Search results for: ground granule blast furnace slag

Authors: Bing Song, Kexi Han, Xuewei Lv

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Titania slag is a high quality raw material containing titanium in the subsequent process of titanium pigment. The effects of cooling approaches of granulating, water cooling, and air cooling on chemical, phases, and acidolysis of Panzhihua titania slag were investigated. Compared to the original slag which was prepared by the conventional processing route, the results show that the titania slag undergoes oxidation of Ti³⁺during different cooling ways. The Ti₂O₃ content is 17.50% in the original slag, but it is 16.55% and 16.84% in water cooled and air-cooled slag, respectively. Especially, the Ti₂O₃ content in granulated slag is decreased about 27.6%. The content of Fe₂O₃ in granulated slag is approximately 2.86% also obviously higher than water (<0.5%) or air-cooled slag (<0.5%). Rutile in cooled titania slag was formed because of the oxidation of Ti³⁺. The rutile phase without a noticeable change in water cooled and air-cooled slag after the titania slag was cooled, but increased significantly in the granulated slag. The rate of sulfuric acid acidolysis of cooled slag is less than the original slag. The rate of acidolysis is 90.61% and 92.46% to the water-cooled slag and air-cooled slag, respectively. However, the rate of acidolysis of the granulated slag is less than that of industry slag about 20%, only 74.72%.

Keywords: cooling approaches, titania slag, granulating, sulfuric acid acidolysis

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Authors: Junhai Liao, Yansong Shen, Aibing Yu

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A 3D numerical model is developed to simulate the complicated in-furnace combustion phenomena in the lower part of an ironmaking blast furnace (BF) while using pulverized coal injection (PCI) technology to reduce the consumption of relatively expensive coke. The computational domain covers blowpipe-tuyere-raceway-coke bed in the BF. The model is validated against experimental data in terms of gaseous compositions and coal burnout. Parameters, such as coal properties and some key operational variables, play an important role on the performance of coal combustion. Their diverse effects on different combustion characteristics are examined in the domain, in terms of gas compositions, temperature, and burnout. The heat generated by the combustion of upgraded Victorian brown coal is able to meet the heating requirement of a BF, hence making upgraded brown coal injected into BF possible. It is evidenced that the model is suitable to investigate the mechanism of the PCI operation in a BF. Prediction results provide scientific insights to optimize and control of the PCI operation. This model cuts the cost to investigate and understand the comprehensive combustion phenomena of upgraded Victorian brown coal in a full-scale BF.

Keywords: blast furnace, numerical study, pulverized coal injection, Victorian brown coal

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Authors: Dong Wook Lee, Seung Hyun Kim

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Trial blasting is conducted to identify the characteristics of the blasting of the applicable ground before production blasting and to investigate various problems posed by blasting. The methods and pattern of production blasting are determined based on an analysis of the results of trial blasting. The bedrock in Jeju Island, South Korea is formed through the volcanic activities unlike the inland areas, composed of porous basalt. Trial blasting showed that the blast vibration frequency of sedimentary and metamorphic rocks in the inland areas is in a high frequency band of about 80 Hz while the blast vibration frequency of Jeju Island is in a low frequency band of 10~25 Hz. The frequency band is analyzed to be low due to the large cycle of blasting pattern as blast vibration passes through the layered structured ground layer where the rock formation and clickers irregularly repeat. In addition, the blast vibration equation derived from trial blasting was R: 0.885, S.E: 0.216 when applying the square root scaled distance (SRSD) relatively suitable for long distance, estimated at the confidence level of 95%.

Keywords: attenuation index, basaltic ground, blast vibration constant, blast vibration equation, clinker layer

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Authors: Dong Wook Lee, Seung Hyun Kim

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Geological structure formed by volcanic activities shows polymorphic characteristics due to repeated cooling and hardening of lava. The Jeju region is showing polymorphic characteristics in which clinker layers are irregularly distributed along with vesicular basalt due to volcanic activities. Accordingly, resident damages and environmental disputes occur frequently in the Jeju region due to blasting. The purpose of this study is to develop a blast vibration equation considering the polymorphic characteristics of basaltic ground in Jeju. The blast vibration equation consists of a functional formula of the blasting vibration constant K that changes according to ground characteristics, and attenuation index n. The case study results in Jeju showed that if there are clinker layers, attenuation index n showed a distribution of -1.11~-1.87, whereas if there are no clinker layers, n was -2.79. Moreover, if there are no clinker layers, the frequency of blast vibration showed a high frequency band from 30Hz to 100Hz, while in rocks with clinker layers it showed a low frequency band from 10Hz to 20Hz.

