Thermal stability of the phases developed at high-pressure hydrothermal curing of class G cement with different pozzolanic and latent hydraulic additives

Kuzielová, Eva; Slaný, Michal; Žemlička, Matúš; Másilko, Jiří; Šiler, Pavel; Palou, Martin

doi:10.1007/s10973-022-11254-2

Cited by 7 publications

(1 citation statement)

References 71 publications

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“…Cement strength retrogression, defined as the deterioration in strength and other properties at high curing temperatures (Craft et al, 1935;Swayze, 1954;Hesse et al, 2009), challenge the design of cementing slurries for high pressure and high temperature (HPHT) wells. Above 110 °C, calcium-silicate-hydrates (C-S-H) gel in cement slurry can be transformed into crystalline phases, resulting in a decrease in strength and an increase in permeability (Richardson, 2008;Bahafid et al, 2017;Jeong et al, 2018;Mabeyo, 2021;Kuzielová et al, 2022), which is believed to be the main cause of high temperature strength retrogression of cementitious materials. In the petroleum industry, various materials, such as silica flour, silica fume, rice husk ash, konilite, and basalt, have been added to the cement slurry to address the strength retrogression problem under high temperature (Ge et al, 2018;Paiva et al, 2019;Jiang et al, 2021;Santiago et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

Mechanism of long-term strength retrogression of silica-enriched Portland cement assessed by quantitative X-ray diffraction analysis

Qin

Pang

et al. 2022

Front. Mater.

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In order to clarify on the driving force of cement long-term strength retrogression, a comprehensive quantitative X-ray diffraction (XRD) analysis were conducted on silica-enriched (60%–80% by weight of cement) cement samples set and cured under the condition of 200°C and 50 MPa with a maximum duration of 180 days. The phase content evolution with time was determined by three different methods on the average of three specimens: the external standard method; the partial or no known crystal structure (PONKCS) method; and the hybrid method. Although the specific phase content estimated by different methods varied slightly, the overall trend of change of all phases were similar. The phase transformation in set cement at high temperature condition is dependent on the slurry composition. In silica-deficient system, tobermorite and amorphous C-S-H were transformed to xonotlite; while in silica-sufficient system, tobermorite and amorphous C-S-H were transformed to gyrolite. These phase transformations involve gradual structural changes of cement hydration products, which may be the driving force of long-term strength retrogression. However, such structural changes can only be detected by XRD once the transformation is complete.

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Section: Introductionmentioning

confidence: 99%

Mechanism of long-term strength retrogression of silica-enriched Portland cement assessed by quantitative X-ray diffraction analysis

Qin

Pang

et al. 2022

Front. Mater.

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Accelerated carbonation of oil-well cement blended with pozzolans and latent hydraulic materials

Kuzielová,

Slaný,

Žemlička

et al. 2023

J Therm Anal Calorim

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Accelerated carbonation of cement mixtures consisting of class G cement, silica fume, metakaolin, or blast furnace slag was studied by thermogravimetric, X-ray diffraction and Fourier transform infrared analyses for 1 year. Surface parts were fully carbonated during the first 7 days. Polymerization of amorphous hydrates due to their decalcification was observed together with the rising amount of calcium carbonates and reformation of gypsum from ettringite and monosulfate. Decalcification of clinker phases took place fast after the depletion of portlandite. Although portlandite was still present in unblended pastes, because of slower carbonation rate in the surface parts and higher C/S ratio of amorphous hydrates, the carbonation front moved inward during 3 months. Pozzolanic reactions in the samples with 30 mass% of additives depleted portlandite, however, higher amounts of C–(A)–S–H phases with lower C/S ratio, denser microstructure and faster carbonation of surface parts ensured their resistance against carbonation throughout the monitored period.

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Effect of cement paste and saline solution composition on chemical and physical binding of chlorides

Kuzielová,

Compeľová,

Peciar

et al. 2024

J Therm Anal Calorim

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Chloride ingress, along with chemical and physical binding in cement pastes, was studied in relation to the paste composition, saline solution, and hydration regime used. Unblended cement paste and pastes prepared with combinations of SF with MK and SF with BFS, replacing 30% of the cement mass, were exposed to NaCl and geothermal solutions for 7 days, either directly or following 7 days of water curing. The surface and middle parts of the samples were evaluated using TGA, XRD, FTIR, ion chromatography (Cl concentration), and ICP-OES (Na concentration). In addition, compressive strength (CS) measurements were performed. In MK-containing samples, Cl-AFm (hydrocalumite) formed mainly through an ion exchange mechanism, while in BFS-containing samples and the reference pastes, Cl-AFm phases primarily formed through the reaction of Cl− with C3A and Ca(OH)2 and increased physical adsorption of Cl− onto C-(A-)S-H were determined. Exposure to NaCl solution led to more chlorides being chemically incorporated into Cl-AFm, as well as higher levels of physically adsorbed and free chlorides in the pore solutions, compared to the geothermal solution. Pozzolanic reactions of additives, the acceleration of hydration induced by the solutions, especially by the geothermal one, and the densification of the matrix by the products of chloride reactions in blended samples resulted in CSs comparable to or higher than those reached after standard water curing. CSs of referential samples decreased following the decalcification of the initially formed C-(A-)S-H phases.

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Thermal stability of the phases developed at high-pressure hydrothermal curing of class G cement with different pozzolanic and latent hydraulic additives

Cited by 7 publications

References 71 publications

Mechanism of long-term strength retrogression of silica-enriched Portland cement assessed by quantitative X-ray diffraction analysis

Mechanism of long-term strength retrogression of silica-enriched Portland cement assessed by quantitative X-ray diffraction analysis

Accelerated carbonation of oil-well cement blended with pozzolans and latent hydraulic materials

Effect of cement paste and saline solution composition on chemical and physical binding of chlorides

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