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The utilization of gypsum reinforced composites as building materials has garnered considerable attention owing to their exceptional amalgamation of mechanical strength, fire resistance, and versatile applications. This review initiates by introducing gypsum as a pivotal mineral in construction, subsequently exploring the concept of …
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Anhydrous gypsum was added as a chemical activator in varying proportions of 0, 2.5, 5, 7.5 and 10% by weight of the binder. The mortar was prepared using a binder:sand ratio was of 1:1.5 mass% and a water/binder ratio of 0.50. ... silica fume, fly ashes) and the natural resources (natural pozzolan, limestone and ...
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With natural anhydrite (type II anhydrous gypsum) from Hanshan Country of Anhui Province as major raw materials, the preparation and application of anhydrous plaster gypsum are investigated. The physical properties and mechanical properties, ventilation property and respiratory capability of anhydrous plaster gypsum with different …
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The swelling of clay-sulfate rocks is a well-known phenomenon often causing threats to the success of various geotechnical projects, including tunneling, road and bridge construction, and geothermal drilling. The origin of clay-sulfate swelling is usually explained by physical swelling due to clay expansion combined with chemical swelling associated …
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In this context, a complete characterization of the physical properties of Moroccan natural gypsum materials was carried out. Basic information on the mineralogical, microstructure, thermal, mechanical, …
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Another type of slag-containing cement is a supersulfated cement consisting of granulated slag mixed with 10 to 15 percent hard-burned gypsum or anhydrite (natural anhydrous calcium sulfate) and a few percent of portland cement. The strength properties of supersulfated cement are similar to those of portland cement, but it has an increased ...
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natural gypsum. In addition, anhydrite reacts more slowly, assisting concrete to achieve full strength over 30 days. Anhydrite was formerly mined on a large scale in England as …
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Anhydrous gypsum, also called dead-burnt gypsum, can be used as an exterior plaster that lasts over 100 years, and historically it was fairly commonly used in France and Belgium. In North America …
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At calcination temperatures above 350℃, type III anhydrous gypsum transforms into type II anhydrous gypsum or natural anhydrite characterized by dense and stable crystalline phase with...
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The industrial byproduct gypsum is a general term for byproducts discharged from industrial production with calcium sulfate as the main ingredient. Due to the high number of impurities and production volume, the industrial byproduct gypsum is underutilized, leading to serious environmental problems. At present, only …
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Anhydrous gypsum, also called dead-burnt gypsum, can be used as an exterior plaster that lasts over 100 years, and historically it was fairly commonly used in France and Belgium. In North America gypsum is hardly used by natural builders, however it could certainly play a greater role as an interior plaster, either on its own or mixed into ...
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Experimental process. To study the effects of microstructure and composition on the tensile strength of gypsum rocks, X-ray fluorescence spectrometry (XRF), elementary analysis and X-ray ...
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DOI: 10.1016/j.conbuildmat.2024.135503 Corpus ID: 268165860; Performance activation and strength evolution mechanism of carbide slag on anhydrous phosphogypsum backfill material @article{Zhou2024PerformanceAA, title={Performance activation and strength evolution mechanism of carbide slag on anhydrous …
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In the building materials, the industrial byproduct gypsum is mainly used in the production of cement retarders, gypsum slats, gypsum bricks, gypsum blocks, etc. In recent years, new gypsum products, such as self-leveling gypsum, α-type high-strength gypsum, ii-type anhydrous gypsum, and calcium sulfate whiskers, have also been …
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According to the amount of crystalline water, gypsum can also be categorised into dihydrate gypsum, hemihydrate gypsum, and anhydrous gypsum. Hemihydrate gypsum can be further classified as alpha-gypsum and beta-gypsum [26], which are considerably different in physical performance. The alpha-gypsum is well …
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The addition of 10% anhydrous gypsum showed a considerable improvement in the mechanical strength including flexure and compression. Because preparing MK is costly, of which it consumes high energy during kaolin calcination, it is better to replace it by any suitable waste or by-product material.