Keywords: blast vibration equation, basaltic ground, clinker layer, blasting vibration constant, attenuation index

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Authors: K. K. Kaidarova, Ye. K. Aibuldinov, Zh. B. Iskakova, G. Zh. Alzhanova, S. Zh. Zayrova

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Currently, the existing road infrastructure of Kazakhstan needs the reconstruction of existing highways and the construction of new roads. The solution to this problem can be achieved by replacing traditional building materials with industrial waste, which in their chemical and mineralogical composition are close to natural raw materials and can partially or completely replace some natural binding materials in road construction. In this regard, the purpose of this study is to develop building materials based on the red sludge of the Pavlodar aluminum plant, blast furnace slag of the Karaganda Metallurgical Plant, lime production waste of the Pavlodar Aluminum Plant as a binder for natural loam. Changes in physical and mechanical properties were studied for uniaxial compression strength, linear expansion coefficient, water resistance, and frost resistance of the samples. Nine mixtures were formed with different percentages of these wastes 1-20:25:4; 2-20:25:6; 3-20:25:8; 4-30:30:4; 5-30:30:6; 6-30:30:8; 7-40:35:4; 8-40:35:6; 9-40:35:8 and the mixture identifier were labeled based on the waste content and composition number. The results of strength measurement during uniaxial compression of the samples showed an almost constant increase in strength and amounted to 0.67–3.56 MPa after three days and 3.33–7.38 MPa after 90 days. This increase in compressive strength is a consequence of the addition of lime and becomes more pronounced over time. The water resistance of the developed materials after 90 days was 7.12 MPa, and the frost resistance for the same period was 7.35 MPa. The maximum values of strength determination were shown by a sample of the composition 9-40:35:8. The study of the mineral composition showed that there was no contamination with heavy metals or dangerous substances. It was determined that road materials made of red sludge, blast furnace slag, lime production waste, and natural loam mixture could be used due to their strength indicators and environmental characteristics.

Keywords: production waste, uniaxial compression, water resistance of materials, frost resistance of samples

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Authors: Meysam Mousakhani, Reza Ziaie Moayed

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Considering the population growth and the needs of society, the improvement of problematic soils and the study of the application of different improvement methods have been considered. One of these methods is deep soil mixing, which has been developed in the past decade, especially in soft soils due to economic efficiency, simple implementation, and other benefits. The use of cement is criticized for its cost and the damaging environmental effects, so these factors lead us to use other additives along with cement in the deep soil mixing. Additives that are used today include fly ash, blast-furnace slag, glass powder, and potassium hydroxide. The present study provides a literature review on the application of different additives in deep soil mixing so that the best additives can be introduced from strength, economic, environmental and other perspectives. The results show that by replacing fly ash and slag with about 40 to 50% of cement, not only economic and environmental benefits but also a long-term strength comparable to cement would be achieved. The use of glass powder, especially in 3% mixing, results in desirable strength. In addition to the other benefits of these additives, potassium hydroxide can also be transported over longer distances, leading to wider soil improvement. Finally, this paper suggests further studies in terms of using other additives such as nanomaterials and zeolite, with different ratios, in different conditions and soils (silty sand, clayey sand, carbonate sand, sandy clay and etc.) in the deep mixing method.

Keywords: deep soil mix, soil stabilization, fly ash, ground improvement

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Authors: O. M. Omar, A. M. Heniegal, G. D. Abd Elhameed, H. A. Mohamadien

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Local steel slag is produced as a by-product during the oxidation of steel pellets in an electric arc furnace. Using local steel slag waste as a hundred substitute of crushed stone in construction materials would resolve the environmental problems caused by the large-scale depletion of the natural sources of dolomite. This paper reports the experimental study to investigate the influence of a hundred replacement of dolomite as a coarse aggregate with local steel slag, on the fresh and hardened geopolymer concrete properties. The investigation includes traditional testing of hardening concrete, for selected mixes of cement and geopolymer concrete. It was found that local steel slag as a coarse aggregate enhanced the slump test of the fresh state of cement and geopolymer concretes. Nevertheless the unit weight of concretes was affected. Meanwhile, the good performance was observed when fly ash used as geopolymer concrete based.

Keywords: geopolymer, molarity, steel slag, sodium hydroxide, sodium silicate

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Authors: Azadeh Askarinejad, Parham Hayati, Reza Parchami, Parisa Hayati

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One of the most important industries and building operations causing carbon dioxide emission is the cement and concrete related industries so that cement production (including direct fuel for mining and transporting raw material) consumes approximately 6 million Btus per metric-ton, and releases about 1 metric-ton of CO2. Reducing the consumption of cement with simultaneous utilizing waste materials as cement replacement is preferred for reasons of environmental protection. Blended cements consist of different supplementary cementitious materials (SCM), such as fly ash, silica fume, Ground Granulated Blast Furnace Slag (GGBFS), limestone, natural pozzolans, etc. these materials should be chemically activated to show effective cementitious properties. The present review article reports three different methods of nanofabrication that were used for activation of two types of SCMs.

