Mechanisms of cement hydration

The current state of knowledge of cement hydration mechanisms is reviewed, including the origin of the period of slow reaction in alite and cement, the nature of the acceleration period, the role of calcium sulfate in modifying the reaction rate of tricalcium aluminate, the interactions of silicates and aluminates, and the kinetics of the deceleration period.

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The role of sulfate ions in tricalcium aluminate hydration: New

DOI: 10.1016/j.cemconres.2020.105973 Corpus ID: 212767437; The role of sulfate ions in tricalcium aluminate hydration: New insights @article{Liu2020TheRO, title={The role of sulfate ions in tricalcium aluminate hydration: New insights}, author={Xin Liu and Pan Feng and Chengjian Lyu and Shaoxiong Ye}, journal={Cement and Concrete Research}, year={2020}, …

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Hydration mechanisms of supersulfated cement: The role …

SSC have been used for decades and are usually composed of up to 90% blast furnace slag (BFS, SSC-BFS), 5-15% calcium sulfate (CS) and 5-15% of an alkaline activator; the latter is mainly Portland ...

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Insight into the role of early C3A hydration in structural …

Early cement hydration processes are predominantly dictated by silicate and aluminate reactions [8].The silicate reaction often involves the dissolution of alite (C 3 S) and the precipitation of portlandite (CH) and calcium silicate hydrate (C-S-H) [9, 10].The aluminate reaction encompasses the dissolution of tricalcium aluminate (C 3 A) and calcium sulfate …

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Exploring the Uses of Calcium Sulfate in Everyday Life

Calcium sulfate (CaSO₄) is a remarkable chemical compound that plays a significant role in various industries and daily life. This naturally occurring mineral exists in different forms depending on its hydration level, including anhydrous calcium sulfate, hemihydrate (CaSO₄·0.5H₂O), and dihydrate (CaSO₄·2H₂O).

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STUDIES OF THE ROLE OF CALCIUM SULPHATE IN THE …

SULPHATE IN PORTLAND CEMENT CLINKER MAY ORIGINATE FROM THE CLAY OR CALCIUM SULPHATE OF THE RAW MIX, FROM THE FUEL, OR FROM THE USE OF MINERALIZERS. ITS RETENTION IN THE CLINKER IS INFLUENCED BY THE KILN ATMOSPHERE. STUDIES ARE IN PROGRESS OF THE ROLE OF SULPHATE IN THE …

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Exploring the role of calcium sulfate in supersulfated cement: A study of rheological, mechanical, and microstructural …

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 …

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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 sulfate.

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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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Effect of calcium sulfate source on the hydration of calcium

Calcium sulfoaluminate clinker, industrially produced in China, and commercial micron natural gypsum (C S ‾ H 2) both marketed by BELITH S.P.R.L. (Belgium) were used as raw materials.Bassanite (C S ‾ H 0.5) and anhydrite (C S ‾) were prepared by heating the as-received gypsum at 90 °C for 48 h and at 700 °C for 1 h, respectively. Calcium sulfoaluminate …

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Influences of the type and amount of calcium sulphate …

The role of calcium sulphate as a setting -time regulator is widely known in the modern cement ... cement's performance under this particular poi nt of view, is still a fertile terrain for open discussions. ... gypsum to other calcium sulfate forms . The compositions are reported in the table 1, along with the

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Understanding the role of calcium formate towards …

Besides, the resistance to sulfate attack would be decreased by the large amount of inorganic salt accelerators [2]. Calcium formate (CF), considered as an environmental friendly cement accelerator, has been widely used in construction [23].

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Influence of Content and Source of Calcium Sulfate on …

Supersulfated cement (SSC) consists essentially of blast-furnace slag and calcium sulfate. It can be considered an alternative to Portland cement because its production minimizes the environmental impacts caused by the exploration of raw materials and CO 2 emissions. However, the long-term durability of SSC still needs to be studied.

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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; their crystallinity was changed …

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Understanding the role of calcium formate towards hydration and

Calcium formate (CF), considered as an environmental friendly cement accelerator, has been widely used in construction [23]. Moreover, as one kind of organic admixture, calcium formate will neither cause corrosion of steel as calcium chloride does [24], nor cause damage to human body as sodium nitrite does [25].