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Gypsum raw materials are available in two forms: as a natural gypsum stone (or anhydrite—anhydrous calcium sulfate) and as a byproduct of many industrial …
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This work has investigated the possibility of two common minerals (silica flour and talc powder) in modifying composite gypsum's physical and mechanical …
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In this study, precise control over the gypsum crystal and As species in Na 2 SO 4-H 2 SO 4 solutions under mild conditions facilitated the deep removal of As (with a leaching efficiency of 92.45 % and a final product As concentration of 80.32 ppm) and simultaneous preparation of high-strength α-bassanite (with a compressive strength of …
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Nearly 95% of the Brazilian production of natural gypsum comes from the state of Pernambuco, from the Araripe Gypsum Center. Of the 95%, that is to say, of the 1.3 million ton/year production, 61% is allotted to the making of blocks and plates, 35% for coverings, 3% for ceramic moulding, and 1% for other uses.
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The chemical compositions of clinker and natural dihydrate gypsum as well as the mineral phases of clinker calculated by Bogue's equations are shown in Table ... Hemihydrate gypsum reduces compressive strength at early ages and promotes strength after 28 days. Anhydrous gypsum decreases the compressive strength of cement paste.
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• High-strength gypsum cement specially formulated for use with glass fiber for fabricating glass-reinforced architectural details • Exceptionally quick setting; accepts most coatings and finishes • Low water requirements result in high-strength, high-density glass fiber-reinforced gypsum pieces • Ideal for producing lightweight, thin-cast,
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The deterioration of buildings and monuments by gypsum is the result of crystallization cycles of this salt. Although gypsum can dehydrate to a hemihydrate, the mineral bassanite, and to an anhydrate, the mineral anhydrite, this reaction occurs in nature on a geological time scale and therefore it is unlikely to occur when gypsum is found on …
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Activation treatment of natural and chemical anhydrous gypsum can make it adhesive and strong. So as to be suitable for the production of gypsum dry-mixed building materials. Acidic activators can accelerate the early hydration rate of anhydrous gypsum, shorten the setting time, and improve the early strength of gypsum hardened …
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Zhou et al. [22] conducted uniaxial and triaxial compression tests under natural and water saturated conditions for fresh gypsum rocks retained as pillars in Jinghua gypsum mine in Jingmen city in ...
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Table 2 Ion concentrations and maximum ionic strength for three Swiss tunnels in Gypsum Keuper. Full size table. ... Anhydrite appears in natural rocks either in the form of particles or of layers of different ... Bock E (1961) On the solubility of anhydrous calcium sulfate and of gypsum in concentrated solutions of sodium chloride at 25 °C ...
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According to the "Test method of cement mortar strength (ISO method)" (Chinese standard GB/T 17671–2021) and the mix proportion in Table 2, anhydrous phosphogypsum, carbide slag, and water-reducing agent were weighed and poured into a cement mortar mixer for pre-mixing for 30 s.Then, according to the mass ratio of dry …
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Natural Gypsum 1 Mineral Planning Factsheet Gypsum Continuous miner, Barrow-upon-Soar Mine, Leicestershire. This factsheet pro-vides an overview of the gypsum sup-ply in the UK. It is one of a series on economically important minerals that are extracted in Britain and it is primarily intended to inform the land-use planning process. January ...
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Gypsum (CaSO 4 2H 2 O) and anhydrite (CaSO 4) are the most common sulfate minerals.The predominant part of gypsum and anhydrite is used as raw materials for the production of gypsum binders (construction gypsum) and additives in various types of cements, to a lesser extent–for the production of hard-burnt, high-strength, molding …
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The characteristics of the gypsum pore structure are closely related to its macroscopic mechanical properties and permeability. ... (W 3 - W 1), where a is the purity, is the content of anhydrous calcium sulfate in anhydrite ore; 3.78 is determined by CaSO 4-hydrated / CaSO 4-total ... Relationship between porosity and strength of natural ...
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