Keywords: nanofabrication, cement replacement materials, activation, concrete

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Authors: Faraidoon Rahmanzai, Mizuki Takigawa, Yu Bomura, Shigeyuki Date

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To obtain the high quality and essential workability of mortar, different types of superplasticizers are used. The superplasticizers are the chemical admixture used in the mix to improve the fluidity of mortar. Many factors influenced the superplasticizer to disperse the cement particle in the mortar. Nature and amount of replaced cement by slag, mixing procedure, delayed addition time, and heat stimulation technique of superplasticizer cause the varied effect on the fluidity of the cementitious material. In this experiment, the superplasticizers were heated for 1 hour under 60 °C in a thermostatic chamber. Furthermore, the effect of delayed addition time of heat stimulated superplasticizers (SP) was also analyzed. This method was applied to two types of polycarboxylic acid based ether SP (precast type superplasticizer (SP2) and ready-mix type superplasticizer (SP1)) in combination with a partial replacement of normal Portland cement with blast furnace slag (BFS) with 30% w/c ratio. On the other hands, the fluidity, air content, fresh density, and compressive strength for 7 and 28 days were studied. The results indicate that the addition time and heat stimulation technique improved the flow and air content, decreased the density, and slightly decreased the compressive strength of mortar. Moreover, the slag improved the flow of mortar by increasing the amount of slag, and the effect of external temperature of SP on the flow of mortar was decreased. In comparison, the flow of mortar was improved on 5-minute delay for both kinds of SP, but SP1 has improved the flow in all conditions. Most importantly, the transition points in both types of SP appear to be the same, at about 5±1 min.  In addition, the optimum addition time of SP to mortar should be in this period.

Keywords: combined effect, delay addition, heat stimulation, flow of mortar

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Authors: Akshay Satishrao Kawtikwar

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The effect of blast masses on structures is an essential aspect that need to be considered. This type of assault could be very horrifying, who where we take it into consideration in the course of the design system. While designing a building, now not only the wind and seismic masses however also the consequences of the blast have to be take into consideration. Blast load is the burden implemented to a structure form a blast wave that comes straight away after an explosion. A blast in or close to a constructing can reason catastrophic harm to the interior and exterior of the building, inner structural framework, wall collapsing, and so on. The most important feature of blast resistant construction is the ability to absorb blast energy without causing catastrophic failure of the structure as a whole. Construction materials in blastprotective structures must have ductility as well as strength.

Keywords: blast resistant design, blast load, explosion, ETABS

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Authors: Nurcan Tugrul, Funda Demir, Hilal Ozkan, Nur Olgun, Emek Derun

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Geopolymers are aluminosilicate-containing materials. The raw materials of the geopolymerization can be natural material such as kaolinite, metakaolin (calcined kaolinite), clay, diatomite, rock powder or can also be industrial by-products such as fly ash, silica fume, blast furnace slag, rice-husk ash, mine tailing, red mud, waste slag, etc. Reactivity of raw materials in geopolymer production is very important for achieving high reaction grade. Fly ash used in geopolymer production has been calcined to obtain tetrahedral SiO₂ and Al₂O₃ structures. In this study, fly ash calcined at different temperatures (700, 800 and 900 °C), and Al₂O₃ addition (Al₂O₃ at min (0%) and max (100%)) were used to produce geopolymers. HCl dissolution method was applied to determine the geopolymerization percentage of samples and Fourier Transform Infrared (FTIR) Spectroscopy was used to find out the optimum calcination temperature for geopolymerization. According to obtained results, the highest geopolymerization percentage (0% alumina added geopolymer equal to 35.789%; 100% alumina added geopolymer equal to 40.546%) was obtained in samples using fly ash calcined at 800 °C.

Keywords: geopolymer, fly ash, Al₂O₃ addition, calcination

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Authors: Heba Al-Kelesh

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Day after day, high-grade iron ores are consumed. Because of the strong global demand for iron and steel, it has necessitated the utilization of various low-grade iron ores, which are not suitable for direct exploitation in the iron industry. The low-grade ores cannot be dressed using traditional mineral processing methods because of complicated mineral compositions. The present work is aimed to investigate the reducibility of some Egyptian iron ores and concentrates by conditions emulate different blast furnace areas. Representative specimens are collected from El-Gedida–Baharia oasis, Eastern South Aswan, and Eastern desert-wadi Kareem (EDC). Some mineralogical and morphological characterizations are executed. The reactivity arrangement of green samples is Baharia>Aswan>EDC. The presence of magnetite decreased reactivity of EDC. The reducibility of the Aswan sample is lower than Baharia due to the presence of agglomerated metallic grain surrounded by semi-melted phases. Specimens are annealed at 1000ᵒC for 3 hours. After firing, the reducibility of Aswan becomes the lowest due to the formation of fayalite and calcium phosphate phases. The relative attitude for green and fired samples reduced at different conditions are studied. For thermal and top areas, the reactivity of fired samples is greater than green ones, which were confirmed by morphological examinations.

