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Caesium sorption by hydrated cement as a function of degradation state: experiments and modelling. To provide reliable K(d) data for Cs required for the performance assessment …
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Cement, one of the most important building materials, is a binding agent that sets and hardens to adhere to building units such as stones, bricks, tiles, etc. Cement generally refers to a very fine powdery substance chiefly made up of limestone (calcium), sand or clay (silicon), bauxite (aluminum), and iron ore, and may include shells, chalk ...
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ABSTRACT Recently, extremely high dose rates were detected in the three-layer concrete plugs of the units 2 and 3 at the Fukushima Daiichi Nuclear Power Plant. The high dose rates suggest that there are some trapping effects of radioactive materials on shield plugs when gas species and aerosols (e.g. CsOH and CsI) are released from the …
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4.1.2.1 Cement Pastes R d Values. Figure 4.1b shows the results from the literature review on R d values in pure cement systems, i.e. hardened cement paste without ballast or additional aggregates. All experimental data mentioned in Table A.3 (see Annex) are shown with the exception of two data points from Ochs et al. because they were …
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Cement Cesium Chromium Clays Cobalt Copper Diamond Diatomite Feldspar. Cover: Minerals play an integral part in all aspects of our lives. In this rural setting, minerals provide nutrients, such as nitrogen, phosphorus, potassium, and a host of micronutrients essential to maximize crop yields to ensure reliable food
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The Spruce. Cement (also called Portland cement) is a fine binding powder that is never used alone but is a component of both concrete and mortar, as well as stucco, tile grout, and thin-set adhesive.; Mortar is composed of cement, fine sands, and lime; it is used as a binding material when building with brick, block, and stone.; Concrete is a very …
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The leaching rate of cesium has been studied in cement. The solidification matrix was a standard Portland cement with increased sulphate resisting properties mixed with 300 kg/m 3 or 350 kg/m 3 powdered ion exchange resins, and with or without 5 weight-% zeolite added to the grout. The leaching rates from an ordinary cement matrix and a …
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cement, in general, adhesive substances of all kinds, but, in a narrower sense, the binding materials used in building and civil engineering construction. Cements of this kind are finely ground powders that, when mixed with water, set to a hard mass. Setting and hardening result from hydration, which is a chemical combination of the cement ...
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Uji slump adalah pengujian yang memerlukan peralatan uji tertentu, berikut peralatan yang biasa digunakan:. 1. Alat pertama untuk uji slump test beton adalah cetakan Kerucut Abrams yang terbuat dari logam. Diameter dasar sekitar 200mm, diameter atas sekitar 100 mm dan memiliki tinggi 300mm. 2. Tongkat penusuk harus berdiameter sekitar 26 mm …
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2.7.. Static leaching testStatic leaching tests were preformed, using ground water solution, to study the leaching of cesium and strontium ions from hardened blocks of cement and cement mixed with 4 wt.% synthetic zeolite A.The IAEA's standard test proposed by Hespe [15] was applied. All prepared samples (2.0 cm diameter and 2.0 cm …
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The adsorption activation energy determined from Arrhenius equation was found to be approximately 55.9 kJ mol (-1) suggesting that chemisorption was the …
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Abstract. As Kd from radwaste elements in concrete systems show a wide range of values, a modelling of cesium and lead immobilization in Calcium Silicate …
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Overview. Cesium is a metal element similar to lithium, sodium, and potassium. Non-radioactive cesium supplementation is sometimes called "high pH therapy." Those who promote "high pH therapy ...
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We reviewed washing of radioactive Cs-contaminated concrete and soil based on the fate of Cs in concrete and soil, including sorption materials for treatment of supernatant solution. In non-aged cement materials (the calcium silicate hydration (C–S–H) phase), it was possible to decontaminate Cs using ion exchange with monovalent …
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The efficiency of innovative matrices for immobilizing cesium is presented in this work. The matrix formulation included the use of fly ash belite cement (FABC-2-W) and gismondine-type Na-P1 zeolite, both of which are synthesized from fly ash of coal combustion. The efficiency for immobilizing cesium is evaluated from the leaching test …
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Many heterotrophic bacteria such as Vibrio, Acidobacteria, and Bacillus produce organic acids during their metabolism. Organic acids attack the concrete, causing decalcification of hydration ...
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Cesium-137 is a common radioactive byproduct found in nuclear spent fuel. Given its 30 year half life, its interactions with potential storage materials—such as cement paste—is of crucial importance. In this paper, simulations are used to establish the interaction of calcium silicate hydrates (C-S-H)—the main binding phase
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Experiments were carried out in a range of initial cesium concentrations from 0.0103 to 10.88 mg L (-1) and temperatures from 278 to 313 K using coupons of cement mortar immersed in the solutions ...
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The technical world of formates. Our Formate Technical Manual is by far the most comprehensive work on formate brines ever published. It contains information on cesium, potassium and sodium formate brines collated from 30 years of research and field experience. Split into three sections: chemical and physical properties, compatibilities and ...
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Binding mechanisms and leaching characteristics of cesium from different cement–bentonite immobilization matrices were investigated. The effect of Sr presence as a competitive contaminant in the matrices was studied by investigating the binding and leaching mechanisms in binary contaminant matrices that contains both Cs and Sr …
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Abstract. As Kd from radwaste elements in concrete systems show a wide range of values, a modelling of cesium and lead immobilization in Calcium Silicate Hydrate (CSH, xCaO.SiO {sub 2}.H {sub 2}O, with 0.7 (aged cements)
A study of the sorption and diffusion of iodide and cesium in slag cement paste and concrete in different aqueous environments is de-scribed in this report. 2. MASS TRANSFER IN A CONCRETE BARRIER 2.1. Some properties of cement and concrete Concrete may be considered as a porous solid mixture of essentially two phases: - a …
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"Without cesium being removed first, you would have to have a 6-foot-thick wall of concrete protection and the whole design concept would have to change, leading to higher costs as well."
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Concrete is a relatively cheap material and easy to be cast into variously shaped structures. Its good shielding properties against neutrons and gamma-rays, due to its intrinsic water content and relatively high-density, respectively, make it the most widely used material for radiation shielding also. Concrete is so chosen as biological barrier in …
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The leaching rate of 134Cs in cement has been studied. The solidification matrix by a standard Portland cement mixed with the spent ion-exchange resins was previously developed. The leaching rates from cement matrices were measured in function of pH, the immersion and curing times, the resin amounts, and 134Cs concentration. In all …
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Description: The sorption and desorption properties of radionuclides onto common building materials such as concrete are critical factors in the improvement of …
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Diffusion and sorption in cementitious materials are important factors influencing radionuclide migration in radioactive waste disposal. Four different experimental techniques have been used to study these processes for Cs+, Sr2+, and I− ions in Sulphate Resisting Portland Cement paste saturated with water. The results of different experimental …
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Nowadays, we typically use a 1:2:4 mix ratio when building a reinforced concrete single-story house. As a nickname, we can call this mix M15 grade, which comes from its corresponding 15 MPa compressive strength.If we want to build a 2-story house, we would need a stronger mix like the M20 grade mix, which follows a 1:1.5:3 mix ratio.. …
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The adsorption of cesium on cement mortar from aqueous solutions was studied in series of bench-scale tests. The effects of cesium concentration, temperature …
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It is known that cesium ions are strongly adsorbed into cement hydrate (CH) in concrete, a very porous substance. Cesium ions are presumed to diffuse with water in the porous …
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