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Influence of Content and Source of Calcium Sulfate on …

Supersulfated cement (SSC) consists essentially of blast-furnace slag and calcium sulfate. It can be considered an alternative to Portland cement because its production …

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The Role Of Calcium Chloride In Concrete

Strong and durable, concrete is suited for virtually any exterior surface while being one of the most affordable building materials. It is a mixture of Portland cement, water, and aggregates such as sand, rock, or gravel. It does have limitations, but adding calcium chloride allows the mixture to set more quickly and increases its initial […]

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Influence of alkali sulfates in clinker on the hydration and …

Sulfate, a minor but important component, in Portland cement plays a significant role in cement concrete. The reaction of sulfate in cement with calcium aluminate affects the setting time, fluidity, compressive strength, volume stability and durability [1], [2].Adequate sulfate in cement would be beneficial to the setting time, development of compressive strength and …

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The role of calcium carbonate in cement hydration

The original cement contains a partially decomposed dihydrated calcium sulfate, which is regenerated after 1 h of hydration and is consumed in about 16 h of setting. ... 558 The role of calcium carbonate in cement hydration T. Matschei a,⁎, B. Lothenbach b, F.P. Glasser a a b Department of Chemistry, University of Aberdeen, Meston Building ...

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The role of Ca(OH)2 in sulfate salt weathering of ordinary concrete

Semantic Scholar extracted view of "The role of Ca(OH)2 in sulfate salt weathering of ordinary concrete" by Zanqun Liu et al. Skip to search form Skip to main ... the damage performances of sulfate salt weathering of Portland cement paste and calcium sulfoaluminate (CSA) cement paste were compared according to authors' previous studies. It was

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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 reactivity of ye'elimite can be …

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The influence of calcium sulfate content on the hydration of …

The influence of different amounts of gypsum on the hydration of a belite-rich and a ye'elimite-rich belite-calcium sulfoaluminate clinker (BCSA) was investigated. The hydration kinetics, phase assemblages and compressive strength development of cements prepared using ye'elimite/ calcium sulfate molar ratios of 1, 1.5 and 2 were studied. Besides ettringite and …

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Hydration mechanisms of supersulfated cement

Fig. 3 Compressive strength of SSC made with 10, 15 and 20% calcium sulfate (CS) and 0.2, 0.5, and 0.8% KOH: effect of alkaline activator for each CS content Hydration mechanisms of supersulfated cement: the role of alkali activator and calcium sulfate… 973 123

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Role of Gypsum in Cement and its Effects – …

Gypsum is a mineral and is hydrated calcium sulphate in chemical form. Gypsum plays a very important role in controlling the rate of hardening of the cement, so its is generally termed as retarding agent of cement. ... Composed of calcium sulfate and water, it is used for a variety of manufacturing, industrial, and agricultural uses. Its colour ...

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Effect of calcium sulfate type and dosage on properties of calcium

The amount and type of calcium sulfate play important roles in the formation of hydration products. When calcium sulfate is consumed totally and excess calcium aluminate exists, then it will react with ettringite and will result in the formation of monosulfoaluminate [6], [7], [8], which in turn, will increase the porosity of cement-based materials.

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Influence of calcium hydroxide and calcium sulfate on early …

A commercially available CSAB cement, laboratory-grade calcium sulfate dihydrate (gypsum) and calcium hydroxide were used in this study. The oxide and phase compositions of CSAB cement as determined from X-ray fluorescence (XRF) and quantitative X-ray diffraction (QXRD) are given in Table 1.The binder predominantly contained ye'elimite with an M-value of …

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Hydration mechanism of anhydrite and calcium …

Utilization of Portland cement to initiate the dissolution of blast furnace slag (BFS) in super-sulfated cement is limited by low slag substitution level and poor early strength. In this study, a new activator composed of anhydrite and calcium sulfoaluminate cement clinker was proposed to enhance the utilization of BFS in super-sulfated cement.

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The Role of Calcium Carbonate in Cement Hydration

The Role of Calcium Carbonate in Cement Hydration. April 2007; ... especially in high Al2O3 slag blended concrete. Sulfate optimization was performed on a total of 26 blended mixtures of 5 ...

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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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Study on the Effect of Three Types of Calcium Sulfate on the …

The best kind of calcium sulfate to use for making SCRM is anhydrite. A ternary cementitious system with an appropriate amount of calcium sulfate incorporated can effectively improve the …

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