Geo-polymer concrete has gained attention of Civil engineers due to low carbon foot prints. In this study, M30 grade geo-polymer concrete is developed with fly ash, silica fume and quartz powder as source materials & Sodium Silicate and Sodium Hydroxide as an alkaline solution. Geo-polymer concrete mixes are prepared with alkaline solution to binder ratio as 0.35 by weight. The fly ash is replaced with silica fume & quartz powder in ratio of 5% and 10% to enhance mechanical properties, respectively. The concrete is cured at 60°c temperature in oven for 24 hours. The various parameters such as compressive strength, split tensile strength and workability are studied. Mechanical properties and optimum percentage of silica fume and quartz powder are investigated. In this experimental study, it is observed that presence of silica fume and quartz powder enhances the compressive strength up to 26% and split tensile strength up to 45%.
After the experiments were carried out and comparing of RPC with glass powder of 10%, 20% and 30%, conclusion can be made as follows. The maximum of average of compressive strength value that can be achieved in this study is 136 MPa for the RPC with glass powder of 20%. The RPC with glass powder of 20% indicates also the maximum of average of split tensile strength value of 17.8 MPa and the average of flexural strength value of 23.2 MPa. The use of glass powder of 20% of the mass of cement in this study is quite good to substitute the quartz powder in the RPC in order to improve its mechanical behavior.
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more complex. There is a need to replace a part of cement by some pozzolanic material to reduce the consumption of cement. In this study the effect of silica fume, quartz powder and steel fiber on M-40 grade concrete has been studied. Cement is replaced with silica fume at 10% by weight of cement. Simultaneously fine aggregate is replaced by quartz powder of about 20% by weight fraction and also Fibers were added in concrete to improve the mechanical properties. The test results of fibrous concrete for 7days, 28days were compared with conventional concrete and concrete without addition of steel fiber.
Compressive strength of concrete having more strength on 1.0% fibers+ 15% silica fume and quartz powder. Flexural strength of concrete having more strength on 1.0% fibers+ 15% silica fume and quartz powder. Split tensile strength of concrete having more strength on 1.0% fibers+ 15% silica fume and quartz powder. Acid attack test is having more strength on 1.0% fibers+ 15% silica fume and quartz powder. In this Acid Attack
Grain growth laws for samples of quartz powder and nova- culite were determined under wet conditions. The presence of water was necessary for grain growth to occur. Neverthe- less, the addition of water above 0.25 wt % did not result in increased rates of growth in the novaculite samples. Further- more, pores filled with water impeded grain growth, as can be inferred from comparisons between the powder and no- vaculite samples. The growth exponents, which significantly change growth rates, were determined as n = 2.5 ± 0.4 for the powder and n = 2.9 ± 0.4 for the novaculite. The two types of quartz sample also showed a dependence on water fugacity, and the fugacity exponents were r = 2.3 ± 0.3 for the pow- der and r = 1.9 ± 0.4 for the novaculite. We extrapolated our grain growth laws to natural conditions, and we discussed the effects on plastic deformation. Our grain growth laws in- dicate that after the deformation stage, dynamically recrys- tallized grains can grow, especially under lower-crustal con- ditions, when the system has enough time for grain growth. As a consequence, when grain size piezometers are applied to natural quartz, we should bear in mind that these are min- imum stresses because grain growth might have taken place. Even during the deformation stage, grain growth might com- pete with grain size reduction in dynamic recrystallization when the strain rate is < 10 −12 s −1 .
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compressive, split tensile and flexural strength in concrete. Slag, Pulverized Quartz powder and silica fume are used as cement replacement materials at 4%, 8%, 12%, 16% and 20% individually, finding the optimum replacement of cement based on cube compressive strength and an attempt is made for ternary blended concrete with16% of these three pozzolanic materials (slag + pulverized Quartz powder + silica fume) by three equal parts and tetra blended concrete with addition of 0.5-2.5% micro Al2O3 powder on 84% weight of cement. From the test results, it was found that tetra blended concrete mix with 16% pozzolanic materials and 1% of Al2O3 yielded higher compressive strength.