Keywords: reducibility, low grade, iron industry, blast furnace

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Authors: Pravat Ranjan Pati, Alok Satapathy

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Linz-Donawitz (LD) slag a major solid waste generated in huge quantities during steel making. It comes from slag formers such as burned lime/dolomite and from oxidizing of silica, iron etc. while refining the iron into steel in the LD furnace. Although a number of ways for its utilization have been suggested, its potential as a filler material in polymeric matrices has not yet been explored. The present work reports the possible use of this waste in glass fiber reinforced epoxy composites as a filler material. Hybrid composites consisting of bi-directional e-glass-fiber reinforced epoxy filled with different LD slag content (0, 7.5, 15, 22.5 wt%) are prepared by simple hand lay-up technique. The composites are characterized in regard to their density, porosity, micro-hardness and strength properties. X-ray diffractography is carried out in order to ascertain the various phases present in LDS. This work shows that LD slag, in spite of being a waste, possesses fairly good filler characteristics as it modifies the strength properties and improves the composite micro-hardness of the polymeric resin.

Keywords: characterization, glass-epoxy composites, LD slag, waste utilization

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Authors: Sebastiano Candamano, Antonio Iorfida, Patrizia Frontera, Anastasia Macario, Fortunato Crea

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Alkali-activated materials are promising binders obtained by an alkaline attack on fly-ashes, metakaolin, blast slag among others. In order to guarantee the highest ecological and cost efficiency, a proper selection of precursors and alkaline activators has to be carried out. These choices deeply affect the microstructure, chemistry and performances of this class of materials. Even if, in the last years, several researches have been focused on mix designs and curing conditions, the lack of exhaustive activation models, standardized mix design and curing conditions and an insufficient investigation on shrinkage behavior, efflorescence, additives and durability prevent them from being perceived as an effective and reliable alternative to Portland. The aim of this study is to develop alkali-activated cements mortars containing high amounts of industrial by-products and waste, such as ground granulated blast furnace slag (GGBFS) and ashes obtained from the combustion process of forest biomass in thermal power plants. In particular, the experimental campaign was performed in two steps. In the first step, research was focused on elucidating how the workability, mechanical properties and shrinkage behavior of produced mortars are affected by the type and fraction of each precursor as well as by the composition of the activator solutions. In order to investigate the microstructures and reaction products, SEM and diffractometric analyses have been carried out. In the second step, their durability in harsh environments has been evaluated. Mortars obtained using only GGBFS as binder showed mechanical properties development and shrinkage behavior strictly dependent on SiO2/Na2O molar ratio of the activator solutions. Compressive strengths were in the range of 40-60 MPa after 28 days of curing at ambient temperature. Mortars obtained by partial replacement of GGBFS with metakaolin and forest biomass ash showed lower compressive strengths (≈35 MPa) and shrinkage values when higher amount of ashes were used. By varying the activator solutions and binder composition, compressive strength up to 70 MPa associated with shrinkage values of about 4200 microstrains were measured. Durability tests were conducted to assess the acid and thermal resistance of the different mortars. They all showed good resistance in a solution of 5%wt of H2SO4 also after 60 days of immersion, while they showed a decrease of mechanical properties in the range of 60-90% when exposed to thermal cycles up to 700°C.

Keywords: alkali activated cement, biomass ash, durability, shrinkage, slag

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Authors: Sukla Saha, Alok Sinha

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Acid mine drainage (AMD) refers to the production of acidified water from abandoned mines and active mines as well. The reason behind the generation of this kind of acidified water is the oxidation of pyrites present in the rocks in and around mining areas. Thiobacillus ferrooxidans, which is a sulfur oxidizing bacteria, helps in the oxidation process. AMD is extremely acidic in nature, (pH 2-3) with high concentration of several trace and heavy metals such as Fe, Al, Zn, Mn, Cu and Co and anions such as chloride and sulfate. AMD has several detrimental effect on aquatic organism and environment. It can directly or indirectly contaminate the ground water and surface water as well. The present study considered the treatment of AMD with metallurgical slag, which is a waste material. Slag helped to enhance the pH of AMD to 8.62 from 1.5 with 99% removal of trace metals such as Fe, Al, Mn, Cu and Co. Metallurgical slag was proven as efficient neutralizing material for the treatment of AMD.

