The hydration of ordinary Portland cements OPC was investigated with X-ray powder diffraction XRPD technique, mainly using synchrotron radiation. In situ experiments were performed during the first hours of hydration to study the evolution of the crystalline phases in the system. The hydration was carried out with pure water and in the presence of additives such as superplasticizers and setting accelerating agents. As soon as water is added to the cement, ettringite crystallizes. Its evolution appears to be very complex, and lattice parameters change as a function of setting time, indicating a possible chemical evolution of ettringite with time and as a function of pH. CSH Ca-Si-hydrate forms after a few hours from the beginning of hydration. CSH can be indirectly quantified and its evolution studied.
The early hydration and the set of Portland cements: In situ X-ray powder diffraction studies
ARTIOLI, GILBERTO;
2007
Abstract
The hydration of ordinary Portland cements OPC was investigated with X-ray powder diffraction XRPD technique, mainly using synchrotron radiation. In situ experiments were performed during the first hours of hydration to study the evolution of the crystalline phases in the system. The hydration was carried out with pure water and in the presence of additives such as superplasticizers and setting accelerating agents. As soon as water is added to the cement, ettringite crystallizes. Its evolution appears to be very complex, and lattice parameters change as a function of setting time, indicating a possible chemical evolution of ettringite with time and as a function of pH. CSH Ca-Si-hydrate forms after a few hours from the beginning of hydration. CSH can be indirectly quantified and its evolution studied.Pubblicazioni consigliate
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