Effect of calcium sulfate type and dosage on the properties …
High-belite sulfoaluminate cement (HBSC), with low carbon dioxide emissions, can be used to repair old concrete. Calcium sulfate plays a significant role in hydration of ye'elimite, …
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Overview of Concrete Deterioration Due to Sulphate Attack …
Structural environment plays a vital role in the service life of concrete structures, especially in the areas that have sever climate conditions such as the Arab gulf. ... (Rachel Detwiler, 2021) whereas calcium sulphate (CaSO4) is the least destructive since it is the least soluble. Even so, due to the production of ettringite, it will cause ...
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An Insight into the Chemistry of Cement—A Review
Even if cement is a well-consolidated material, the chemistry of cement (and the chemistry inside cement) remains very complex and still non-obvious. What is sure is that the hydration mechanism plays a pivotal role in the development of cements with specific final chemical compositions, mechanical properties, and porosities. This …
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The role of sulfate ions in tricalcium aluminate hydration: New
a b s t r a c t Presented within is a critical overview of the effect of sulfates on cement hydration, properties, and optimum sulfate content in Portland cement. Calcium sulfate is used in ...
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EFFECTS OF SULFATES ON THE HYDRATION OF …
The amount of calcium sulfate in the Portland cement influences the hydration, rheology, setting, phase assemblage, porosity distribution, and strength in cementitious materials.
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Impact of C3A Polymorphism, Lignosulfonate Admixture, …
The effect of C 3 A polymorphism, the calcium sulfate source, and the addition of limestone on the hydration kinetics and rheology of cement pastes and their interaction with a lignosulfonate-based admixture were analyzed. Two clinkers produced in industrial cement rotary kilns using the same raw materials and process were produced; …
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Effects of sulfates on the hydration of Portland cement – A …
Calcium sulfate is used in Portland cement to control the C 3 A reaction to induce the optimum hydration of C 3 S to occur. The amount of calcium sulfate in the Portland cement influences the hydration, rheology, setting, phase assemblage, …
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(PDF) Influence of calcium sulphate on hydration …
The amount of calcium sulfate in the Portland cement influences the hydration, rheology, setting, phase assemblage, porosity distribution, and strength in cementitious materials.
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Sulfate Attack on Concrete Designer's Perspective
Sulfate-Resistant Cement: The primary ingredient in concrete is cement, and using sulfate-resistant cement is the foundation of sulfate attack prevention. This type of cement contains a lower percentage of tricalcium aluminate (C 3 A), which is highly reactive with sulfates. It helps mitigate the chemical reactions that lead to expansion and ...
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Sensitivity Analysis of Damage in Cement Materials under Sulfate …
It is found that the damage progression rate is mostly dependent on relative rates of sulfate ingress and calcium leaching. The relations between the factors and the damage progression rate are observed to be significantly nonlinear. ... "The role of ettringite in external sulfate attack." Materials Science of Concrete: Sulfate Attack ...
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Injectable pregelatinized corn starch reinforced calcium sulfate cement
Composite bone cement (CSC/Starch) was formulated by calcium sulfate hemihydrate (CaSO4··0.5H2O, CSH) and pregelatinized corn starch in different mass ratios, along with deionized water acting as the setting solution at …
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Hydration mechanisms of supersulfated cement | Journal of …
The calcium sulfate ( ( {text {C}}overline {text {S}})) plays a crucial role in providing the SO 2- 3 ions, which react with the Ca 2+ and Al 3+ ions contained in …
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Effect of sulfate types on strength and swelling properties of …
Sulfate-bearing soils is widely distributed around the world, and this type of soil is prone to rock and soil disasters such as dissolution, corrosion of foundations, and …
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Role of polyferric sulphate in hydration regulation of …
Phosphogypsum-based excess-sulphate slag cement ... content and polymerisation, play an important role in the performance development and volume stability of PESSC binders. Through the addition of ... Fe 2 O 3)Si 0.84 ·4.32H 2 O), which will generate with the existence of calcium sulphate or carbonate (Dilnesa et al., 2014a, Dilnesa et al ...
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The role of sulfate ions in tricalcium aluminate hydration: New
As a major mineral of Portland cement, the hydration of tricalcium aluminate (C 3 A) has a significant impact on various properties of cement-based materials. However, there is little consensus on its mechanism, especially the interaction between C 3 A and gypsum which usually co-exist in cement systems. Recent researches have shown that …
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Sulfate Attack of Concrete
4.1 Calcium Sulfate Solutions (CaSO 4) The action of calcium sulfate is limited by its solubility in water, 15.2 mmol/l at 20°C (≈1.46 g SO 2− 4 /l). However, when these ions enter concrete, the pH is different and there is a change in the reactivity and solubility with respect to ground water.
