1. Opening letter of RILEM TC CS : Calcium sulfoaluminate-based cement and concrete – critical review and open questionsEric Bescher, Sabina Dolenec, Daniel Jansen, Thomas Matschei, Cameron Murray, Julio Paniagua, Elsa Qoku, Antonio Telesca, Robert Thomas, Frank Winnefeld, 2025, drugi znanstveni članki Povzetek: Calcium sulfoaluminate (CSA)-based cements represent a promising alternative to traditional Portland cement, offering benefits such as rapid strength development, low shrinkage, and reduced carbon footprint. Despite their commercial availability and proven performance, the adoption of CSA cements remains hindered by gaps in standardization and understanding. This RILEM Technical Committee (TC) CSA aims to review current knowledge, identify research needs, and address challenges related to clinkering, hydration mechanisms, durability, applications, nomenclature, standardization, and testing of CSA-based cements. The outcomes will further the understanding of manufacturing, technical performance, use, and specification of CSA-based cements, ultimately leading to broader acceptance in concrete construction.
Ključne besede: calcium sulfoaluminate cement, ye'elimite, belite, ettringite, low-CO2 cement
Objavljeno v DiRROS: 14.01.2026; Ogledov: 178; Prenosov: 107
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2. Phase development and hydration kinetics of belite-calcium sulfoaluminate cements at different curing temperaturesMaruša Mrak, Nina Daneu, Sabina Dolenec, 2020, izvirni znanstveni članek Povzetek: The influence of different curing temperatures on the hydration of belite-calcium sulfoaluminate cement was investigated at 20, 40 and 60 °C. The hydration kinetics and the hydrated phase assemblages were studied by isothermal calorimetry, X-ray powder diffraction, differential thermal analysis and thermogravimetric analysis, as well as field emission scanning electron microscopy. The compressive strength development of the cement pastes was also determined. Results showed that, at early ages, hydration was faster and early compressive strength was higher at elevated temperatures than at ambient temperature. On the other hand, at late ages in cement pastes cured at 60 °C, the amount of ettringite decreased, leading to lower compressive strength, indicating that the degree of hydration was lower at higher temperatures. Moreover, at elevated temperatures prismatic ettringite crystals became smaller due to faster hydration. Other hydration products present were aluminium hydroxide, which is formed together with ettringite from the hydration of calcium sulfoaluminate and gypsum, and C–S–H which precipitates as a main hydration product of belite. Belite hydrated in a lesser amount, especially at 60 °C, when the lowest amount of C–S–H was observed.
Ključne besede: hydration, cement, temperature, belite, calcium sulfoaluminate, open access, hidratacija, cement, temperatura, belit, kalcijev sulfoaluminat
Objavljeno v DiRROS: 04.08.2023; Ogledov: 1681; Prenosov: 1049
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3. The influence of calcium sulfate content on the hydration of belite-calcium sulfoaluminate cements with different clinker phase compositionsMaruša Mrak, Frank Winnefeld, Barbara Lothenbach, Sabina Dolenec, 2021, izvirni znanstveni članek Povzetek: The influence of different amounts of gypsum on the hydration of a belite-rich and a yeʼelimite-rich belite-calcium sulfoaluminate clinker (BCSA) was investigated. The hydration kinetics, phase assemblages and compressive strength development of cements prepared using yeʼelimite/ calcium sulfate molar ratios of 1, 1.5 and 2 were studied. Besides ettringite and monosulfate, aluminium hydroxide, strätlingite, C-S-H, iron-containing siliceous hydrogarnet and hydrotalcite were present as hydration products. Increasing the amount of gypsum increased the ratio of ettringite to monosulfate formed in the cement paste, lowered the amount of pore solution, delayed the dissolution of belite and ferrite, decreased the formation of strätlingite and, in the case of the yeʼelimite-rich BCSA, led to an increase in compressive strength. Increased amounts of belite in the clinker led to the formation of higher quantities of C-S-H, at the expense of straätlingite and a lower compressive strength, as belite has a lower degree of reaction than yeʼelimite and due to the formation of more C-S-H and stratlingite compared to the more space-filling ettringite. The thermodynamic model established for BCSA cement hydration agrees well with the experimental data. Compressive strength directly correlated with bound water from thermogravimetric analyses and inversely correlated with the porosity calculated from thermodynamic modelling.
Ključne besede: belite-calcium sulfoaluminate cement, gypsum, hydration, thermodynamic modelling
Objavljeno v DiRROS: 28.07.2023; Ogledov: 1556; Prenosov: 1191
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