 w/b ratio and laboratory temperature curing conditions. The hydration heat of geopolymer paste samples was found to be less than normal Portland cements. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were investigated to study the microstructural properties of the geopolymers.
Sanjaya Kuma Patro - One of the best experts on this subject based on the ideXlab platform.
-
synthesis and characterization of a new class of geopolymer binder utilizing Ferrochrome ash fca for sustainable industrial waste management
Materials Today: Proceedings, 2020Co-Authors: Jyotirmoy Mishra, Shaswat Kuma Das, R S Krishna, Haradwaj Nanda, Sanjaya Kuma Patro, Syed Mohammed MustakimAbstract:Abstract Sustainable use of industrial wastes for the production of new age eco-friendly construction materials can effectively solve the growing environmental concern over landfills and also provide an integrative industrial waste management strategy. Geopolymers are comparatively a new class of aluminosilicate inorganic polymer which has gained wide recognition due to its remarkable physicochemical and mechanical properties. Various industrial wastes such as fly ash, slag, rice husk ash, Ferrochrome ash, etc. rich in alumina and silica can serve as suitable precursors for the production of geopolymer binders. This paper presents the experimental investigations on the utilization of Ferrochrome ash (FCA), and waste from the Ferrochrome industry as a primary precursor having considerable amounts of alumina, silica, magnesium oxide, potassium oxide for preparation of geopolymer concrete having partial replacements of ground granulated blast furnace slag and lime. The fresh and hardened geopolymer concrete properties: workability and compressive strength are thoroughly investigated. The particle size distribution, the chemical composition, mineralogy, microstructure of binder particles were analysed with advanced analytical techniques such as XRF, PSA, XRD, SEM/EDS. The results of this study not only suggest the effective utilization of Ferrochrome ash for the synthesis of a new class of geopolymer binders but also provide a sustainable route for the management of Ferrochrome waste currently generated in various countries worldwide.
-
strength sorption and abrasion characteristics of concrete using Ferrochrome ash fca and lime as partial replacement of cement
Cement & Concrete Composites, 2016Co-Authors: Prasanna K Acharya, Sanjaya Kuma PatroAbstract:Abstract This paper presents the results of experimental investigations and microstructure study carried out to evaluate the possibility of utilization of Ferrochrome ash (FCA), a waste product from ferroalloys industries for partial replacement of cement in concrete preparation. FCA is used in four different substitution rates such as 10, 20, 30 and 40% along with 7% lime. Various strength and durability tests were conducted to understand the effects of FCA and lime on performance of concrete. Test results revealed that replacement of cement by FCA in various % with 7% lime enhanced the 28 days compressive strength 1.5–13.5%, flexural strength 4.5–9%, bond strength 15–29%, abrasion resistance 10–23% and reduced the sorptivity 25–43%. The concrete containing 40% FCA and 7% lime, replacing 47% of ordinary Portland cement (OPC) in total, exhibited strength of normal concrete or even more at all ages. XRD and petrography studies confirmed the results of mechanical and durability properties.
-
use of Ferrochrome ash fca and lime dust in concrete preparation
Journal of Cleaner Production, 2016Co-Authors: Prasanna K Acharya, Sanjaya Kuma PatroAbstract:Abstract Ferrochrome ash (FCA) is a discarded waste of the ferroalloys industry. The viability of FCA as a supplementary cementitious material for production of environmental friendly concrete is discussed in this paper. FCA is modified with lime dust to enhance the performance of concrete. To evaluate the functional behaviour of concrete made of FCA and lime, replacing equal mass of ordinary Portland cement (OPC), an experimental programme comprising a series of tests related to mechanical properties and durability were addressed at the age of 28, 91 and 180 days. FCA was substituted up to 40% in four different substitutions at an interval of 10%. Substitution of lime was considered as 7%, after studying its effect on blended cement based concrete. The impact of FCA and lime on properties of concrete was positive and encouraging at all ages. Results of 28 days, at highest replacement of 47% OPC (40% FCA and 7% lime) were close to those of normal concrete, for which maximum substitution of FCA is considered as 40%. Results were established by microscopic studies like petrography examinations. Relations between various properties were well compared having correlation coefficient nearer to 1. Utilization of FCA in concrete making will be helpful in reducing production of OPC, minimising green house emissions, lowering energy consumption, managing environmental burden and conserving natural resources.