This project was overall interesting and from the results, Replacement of Fly Ash as admixture will be more workable than quartz powder satisfying all the tests such as Slump flow test, V – Funnel, U – Box method and L – Box method. For 20% replacement of cement by Quartz Powder, after 28 days of curing, self-compacting satisfying the target mean strength. Also, Split tensile strength concrete cylinder will have similar pattern of variation as compression strength. Similarly, for 20% replacement of cement by Fly ash, after 28 days of curing, self-compacting satisfying the target mean strength. Also, Split tensile strength concrete cylinder will have similar pattern of variation as compression strength. When it comes to Beams, the flexural behaviour of beam with Fly Ash performed well when compared to the specimen replaced with Quartz Powder. The ultimate load for specimen replaced with Fly Ash was increased when compared to specimen replaced with Quartz Powder.
Quartz, most ordinary of all minerals is self-possessed of silicon dioxide, or silica, SiO2. It is an vital component of igneous and metamorphic rocks. The size varies from specimens weighing a metric ton to minute particles that shine in rock surfaces. The crushed quartz powder used in the experiments is in a form of white powdered quartz flour, which replaces fine aggregate from the standard concrete. The particle size used ranges from 10 to 45μm.
Engineered Cementitious Composite (ECC) is a cement based material with ultra-high ductility and strength in tension. This material is a kind of high- performance fiber-reinforced cementitious composite materials (HPFRCCs) reinforced with short fibers and characterized by tight multiple cracking. These characteristics of ECC make it applicable to increase the capacity and the ductility of structural elements so that structural design is economic and sustainable. This paper presents an extended evaluation of Improved Engi- neered Cementitious Composites (IECC) for the use in the strengthening of masonry in filled reinforced concrete frames. IECC is a mixture of cement, fly ash, water, sand, quartz powder and poly-vinyl alcohol fibers with a better quality of tensile strain rather than common ECC. Two types of fine sand and quartz powder used in this study as filler to improve ECC behavior. Also, to show the effect of fly ash on IECC properties, five different mixtures were considered with various fly ash ratios. Different mixtures of IECC using fine aggregates produced in Iran were selected to find out how the aggregates and fly ash would affect IECC performance. The results show that the optimized mixture has the best characteristics including tensile strength and strain. Also, three-dimensional diagrams were used to compare the properties of different mixtures of IECC more effectively and to represent the influence of the range of fly ash ratios so that it can be opted based on design objectives such as ECC properties, costs and structural parameters and demands. These diagrams show the behavior of IECC which its fly ash content ratio in the binder is 50% to 67%.
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Arriving a optimal composition with locally available materials is important to achieve compressive strength more than 180 Mpa. Hence the effect of several parameters on compressive strength were investigated which comprise of percentages of quartz powder and duration of temperature and curing regimes. During the mixing it was observed that the mixes appeared to be very sensitive to any variation of the quartz powder, sand to be added to the mixes. Till a date there is no standard guidelines for mix design of RPC, literature was referred to the design mixes. A. DENSITY OF UHSC SPECIMENS
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The growth of concrete technology during the last decade has been mainly based on finding a suitable and eco-friendly substituent for cement. This project is synonymous to the same perception of finding an eco-friendly and feasible cementitious material. The reason trend is to incorporate industrial waste into concrete. Textile sludge is such a kind of industrial waste which is currently disposed by land filling that leads to ground water pollution and poor productivity of soil. In this study an attempt has been made to compare the mechanical strength of concrete of M30 grade by replacing cement by quartz powder and textile sludge respectively. Specimen were cast by replacing cement by quartz powder at 5,10 and 15 percentage by weight of cement and by textile sludge 5,10 and 15 percentage by weight of cement. An effort is also taken to investigate the combined effect of quartz powder and textile sludge on concrete by replacing quartz powder and textile sludge in equal proportion of 5, 10 and 15 percentage by weight of cement. Strength parameters such as compressive strength and split tensile strength were investigated. It was observed that the quartz powder of 10 % by weight of cement proved to be the optimum whereas on addition of textile sludge a decreasing trend was observed with 5% as the optimum.
