Polymer compounds have become a popular choice for the synthesis of novel products and are being used in cementitious mixtures principally for altering the properties in the fresh state and as repair materials. These polymers are used in various combinations. Their interaction with cement is worth studying because its hydration, followed by setting and …
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This study investigates the characteristics of alkali-activated slag cement using aluminium sulphate (ALS) as an activator. ... Sodium hydroxide and sodium silicate were also obtained from SAMCHUN Chemicals. The sodium hydroxide was in the form of pellets with a purity of 98.0%, and sodium silicate was in liquid form with a silicate modulus Ms ...
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Structural Concrete is a structural engineering journal publishing research on all aspects of concrete structures, including design, construction, demolition, and sustainability. ... Sodium hydroxide effect on the mechanical properties of flyash-slag based geopolymer concrete ... the 2.5 got the optimum point of the engineering strength among ...
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The Portland cement industry is an important sector that helps the construction industry make concrete and other cement-based products. Apart from water, concrete is the most widely consumed product in the world (Scrivener et al., 2018) [].The widespread and continuous use of ordinary Portland cement (OPC) contributes towards pollution due to the association of …
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The retardation effect of ZnO is attributed to the precipitation of zinc hydroxide onto the cement grains (Arliguie and Grandet, 1985). Zn(OH)2 has a low solubility (Ks = 1.8.10 –14) and is deposited as a colloidal gel; consequently, the precipitate has a low permeability. The retardation effect ends when the gelatinous zinc hydroxide ...
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Concrete is the widely used building material and cement is the main constituent in the manufacturing of concrete. With the intention of overcoming the environmental issues of cement, an effort ...
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Calcium, ammonium, barium and strontium hydroxides are normally harmless, but sodium hydroxide may cause damage. Salts are chemical compounds usually formed by reaction between acids and bases. Some of the salts best known for their damaging effects on …
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Decarbonizing calcium carbonate (CaCO3) is a crucial step for a wide range of major industrial processes and materials, including Portland cement (PC) production. Apart from the carbon footprint linked to fuel combustion, the process CO2 embodied within CaCO3 represents the main concern for the sustainability of production. Our recent works …
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based Geopolymer concrete by varying the concentration of Sodium hydroxide as 10, 12, 14M and the ratio of alkaline solution (SiO 3 2- / OH - ) as 1.0, 1.5, 2.0.
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Secondly, the ratio of potassium to sodium can vary in different cements with consequences for the total amount of K 2 O and Na 2 O present. Thirdly, the use of the term "Na 2 O-equivalent" implies that the effect of potassium and sodium is equivalent. However, there are numerous studies indicating that the influence of potassium and sodium ...
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The alkali content in DPSA also exceed the limit of alkali known as equivalent sodium oxide content of cement and expressed as (Na2O)=Na2O+0.658K2O allowed in cement [25], which may affect the ...
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In this paper, the mechanical performance of fly ash and Portland cement geopolymer activated with sodium hydroxide and sodium silicate solutions was studied. The Geopolymer Mortars (GM) were made from high calcium Fly Ash (FA) and ordinary Portland Cement (PC) with FA:PC weight ratios of 100:0, 95:5, 90:10, 85:15, and 80:20. The GMs were …
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Concentration of sodium hydroxide is the most important factor for geopolymer synthesis [10]. The solubility of aluminosilicate increases with increase in hydroxide concentration [11]. The use of …
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Reagent-grade sodium hydroxide (NaOH) in pellet form was used to increase the alkali content of the cement. In this study, Melflux® 4930F, a powder form of polycarboxylate …
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formation for sodium hydroxide effects on lignocellulose. The structural characteristics of lignocellulose and the altera-tions that occur due to the application of sodium hydroxide are detailed. This review also includes a brief description of the chemical reaction mechanism that ensues during the pretreatment.
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This article investigates the use of sodium hypochlorite (NaClO) and describes the effects of this destructive chemical upon the innovative use of polypropylene fibres within a marine concrete matrix. Polypropylene fibres were treated with NaClO (2.5%) and an artificial seawater, NaCl (3.5%), replicating a six-month maintenance regime at the site.
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The inorganic compounds which are useful as concrete dissolvers generally include inorganic acids such as hydrochloric, phosphoric, hypochlorous and carbonic acid. Salts of these acids and alkalies such as sodium-hydroxide, sodium bicarbonate and ammoniumsulfate are also eifective. What kills white mold on concrete?
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How exposure to sodium hydroxide could affect your health. The presence of sodium hydroxide in the environment does not always lead to exposure. In order for it to cause any adverse health effects ...