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Hydration mechanisms of supersulfated cement
The calcium sulfate (CS) plays a crucial role in pro-viding the SO 3 2-ions, which react with the Ca2? and Al3? ions contained in GBFS to form ettringite (C 6AS 3H 32). With …
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The role of calcium carbonate in cement hydration
The diagram, Fig. 1, is constructed for lower temperatures, ∼ 25 °C, such that monosulfoaluminate tends to be persistent, although perhaps not actually stable [4].The impact of adding calcite on the paste mineralogy can be predicted as follows: select a horizontal line corresponding to the effective sulfur xide/alumina ratio, termed the …
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Effects of sulfates on the hydration of Portland cement – A …
Nowadays, the inclusion of calcium sulfate is an integral ingredient in Portland cement. Despite thousands of studies over several decades, many questions about the role of calcium sulfate on the cement phases (C 3 A and C 3 S) hydration, its mechanisms, and the so-called "optimum sulfate content" persists.
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Early-age hydration of ye'elimite (calcium sulfoaluminate …
Calcium sulfoaluminate-belite (CSAB) cement is considered a viable and environmentally friendly alternative to Portland cement. Ye'elimite or calcium sulfoaluminate which is the primary phase of CSAB cement undergoes rapid hydration, leading to the formation of ettringite or monosulfate as the major hydration product. The …
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Experimental investigation of metakaolin ingredients on …
1.Introduction. Over the past few years, there has been a growing effort to reduce CO 2 emissions in cement production and enhance the mechanical properties of cement-based materials. Pozzolanic clay has many applications in all fields and is used as an additive in cement (Zhang et al., 2022).One effective additive that has been widely used for this …
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Sulphate Attack on Concrete and Its Prevention
External Sulphate Attack (ESA) on Concrete. Sulphates (expressed as SO 3) present in the ground (or sea) water or soil attack hardened, relatively permeable concrete and react chemically with calcium hydroxide. The sources of sulphates can be one of the following: Sodium sulphate; Potassium sulphate; Magnesium sulphate; The …
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Alkali Silica Reaction and Sulfate Attack: Expansion of …
The sulfate ions, which come from soil, seawater, react with the cement hydrates (calcium hydroxide, C-S-H. AFm phases) to form ettringite, gypsum and thaumasite in presence of carbonates [1,2,3]. The use of supplementary cementitious materials to control the expansion is well established and a number of reviews have …
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Numerical investigation of the external sulfate attack …
External sulfate attack (ESA) is a dominant threat to the durability of concrete exposed permanently to sulfate environments, such as groundwater, sea water, salted soil, and saline lakes [1–3].The durability deterioration of concrete caused by ESA is a complicated chemo-mechanical process, which involves the sulfate diffusion in …
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Calcium silicate-based cements and functional impacts of …
The review purpose. The present review was conducted to evaluate the role of calcium silicate's constituents on its properties. Specifically, the potential effects of tricalcium silicate, dicalcium silicate, tricalcium aluminate, tertacalcium alumino ferrate, strontium salts, calcium sulfate, bismuth oxide, zirconium oxide, tantalum pentoxide, …
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Effect of calcium sulfate type and dosage on the properties …
Abstract High-belite sulfoaluminate cement (HBSC), with low carbon dioxide emissions, can be used to repair old concrete. Calcium sulfate plays a significant role in hydration of ye'elimite, but a comprehensive study of the effects of the four different types and dosages of calcium sulfate on the hydration of HBSC is lacking. This study …
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Effect of calcium sulfate source on the hydration of calcium
Design of self-dessicating binders using calcium sulfoaluminate cement: influence of the cement composition and sulfate source. Calcium sulfoaluminate (CSA) cements with a …
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Super sulfated cement: formulation and uses
The results show that the OPC content in the SSC composition also plays a central role to optim ize the . ... partially anhydrous calcium sulphate (90%) and Portland cement (10%), mixed …
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Application of Calcium Sulfate Whiskers to Cement-Based …
In recent years, significant attention has been paid to the use of calcium sulfate whiskers (CSWs) to enhance the performance of cement-based materials (CBM). This technology has attracted widespread interest from researchers because it enhances the performance and sustainability of CBM by modifying the crystal structure of calcium …
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Calcium
Calcium - Compounds, Reactions, Role: The most important calcium compound is calcium carbonate, CaCO3, the major constituent of limestone, marble, chalk, oyster shells, and corals. Calcium carbonate obtained from its natural sources is used as a filler in a variety of products, such as ceramics, glass, plastics, and paint, and as a …
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