Concrete is one of the necessary elements for structural work in the modern construction. In the decade, buildings around the world have become higher and so the structural strength demand for concrete is increased as they require high strength concrete. Ultra high strength concrete (UHSC) has been developed in the recent revolution of concrete. The major difference between ultra high strength concrete and conventional concrete is that no coarse aggregate is involved in ultra high strength concrete, but crushed quartz, quartz powder and fine river sands are used instead, with high dosage of silica fume. UHSC has exceptional mechanical properties and durability, ingredients of its includes cement, silica fume, quartz powder, quartz sand/river sand, steel fibres and it’s also called as Ductile concrete due to it’s high capacity to take load, deform and even support flexural tensile load after initial cracking. UHSC will be suitable for pre-stressed application and for structures acquiring light weight and their components such as roofs, stadiums, longer span bridges, space structure, high pressure pipes, blast resistance structure and containment of nuclear wastes
quality can be depicted on the association of its constituent materials and calcium-silicate-hydrates (CSH). Alteration of RPC quality ought to be conceivable by including quartz powder as one of the crucial constituent fragments. At present, the RPC with quartz powder to solid extent of 30% and steam reestablishing technique in an autoclave temperature of 250ºC, can accomplish a high compressive nature of 180 N/mm 2 and has a truly high flexibility .
in construction applications throughout the world. It is a mixture of cement, sand, coarse aggregate and water. The production of cement results in emission of many green house gases into atmosphere, which are responsible for global warming. In the present study, effect of pozzolanic (slag, silica fume, pulverized Quartz powder and) materials with addition of micro Fe2O3 is studied through compressive, split tensile and flexural strength in cement concrete. Slag, Quartz powder and silica fume are used as cement replacement materials at 4%, 8%, 12%, 16% and 20% individually, finding the optimum replacement of cement individually based on cube compressive strength and an attempt is made for quaternary blended concrete with16% of these three pozzolanic materials (slag + silica fume + pulverized Quartz powder) in three equal parts and penta blended concrete with addition of 0.5-2.5% of micro Fe2O3 powder with 16% in equal parts by weight of cement. The results were observed after 7&28 days of water curing for M20 grade of concrete. From the test results, it was found that concrete mix with 16% of quaternary blended cement and 2% of Fe2O3 yielded higher compressive strength. This experimental work proves that these pozzolanic materials can be used effectively as partial replacement materials for cement in the concrete and makes the concrete more economical and eco-friendly.
Abstract: Reactive powder concrete is a composite material used for strong and Durable structures. In this experimental study compressi ve strength of RPC with different dosages of nano-silica replacement is studied with combination of Quartz and Barite fine aggregates. compressive strength is carried out at the age of 28 days, the micro structural analysis SEM,EDS,FTIR shows formation of hydrated products like portlandite, Tobermorite, xonotlite and C-S-H gel.
