2009年4月1日 · Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) have been used to study the microstructural changes and phase development that take place during the hydration of cubic (pure) and orthorhombic (Na-doped) tricalcium aluminate (C3A) and gypsum in the absence and presence of lime.

2023年5月16日 · Being one of the important constituents of Portland and calcium sulfoaluminate cements, tricalcium aluminate (C 3 A) plays a crucial role in the hydration, workability, setting and durability of cement and thus of concrete. The properties of the cement pastes are directly linked to its hydration products and their microstructure development.

2009年4月1日 · Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) have been used to study the microstructural changes and phase development that take...

2012年7月1日 · The in-situ XRD results show that the reaction of C 3 A and ettringite to form monosulfoaluminate (and/or hydroxy-AFm) after gypsum depletion occurs rapidly. The microstructures observed by SEM show a rapid and significant densification of the matrix right after gypsum depletion with the precipitation of AFm platelets ( Fig. 12 ).

The XRD pattern of sample without gypsum ( fig. 6) indicates on the retardation of hydration in the first 24 hours, however, in the C 3 S + C 3 A + CaSO 4 x2H 2 O + MC70 system ( fig. 10),...

In this study the AFm phases have been generated through the hydration of tricalcium aluminate (C 3 A) in the presence of sulfate (anhydrite) and carbonate ions (limestone) in various...

2024年1月1日 · The XRD patterns of the samples after hydration stoppage were obtained by a Bruker D8 ADVANCE diffractometer with a 2θ range of 5°-70° with a step width of 0.02° and 0.15 s counting time per step. Rietveld calculations were performed for the quantitative analysis of C 3 A, gypsum and CA$H phases.

Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) have been used to study the microstructural changes and phase development that take place during the hydration of cubic (pure) and orthorhombic (Na-doped) tricalcium aluminate (C 3 A) and gypsum in the absence …

2024年4月4日 · Understanding the initial hydration progress of tricalcium aluminate (C 3 A) at molecular scale is thus crucial for tackling this challenge as it exhibits a proclivity for early-stage hydration...

2013年1月1日 · This paper describes quantification of crystalline and amorphous hydrates in C3A-Gypsum-Ca（OH）2 system by combining the XRD・Rietveld and ²⁷Al MAS-NMR analysis.