Keywords: acid mine drainage, Heavy metals, metallurgical slag, Neutralization

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Authors: Karen Fuchs, Michael Prokein, Nils Mölders, Manfred Renner, Eckhard Weidner

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Due to the high CO₂ emissions, the energy consumption for the production of sand-lime bricks is of great concern. Especially the production of quicklime from limestone and the energy consumption for hydrothermal curing contribute to high CO₂ emissions. Hydrothermal curing is carried out under a saturated steam atmosphere at about 15 bar and 200°C for 12 hours. Therefore, we are investigating the opportunity to replace quicklime and sand in the production of building materials with different types of slag as calcium-rich waste from steel production. We are also investigating the possibility of substituting conventional hydrothermal curing with CO₂ curing. Six different slags (Linz-Donawitz (LD), ferrochrome (FeCr), ladle (LS), stainless steel (SS), ladle furnace (LF), electric arc furnace (EAF)) provided by "thyssenkrupp MillServices & Systems GmbH" were ground at "Loesche GmbH". Cylindrical blocks with a diameter of 100 mm were pressed at 12 MPa. The composition of the blocks varied between pure slag and mixtures of slag and sand. The effects of pressure, temperature, and time on the CO₂ curing process were studied in a 2-liter high-pressure autoclave. Pressures between 0.1 and 5 MPa, temperatures between 25 and 140°C, and curing times between 1 and 100 hours were considered. The quality of the CO₂-cured blocks was determined by measuring the compressive strength by "Ruhrbaustoffwerke GmbH & Co. KG." The degree of carbonation was determined by total inorganic carbon (TIC) and X-ray diffraction (XRD) measurements. The pH trends in the cross-section of the blocks were monitored using phenolphthalein as a liquid pH indicator. The parameter set that yielded the best performing material was tested on all slag types. In addition, the method was scaled to steel slag-based building blocks (240 mm x 115 mm x 60 mm) provided by "Ruhrbaustoffwerke GmbH & Co. KG" and CO₂-cured in a 20-liter high-pressure autoclave. The results show that CO₂ curing of building blocks consisting of pure wetted LD slag leads to severe cracking of the cylindrical specimens. The high CO₂ uptake leads to an expansion of the specimens. However, if LD slag is used only proportionally to replace quicklime completely and sand proportionally, dimensionally stable bricks with high compressive strength are produced. The tests to determine the optimum pressure and temperature show 2 MPa and 50°C as promising parameters for the CO₂ curing process. At these parameters and after 3 h, the compressive strength of LD slag blocks reaches the highest average value of almost 50 N/mm². This is more than double that of conventional sand-lime bricks. Longer CO₂ curing times do not result in higher compressive strengths. XRD and TIC measurements confirmed the formation of carbonates. All tested slag-based bricks show higher compressive strengths compared to conventional sand-lime bricks. However, the type of slag has a significant influence on the compressive strength values. The results of the tests in the 20-liter plant agreed well with the results of the 2-liter tests. With its comparatively moderate operating conditions, the CO₂ curing process has a high potential for saving CO₂ emissions.

Keywords: CO₂ curing, carbonation, CCU, steel slag

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Authors: Suresh Palla

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This research paper presents the results of the study on the estimation of fly ash, slag and cement contents in blended and composite cements by novel selective dissolution method. Types of cement samples investigated include OPC with fly ash as performance improver, OPC with slag as performance improver, PPC, PSC and Composite cement confirming to respective Indian Standards. Slag and OPC contents in PSC were estimated by selectively dissolving OPC in stage 1 and selectively dissolving slag in stage 2. In the case of composite cement sample, the percentage of cement, slag and fly ash were estimated systematically by selective dissolution of cement, slag and fly ash in three stages. In the first stage, cement dissolved and separated by leaving the residue of slag and fly ash, designated as R1. The second stage involves gravimetric estimation of fractions of OPC, residue and selective dissolution of fly ash and slag contents. Fly ash content, R2 was estimated through gravimetric analysis. Thereafter, the difference between the R1 and R2 is considered as slag content. The obtained results of cement, fly ash and slag using selective dissolution method showed 10% of standard deviation with the corresponding percentage of respective constituents. The results suggest that this novel selective dissolution method can be successfully used for estimation of OPC and SCMs contents in different types of cements.