solubility in both pure water and chlorine solution is relatively low (Kennedy, 1950; Rimstidt, 1997; Shmulovich et al., 2006). There is no experimental data on quartz solubility in complex fluids including chlorides, metals and sulphur. It is known though that dissolved silica ‘behaves in a rather intriguing way’ in complex systems (Akinfiev and Diamond, 2009). The presence of CO 2 in aqueous fluids lowers silica solubility, and the presence of salts can cause both a decrease (salting-out effect) and increase (salting-in effect) in silica solubility (Kennedy, 1950; Shmulovich et al., 2006). At 700°C the salting-out effect is maximal at high pressures (15 kbar) and weakens with a decrease in pressure (Akinfiev and Diamond, 2009), therefore, in porphyry environments it can be significant. Nevertheless, the abundance of quartz typically associated with porphyry-type deposits can only be precipitated as a result of the flow of ‘ unreasonably large volumes of fluid ’ (Wilkinson et al., 1996) or unreasonably high silica solubility. Large fluid volumes are not an issue for formation of the hydrothermal deposits, where large circulation cells can be implied, in which fluids can circulate for prolong periods and scavenge ore components from large volumes of rocks. It is believed though, that porphyry fluids are magma-derived (Burnham and Ohmoto, 1980; Cloos, 2001) and external fluids do not contribute significantly to formation of deposits of the type until the systems are cooled below 350°C (Gustafson, 1978). Therefore, if magmatic fluids do not contain sufficient amounts of metals then additional volumes of magma are required. External fluids in porphyry systems are only invoked to provide effective means of precipitation of ore minerals, e.g. as a result of fluids mixing (Wilkinson, 2001). Thus, in porphyry environments low solubility of metals, sulphur or silica in aqueous fluid can only indicate that the efficiency of metal extraction from magma is low and larger magma volumes must be involved.
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With the purpose of investigating the synergistic adsorption of polyethylene glycol (PEG) and N– dodecyl ethylenediamine (ND) on quartz surface, froth flotation accompanying with zeta potential measurements, FTIR studies, SEM/EDS analysis and molecular dynamics simulations were conducted in laboratory. Flotation results indicated that quartz flotation recovery could be improved significantly by the addition of PEG using ND as collector. The highest flotation recovery of quartz could be obtained when ND and PEG were mixed at a mass ratio of 1:1. Synthetic mixture of hematite and quartz could be separated at neutral slurry pH. Zeta potential measurements, FTIR analyses and SEM- EDS studies revealed the co–adsorption of PEG along with ND on quartz surface. The addition of PEG strengthened the electrostatic and hydrogen bond adsorption between quartz and collector. Furthermore, molecular dynamics simulations revealed the even stronger adsorption between ND/PEG mixture and quartz compared with ND or PEG adsorb individually.
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Tooth powder is a mildly powder that is used in combination with tooth brush to maintain oral hygiene. The manufacturing of tooth powder is a comparatively simple operation. The primary objective is the homogenous distribution of all the ingredients without contamination of foreign substances.
Macroscopic evaluation for the quartz body of the study area was done through geological field trips to detect the major sources of contaminations. Chemical composition for representative quartz samples was obtained by XRF analysis using the Pnalytical Axios Advanced XRF technique, was carried out at The Central Metallurgical Research and Development, Egypt. Petrographic investigations performed by Nicon transmitted polarized mi- croscope attached with computer program analysis to identify various impurities, their sizes, occurrence and their distribution.
Abstract. Hydrothermal quartz crystals, which occur in the Rusey Fault Zone (Cornwall, UK), show feathery tex- tures and network-like filamentous textures. Optical hot- cathodoluminescence (CL) analysis and laser ablation in- ductively coupled plasma mass spectrometry (LA-ICP-MS) investigations on quartz samples revealed that positions exhibiting feathery textures (violet luminescence) contain higher amounts of Al and Li than quartz positions without feathery textures (blue luminescence), while concentrations of Al and Li are significantly lower in feathery textures. Both Al and Li correlate negatively with Si. Raman spectroscopy investigations revealed the presence of a weak peak at 507– 509 cm −1 in quartz affected by feathery textures, which we attribute to the presence of ≤ 5 % moganite, a microcrys- talline silica polymorph, intergrown with chalcedony. The combined occurrence of feathery textures and network-like filamentous textures in quartz samples from the Rusey Fault Zone points to the presence of a metastable silica precursor (i.e., amorphous silica or silica gel) before or during the crys- tallization.
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