-
utilization of Ferrochrome wastes such as Ferrochrome ash and Ferrochrome slag in concrete manufacturing
Waste Management & Research, 2016Co-Authors: Prasanna K Acharya, Sanjaya Kuma PatroAbstract:Solid waste management is one of the subjects essentially addressing the current interest today. Due to the scarcity of land filling area, utilization of wastes in the construction sector has become an attractive proposition for disposal. Ferrochrome ash (FA) is a dust obtained as a waste material from the gas cleaning plant of Ferro alloy industries. It possesses the chemical requirements of granulated slag material used for the manufacture of Portland cement. Ferrochrome slag (FS) is another residue that is obtained as a solid waste by the smelting process during the production of stainless steel in Ferroalloy industries. FS possesses the required engineering properties of coarse aggregates. The possibility of using FA with lime for partial replacement of ordinary Portland cement (OPC) and FS for total replacement of natural coarse aggregates is explored in this research. The combined effect of FA with lime and FS-addition on the properties of concrete, such as workability, compressive strength, flexural strength, splitting tensile strength and sorptivity, were studied. Results of investigation revealed improvement in strength and durability properties of concrete on inclusion of FA and FS. Concrete mix containing 40% FA with 7% lime (replacing 47% OPC) and100% of FS (replacing 100% natural coarse aggregate) achieved the properties of normal concrete or even better properties at all ages. The results were confirmed by microscopic study such as X-ray diffraction and petrography examination. Environmental compatibility of concrete containing FA and FS was verified by the toxicity characteristic leaching procedure test.
-
Sustainable use of industrial-waste as partial replacement of fine aggregate for preparation of concrete – A review
Elsevier, 2016Co-Authors: Manoj Kuma Dash, Sanjaya Kuma Patro, Ashoke Kuma RathAbstract:Utilisation of industrial waste materials in concrete compensates the lack of natural resources, solving the disposal problem of waste and to find alternative technique to safeguard the nature. There are a number of industrial wastes used as fully or partial replacement of coarse aggregate or fine aggregate. This review carries out a thorough assessment about industrial waste substances, which can be adequately utilised in concrete as fine aggregate substitution. This paper reviewed some of these industrial wastes like waste foundry sand, steel slag, copper slag, imperial smelting furnace slag (ISF slag), blast furnace slag, coal bottom ash, Ferrochrome slag, palm oil clinker etc. Out of these materials, maximum number of experiments have been conducted using waste foundry sand and copper slag as fine aggregate replacement, but still more examinations are required for other waste materials as replacement of sand in concrete. Different physical and mechanical properties of industrial waste as well as of industrial waste concrete, in which natural sand is substituted have been reviewed and comparisons are made between them. Deflection and leaching study review are carried out additionally and compared. It can be observed that the concrete where sand is replaced by copper slag, imperial smelting furnace slag, class F fly ash exhibits improved strength and durability properties, but it’s slump increases as the rate of replacement increases in the case of copper slag and the slump decreases in the case of class F fly ash. There is a less research work reported on Ferrochrome slag and palm oil clinker used as sand substitution, so it is felt that further detailed investigations are required
Nikolay Panichev - One of the best experts on this subject based on the ideXlab platform.
-
speciation of cr vi in environmental samples in the vicinity of the Ferrochrome smelter
Journal of Hazardous Materials, 2009Co-Authors: Hilda N Sedumedi, Khakhathi L Mandiwana, Prince Ngobeni, Nikolay PanichevAbstract:Abstract The impact of Ferrochrome smelter on the contamination of its environment with toxic hexavalent chromium, Cr(VI), was assessed by analyzing smelter dusts, soil, grass and tree barks. For the separation of Cr(VI) from Cr(III), solid samples were treated with 0.1 M Na2CO3 and filtered through hydrophilic PDVF 0.45 μm filter prior to the determination of Cr(VI) by electrothermal atomic absorption spectrometry (ET–AAS). Ferrochrome smelter dust was found to contain significant levels of Cr(VI), viz. 43.5 μg g−1 (cyclone dust), 2710 μg g−1 (fine dust), and 7800 μg g−1 (slimes dust) which exceeded the maximum acceptable risk concentration (20 μg g−1). The concentration of Cr(VI) in environmental samples of grass (3.4 ± 0.2), soil (7.7 ± 0.2), and tree bark (11.8 ± 1.2) collected in the vicinity of the chrome smelter were higher as compared with the same kind of samples collected from uncontaminated area. The results of the investigation show that Ferrochrome smelter is a source of environmental pollution with contamination factors of Cr(VI) ranging between 10 and 50.
-
electrothermal atomic absorption spectrometric determination of cr vi during Ferrochrome production
Journal of Hazardous Materials, 2007Co-Authors: Khakhathi L Mandiwana, Nikolay Panichev, Prince NgobeniAbstract:Abstract The level of the generation of hexavalent chromium during Ferrochrome production was checked. The concentration of Cr(VI) increases with each stage of Ferrochrome production, 7070 μg g −1 being the highest concentration encountered in the last stage of production (dust). This concentration exceeds the maximum acceptable total Cr concentration per 8 h by a factor of more than 1000. It was further observed that there is a higher contamination of soil by this pollutant closer to the plant than further away. The highest concentrations of Cr(VI) in soil and grass were found to be 12.7 and 4.2 μg g −1 , respectively. The results of the investigation indicate that the consumption of such grass by animals do not pose any health hazard, for concentrations of the toxic Cr species are very low. Therefore, the release of emissions, including dust, during Ferrochrome production, is a major contributor to occupational diseases and death to people working in Ferrochrome production plant or mine.