Keywords: selective dissolution method , fly ash, ggbfs slag, edta

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Authors: Umashankar Morya, Somnath Basu

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Metalloids like arsenic are often present as contaminants in industrial effluents. Removal of the same is essential before the safe discharge of the wastewater into the environment. Otherwise, these pollutants tend to percolate into aquifers over a period of time and contaminate drinking water sources. Several adsorbents, including metal powders, carbon nanotubes and zeolites, are being used for this purpose, with varying degrees of success. However, most of these solutions are not only costly but also not always readily available. This restricts their use, especially among financially weaker communities. Slag generated globally from primary steelmaking operations exceeds 200 billion kg every year. Some of it is utilized for applications like road construction, filler in reinforced concrete, railway track ballast and recycled into iron ore agglomeration processes. However, these usually involve low-value addition, and a significant amount of the slag still ends up in a landfill. However, there is a strong possibility that the constituents in the steelmaking slag may immobilize metalloid contaminants present in wastewater through a combination of adsorption and precipitation of insoluble product(s). Preliminary experiments have already indicated that exposure to basic oxygen steelmaking slag does reduce pollutant concentration in wastewater. In addition, the slag is relatively inexpensive and available in large quantities and in several countries across the world. Investigations on the mechanism of interactions at the water-solid interfaces have been in progress for some time. However, at the same time, there are concerns about the possibility of leaching of metal ions from the slag particles in concentrations greater than what exists in the water bodies where the “treated” wastewater would eventually be discharged. The effect of such leached ions on the aquatic flora and fauna is yet uncertain. This has prompted the present investigation, which focuses on the leaching of metal ions from steelmaking slag particles in contact with wastewater, and the influence of these ions on the removal of contaminant species. Experiments were carried out to quantify the leaching behavior of different ionic species upon exposure of the slag particles to simulated wastewater, both with and without specific metalloid contaminants.

Keywords: slag, water, metalloid, heavy metal, wastewater

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Authors: Jeeja Menon, M. S. Ravikumar

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With the advent of green technology and the concept of zero energy buildings, there is an emerging trend in the utilization of indigenous materials like soil as a construction material. However, fine soils like clays and sand have undesirable properties and stabilization of these soils is essential before it is used to develop a building unit. Eco cement or Ground Granulated Blast Furnace Slag (GGBS), a waste byproduct formed during the manufacture of iron has cementitious properties and has the potential of replacing cement which is the most common stabilizer used for improving the geotechnical properties of soil. This paper highlights the salient observations obtained by the investigations into the effect of GGBS as a stabilizer for clayey sand. The index and engineering properties of the soil on the addition of different percentages (0%, 2%, 4%, 5% & 6% of the dry weight of the soil) of GGBS are tested to arrive at the optimum binder content. The criteria chosen for evaluation are the unconfined compressive strength values of different soil- binder composition. The test results indicate that there are significant strength improvements by the addition of GGBS in the soil, and the optimum GGBS content was determined as 5%. Moreover, utilizing waste binders for developing an ecofriendly, less energy induced building units as well as for stabilizing soil will also contribute to the solid waste management, which is the current environmental crisis of the world.

Keywords: eco cement, GGBS, index properties, stabilization, unconfined compressive strength

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Authors: Sonia Vanessa Campos Moreira

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The aim of this research is the production and mechanical properties of Alkali-Activated Inorganic Binders (AAIB) made from The Basic Oxygen Furnace Slag (BOF Slag) and Thin Film Transistor Liquid Crystal Display (TFT-LCD), glass powder (waste and industrial by-products). Many factors have an influence on the production of AAIB like the glass powder finesses, the alkaline equivalent content (AE %), water binder ratios (w/b ratios) and the differences curing process. The findings show different behavior in the AAIB related to the factors mentioned, the best results are given with a glass powder fineness of 4,500 cm²/g, w/b=0.30, a curing temperature of 70 ℃, curing duration of 4 days and an aging duration of 14 days results in the highest compressive strength of 18.51 MPa.

Keywords: alkaline activators, BOF slag, glass powder fineness, TFT-LCD, w/b ratios

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Authors: Jhuma Debnath, Hrishikesh Sharma

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The work done here in this paper is dedicated to studying the effect of high blast explosives over the seismically designed buildings. Buildings are seismically designed in SAP 2000 software to simulate seismic designs of buildings using response spectrum method. Later these buildings have been studied applying blast loads with the same amount of the blast explosives. This involved varying the standoff distances of the buildings from the blast explosion. The study found out that, for a seismically designed building, the minimum standoff distance is to be at least 120m from the place of explosion for an average blast explosive weight of 20kg TNT. This has shown that the building does not fail due to this huge explosive weight of TNT but resists immediate collapse of the building. The results also show that the adverse effect of the column failure due to blasting is reduced to 73.75% from 22.5% due to the increase of the standoff distance from the blast loads. The maximum affected locations due to the blast loads are also detected in this study.

Keywords: blast loads, seismically designed buildings, standoff distance, reinforced concrete buildings

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Authors: Michael I. Okereke, Ambrose I. Akpoyomare

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This paper presents a numerical study of the impact mechanic of metallic and sandwich structures incorporate with blast resistance enhancements. The study focuses on structures that have been exposed to improvised explosives devices (IEDs) attacks. The results show numerical conclusions on mechanisms to ensure blast resistance enhancement for the applications studied in this work. The work has identified optimal panel configuration both in geometry and configurations to ensure optimal blast resistance response to such IEDs discharges. Findings from this work will drive improvements in especially military and civilian vehicles in countries where blast attacks on vehicular occupants are quite rampant like Pakistan and Afghanistan.

