A quantitative study of the C3A hydration. (January 2019)

• Record Type: Journal Article
• Authors: Joseph, Shiju; Skibsted, Jørgen; Cizer, Özlem
• Is Part Of: Cement and concrete research. Volume 115(2019)
• Page Start: 145
• Page End: 159
• Publication Date: 2019-01
• Subjects: Tricalcium aluminate -- Hydration -- Kinetics -- Modelling; Cement -- Periodicals; Cement -- Research -- Periodicals; Concrete -- Periodicals; Concrete -- Research -- Periodicals; Ciment -- Périodiques; Béton -- Périodiques; Cement; Concrete; Periodicals; 620.135
• DOI: 10.1016/j.cemconres.2018.10.017
• Languages: English
• ISSNs: 0008-8846

Abstract

Abstract: The effect of fineness, gypsum content and water – cement (w/c) ratio on the hydration of C3 A systems have been quantitatively investigated using a combination of experimental techniques (isothermal calorimetry, TGA, XRD, 27 Al MAS NMR) and numerical modelling. It is proposed that the retardation of C3 A in the presence of calcium sulphates could be (or partially) due to the surface coverage of C3 A from ettringite precipitation. After the depletion of gypsum, the main calorimetric hydration peak is analyzed using a dissolution mechanism. The numerical model captures the main hydration peak, including peak broadening effects, which increase with the gypsum content and decrease with the fineness. It is found that the increase in w/c ratio (from 0.5 to 1.0) enhances the overall degree of hydration of C3 A by 7 days of hydration in systems with and without gypsum, which is attributed to the increase in free water with increasing w/c ratio.