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342 Vol.25 No.2 HUANG Yun et al: Effect of Sodium Hydroxide on the… DOI 10.1007/s11595-010-3342-7 Effect of Sodium Hydroxide on the Properties of Phosphogypsum based Cement HUANG Yun, LIN Zongshou (Key Laboratory of Silicate Materials Science and Engineering Ministry of Education, Wuhan University of Technology, Wuhan 430070, China)
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Keywords: GGBS, sodium hydroxide, sodium silicate, geopolymer concrete, alkali activator solutions, coarse aggregat e. Manuscript Received 16 April 2024; Revised 5 August 2024; Published 12 October 2024 INTRODUCTION Cement is used excessively as a construction material throughout the world ranking only second after water.
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This work clarifies the impact of NaOH and Na 2 SO 4 on the kinetics and microstructural development of cement hydration to better understand their effect on the mechanical properties. Na 2 SO 4 and NaOH accelerate hydration and strength development during the first hours but lower strength values later on. For the same degree of hydration of …
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The sodium hydroxide molarity significantly impacts the flowability of geopolymer mortar. Research findings indicate that varying molarities of sodium hydroxide, such as 8M, 10M, 12M, 14M, and 16M, influence the workability and setting time of geopolymer mortar. Higher molar concentrations of sodium hydroxide, particularly at 16M, have been associated with enhanced …
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Keywords: Geopolymer, Slag, Alkaline Solution, Compressive strength, Sodium hydroxide, Sodium silicate. Introduction Cement is the major ingredient in the production of concrete. In the manufacturing of cement, equivalent amount of CO 2 is emitted to the atmosphere 1. The cement industry contributes 7% of the total CO 2
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Geopolymerization can transform a wide range of waste aluminosilicate materials into building and mining materials with excellent chemical and physical properties. The present experimental study investigates the effect of sodium silicate/sodium hydroxide ratios on the feasibility of geopolymer synthesis at 80 °C using fly ash. The sodium silicate/sodium …
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In contrast, for silica gel a higher rate of dissolution for potassium hydroxide than for sodium hydroxide has been observed experimentally [25]. Because little data exist on the combined effect of various ions [26], statements about the influence of K/Na-ratio on the rate of dissolution in alkaline conditions is difficult. The substantial ...
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Carbonation in concrete occurs when carbon dioxide (CO2) from the air reacts with calcium hydroxide in the concrete to form calcium carbonate. Facebook Instagram Linkedin Pinterest RSS Share Twitter Youtube
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According to Bernard Erlin, the principal chemicals in concrete that could conceivably attack plastics are calcium hydroxide, sodium hydroxide and potassium hydroxide. Erlin cites a table from Handbook of Chemistry and Physics stating that rigid PVC has excellent resistance to strong alkalies.
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Sodium hydroxide enhances the alkalinity of pore solution in cement paste, thus accelerating the dissolving rate of calcium aluminate phase and calcium silicate phase in the cement system [5]. During the cement hydration process sodium ion can be adsorbed into the structure of AFm and CSH gel [6], [7]. Aluminum hydroxide can react with calcium ...
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The sodium hydroxide was taken in the form of pellets. The sodium hydroxide (NaOH) solution was prepared by dissolving the pellets in distilled water. Therefore, it is preferred to prepare the Alkaline Activated Solution separately and mix them at the time of casting. Since a lot of heat is generated when sodium hydroxide pellets react with ...
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Concrete with sodium hydroxide and sulfate aggregates has gained more compressive strength than concrete with sodium hydroxide and clean aggregates. Also, in both clean and chloride environments, with increasing the age of concrete from 28 days to 60 and 90 days, better hydration is carried out and cement reacts more with water, which is one of ...
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The experimental results show that, NaOH as an alkali activator significantly reduces the cement setting time and improves the cement early strength. But the acceleration …
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In this regard, an experimental investigation has been made to study the variation in the Compressive Strength of slag based Geopolymer concrete by varying the concentration of …
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Summary 1. As the sodium hydroxide concentration in the mixing water was increased from 0 to 1 M: (a) the rates of production of cement gel and calcium hydroxide increased, and (b) the rate of consumption of gypsum increased and the period in which the solution remained saturated with respect to gypsum diminished.
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The ability to disolve fats and organic material makes sodium hydroxide an excellent paint stripper and de greaser its a lot less unpleasant to use than ammonia, but does require rinsing to remove the sodium hydroxide, wheras ammonia solution just evaporates, although any soaps it formed will remain behind unless rinsed.
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Certain chemicals like ammonium hydroxide, iodine, sodium hydroxide up to a 30% concentration, ammonium nitrate, acetylene, aluminum chloride (both anhydrous and in 20% concentration), and silver nitrate are specifically rated as having little or no effect on PVC.
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Increasing the alkalinity of cement pastes by adding sodium hydroxide is known to increase the initial rate of hydration, thereby increasing early strength. The effects on the …
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Geopolymer concrete is an innovative, sustainable, cementless, and eco‐friendly concrete that directly reduces the carbon footprints due to the total replacement of the cement from the concrete.
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