Keywords: blast resistance, blast enhancement, explosives, material behavior

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Authors: B. Akturk, N. Yuzer, N. Kabay

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High temperature is one of the most detrimental effects that cause important changes in concrete’s mechanical, physical, and thermo-physical properties. As a result of these changes, especially high strength concrete (HSC), may exhibit damages such as cracks and spallings. To overcome this problem, incorporating polymer fibers such as polypropylene (PP) in concrete is a very well-known method. In this study, using RRH as a sustainable material instead of PP fiber in HSC to prevent spallings and improve physical and thermo-physical properties were investigated. Therefore, seven HSC mixtures with 0.25 water to binder ratio were prepared, incorporating silica fume and blast furnace slag. PP and RRH were used at 0.2-0.5% and 0.5-3% by weight of cement, respectively. All specimens were subjected to high temperatures (20 (control), 300, 600 and 900˚C) with a heating rate of 2.5˚C/min and after cooling, residual physical and thermo-physical properties were determined.

Keywords: high temperature, high strength concrete, polypropylene fiber, raw rice husk, thermo-physical properties

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Authors: V. K. Stalin, M. Kirithika, K. Shanmugam, K. Tharini

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Nanotechnology has been widely used in many applications such as medical, electronics, robotics and also in geotechnical engineering area through stabilization of bore holes, grouting etc. In this paper, an attempt is made for understanding the influence of nano copper slag (1%, 2% & 3%) on the index, compaction and UCC strength properties of natural soil (CH type) with and without lime stabilization for immediate and 7 days curing period. Results indicated that upto 1% of Nano copper slag, there is an increment in UC strength of virgin soil and lime stabilised soil. Beyond 1% nano copper slag, there is a steep reduction in UC strength and increase of plasticity both in lime stabilised soil and virgin soil. The effect of lime is found to show more influence on large surface area of nano copper slag in natural soil. For both immediate and curing effect, with 1% of Nano copper slag, the maximum unconfined compressive strength was 38% and 106% higher than that of the virgin soil strength.

Keywords: lime, nano copper slag, SEM, XRD, stabilisation

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Authors: V. K. Arora, V. G. Havanagi, A. K. Sinha

Abstract:

Copper slag and Jarofix are waste materials, generated during the manufacture of copper and zinc respectively, which have potential for utility in embankment and road construction. Accordingly, a research project was carried out to study the characteristics of copper slag and Jarofix to utilize in the construction of road. In this study, copper slag and Jarofix were collected from Tuticorin, State of Tamil Nadu and Hindustan Zinc Ltd., Chittorgarh, Rajasthan state, India respectively. These materials were investigated for their physical, chemical, and geotechnical characteristics. The materials were collected from the disposal area and laboratory investigations were carried out to study its feasibility for use in the construction of embankment and sub grade layers of road pavement. This paper presents the results of physical, chemical and geotechnical characteristics of copper slag and Jarofix. It was concluded that copper slag and Jarofix may be utilized in the construction of road.

Keywords: copper slag, Jarofix waste, material, road construction

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Authors: M. Murmu, Govardhan, J. Satya Eswari

Abstract:

Concrete is the most common and widely used building material. Concrete is basically made of aggregates, both fine and coarse, glued by a cement paste which is made of cement and water. Each one of these constituents of concrete has a negative environmental impact and gives rise to different sustainability issues. The current concrete construction practice is unsustainable because, not only it consumes enormous quantities of stones, sand, and drinking water, but also one billion tons a year of cement, which is not an environment friendly material. Preventing the reduction of natural resources and enhancing the usage of waste materials has become a challenge to the scientist and engineers. A number of studies have been conducted concerning the protection of natural resources, prevention of environmental pollution and contribution to the economy by using this waste material. This paper outlines the influence of Ground Granulated Blast furnace Slag (GGBS) as partial replacement of fine aggregate on mechanical properties of concrete. The strength of concrete is determined having OPC binder, replaced the fine aggregate with15%, 30%, 45% respectively. For this purpose, characteristics concrete mix of M25 with partial replacement of cement with GGBS is used and the strength of concrete cubes and cylinder have determined. The strength of concrete specimens has been compared with the reference specimen. Also X-ray diffraction (XRD) and scanning electron microscope (SEM) tests have been performed to examine the hydration products and the microstructure of the tested specimens. A correlation has been established between the developmental strength concrete with and without GGBS through analysis of hydration products and the microstructure.