Muslum Murat Maras - One of the best experts on this subject based on the ideXlab platform.
-
fire resistance of geopolymer concrete produced from elazig Ferrochrome slag
Fire and Materials, 2016Co-Authors: Ibrahim Turkme, Mehmet Burhan Karakoc, Muslum Murat Maras, Fatih Kantarci, Ramazan DemirbogaAbstract:Summary This paper presents the effect of elevated temperatures up to 700 °C on compressive strength and water absorption of two alkali-activated aluminosilicate composites (one of them is river sand aggregate geopolymer concrete; the other one is crushed sand aggregate geopolymer concrete) and ordinary Portland cement based concretes. To obtain binding geopolymer material, Elazig Ferrochrome slag was ground as fine as cement, and then it was alkali activated with chemical (NaOH and Na2SiO3). Geopolymer concrete samples were produced by mixing this binding geopolymer material with aggregates. At each target temperature, concrete samples were exposed to fire for the duration of 1 h. Fire resistance and water absorption of geopolymer and ordinary Portland cement concrete samples were determined experimentally. Experimental results indicated that compressive strength of geopolymer concrete samples increased at 100 °C and 300 °C temperatures when compared with unexposed samples. In geopolymer concrete samples, the highest compressive strength was obtained from river aggregates ones at 300 °C with 37.06 MPa. Water absorption of geopolymer concrete samples increased at 700 °C temperature when compared with unexposed samples. However, a slight decrease in water absorption of concrete samples was observed up to 300 °C when compared with unexposed samples. SEM and X-ray diffraction tests were also carried out to investigate microstructure and mineralogical changes during thermal exposure. Copyright © 2016 John Wiley & Sons, Ltd.
-
sulfate resistance of Ferrochrome slag based geopolymer concrete
Ceramics International, 2016Co-Authors: Mehmet Burhan Karakoc, Muslum Murat Maras, Fatih Kantarci, Ramazan Demirboga, Ibrahim TurkmeAbstract:This paper presents the study of the performance of a new geopolymer binding material exposed to sulfate attack. Geopolymer binding material was obtained by alkaline activating FS with chemical materials (NaOH and Na2SiO3). Geopolymer concrete samples were produced by mixing this binding material with river sand and crushed sand aggregates. Test specimens were immersed in magnesium sulfate solutions (by weight 3%, 5% and 7%) for various periods of time and the durability of geopolymer concrete was investigated. The residual compressive strength (90 and 180 days), change in weight and length of samples, pH variation of solution and visual appearance of these samples were obtained experimentally. It was concluded that compressive strength of both geopolymer and Ordinary Portland Cement (OPC) based concrete samples decreases with increasing in MgSO4 content and exposure duration. After exposed to 7% MgSO4 solution for 180 days, the minimum decrease in compressive strength was seen 25% in geopolymer concrete samples with crushed sand aggregates.
-
mechanical properties and setting time of Ferrochrome slag based geopolymer paste and mortar
Construction and Building Materials, 2014Co-Authors: Mehmet Burhan Karakoc, Muslum Murat Maras, Ibrahim Turkmen, Fatih Kantarci, Ramazan Demirboga, Ugur M ToprakAbstract:Abstract Many researches have been done to investigate using raw materials in the production of geopolymer cements. This paper presents the effects of alkali dosage and silica modulus when using sodium metasilicate solution at different curing conditions on the geopolymerization of Ferrochrome slag (FS). As alkali activation for geopolymerization, NaOH and Na2SiO3 solution were used. Geopolymer cement was produced using FS as raw material with 3 different silica modulus (0.50, 0.60 and 0.70) and 4 different Na2O concentrations (4%, 7%, 10% and 12%). The setting time, hydration heat and compressive strength of geopolymer paste samples and compressive strength of geopolymer mortar samples were obtained. The setting time varied between 120 and 870 min, it showed variability depending on Na2O content. The highest 28 day compressive strength of the geopolymer paste samples was obtained from one with Na2O concentration of 7% and silica modulus of 0.70. Geopolymer mortars were prepared for the determination of compressive strength by adding FS:sand:alkali activator ratio 1:2:0.30, 0.35 and 0.40. The specimens were cured at 60 °C and 80 °C kept for 20 h and the other mortar samples were stored under laboratory conditions. Compressive strength of the material decreased, when w/b (water/binder) ratio increased. The highest 28 day strength of the geopolymer mortar was obtained at 0.30 w/b ratio and laboratory temperature curing conditions. The hydration heat of geopolymer paste samples was found to be less than normal Portland cements. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were investigated to study the microstructural properties of the geopolymers.