Title: Study of Hydration Process of Cement Paste with Chemical Mapping

Author(s): Fengjuan Liu and Zhihui Sun

Publication: Materials Journal

Volume: 113

Issue: 5

Appears on pages(s): 609-619

Keywords: chemical mapping; hydration; microstructure; quantitative analysis; Raman spectroscopy

DOI: 10.14359/51689106

Date: 9/1/2016

Abstract:
In the present study, chemical mapping on the hydration process of cement pastes with water-cement ratios (w/c) of 0.35 to 0.60 was implemented by Raman spectroscopy (RS) from 12 hours after mixing until 28 days. Both the cement ingredients and hydration products were quantitatively studied. From the research, the content of calcium silicates (C3S and C2S) was observed to decrease rapidly during the first 3 days and then the decreasing rate slowed down. As one of the major hydration products, calcium hydroxide increased and tended to cluster in the pore vicinity with hydration progress. It was the only compound that could be detected as a pure phase in some measured regions. Ettringite was found to form on the surface of the unreacted cement particles, which was shown as a mixed zone of ettringite and calcium silicates in the maps. The RS chemical mapping results concurred with the scanning electron microscopy images collected from the same pastes.