Keywords: GGBS, sand, concrete, workability

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Authors: Meftah M. Elsaraiti, Samir Milad Elsariti

Abstract:

Steel slag is a by-product of the steel production and utilizing it potentially as new or substitute materials in road construction is advantageous regarding cost reduction and flattening improvement or properties pavement. Ease of use, low cost, and resource availability are some of few advantages of reuse and recycling of steel slag. This study assesses the use of Steel Slag Aggregates (SSA) as an alternative to natural road building aggregates. This paper discusses the basic characteristics of steel slag based on extensive laboratory tests, and to determine the possibilities of using steel slag in road construction. Samples were taken from the furnaces directly at different times and dates. Moreover, random samples were also taken from the slag field from various areas at different far distances from each other. A necessary analysis was performed through the use of (XRF). Three different percentages of SSA (0, 50 and 100%) were added as an alternative to natural aggregate in hot mix asphalt (HMA) production. The proposed design of the mix was made according to the Marshall mix design. The results of the experiments revealed that the percentages of iron oxide ranged from (9 to 26%) and that the addition of SSA has a significant improvement on HMA properties. It was observed that the Marshall stability obtained in the mix of 100% slag ranged from 600 to 800 N as a minimum, and the flow of Marshall obtained from 2.4 to 3.23 mm and the specification requires from 2 to 4 mm. The results may be showed possibilities to use steel slag as new or substitute materials in road construction in Libya.

Keywords: by-product material, properties, road construction, steel slag

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Authors: Zhang Haiyan, Su Zujun, Zhao Fengqi

Abstract:

Lepidolite after extraction of Lithium by sulfate produced many jarosite slag which contains a lot of Rb and Cs.The separation and recovery of Rubidium(Rb) and Cesium(Cs) can make full of use of Lithium mica. XRF analysis showed that the slag mainly including K Rb Cs Al and etc. Fractional solvent extraction tests were carried out; the results show that using20% t-BAMBP plus 80% sulfonated kerosene, the separation of Rb and Cs can be achieved by adjusting the alkalinity. Extraction is the order of Cs Rb, ratio of Cs to Rb and ratio of Rb to K can reach above 1500 and 2500 respectively.

Keywords: cesium, jarosite slag, rubidium, solvent extraction, t-BAMBP

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Authors: Mahdi Babaee, Arnaud Castel

Abstract:

One of the main hurdles for commercial adaptation of geopolymer concrete (GPC) as a low-embodied-carbon alternative for Portland cement concrete (PCC) is the durability aspects and its long-term performance in aggressive/corrosive environments. GPC is comparatively a new engineering material and in the absence of a track record of successful durability performance, proper experimental studies to investigate different durability-related characteristics of GPC seem inevitable. In this context, this paper aims to study the bulk electrical resistivity of geopolymer mortars fabricated of blends of low-calcium fly ash (FA) and ground granulated blast-furnace slag (GGBS). Bulk electrical resistivity is recognized as one of the most important parameters influencing the rate of corrosion of reinforcing bars during the propagation phase of corrosion. To investigate the effect of alkali concentration on the resistivity of the samples, 100x200 mm mortar cylinders were cast at different alkali concentration levels, whereas the modulus ratio (the molar ratio of SiO2/Na2O) was fixed for the mixes, and the bulk electrical resistivity was then measured. Also, the effect of the binder composition was assessed with respect to the ratio of FA to GGBS used. Results show a superior performance of samples with higher GGBS content. Lower concentration of the solution has increased the resistivity by reducing the amount of mobile alkali ions in the pore solution. Moreover, GGBS-based samples showed a much sharper increase in the electrical resistivity with decreasing the moisture content.

Keywords: bulk resistivity, corrosion, durability, geopolymer concrete

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Authors: Gyo Woo Lee, Man Young Kim

Abstract:

A mathematical heat transfer model for the prediction of transient heating of the slab in a direct-fired walking beam type reheating furnace has been developed by considering the nongray thermal radiation with given furnace environments. The furnace is modeled as radiating nongray medium with carbon dioxide and water with five-zoned gas temperature and the furnace wall is considered as a constant temperature lower than furnace gas one. The slabs are moving with constant velocity depending on the residence time through the non-firing, charging, preheating, heating, and final soaking zones. Radiative heat flux obtained by considering the radiative heat exchange inside the furnace as well as convective one from the surrounding hot gases are introduced as boundary condition of the transient heat conduction within the slab. After validating thermal radiation model adopted in this work, thermal fields in both model and real reheating furnace are investigated in terms of radiative heat flux in the furnace and temperature inside the slab. The results show that the slab in the furnace can be more heated with higher slab emissivity and residence time.

Keywords: reheating furnace, steel slab, radiative heat transfer, WSGGM, emissivity, residence time

Procedia PDF Downloads 258