Identification of Chemical Bonds and Microstructure of Hydrated Tricalcium Silicate (C3S) by a Coupled Micro-Raman/BSE-EDS Evaluation

Zheyu Zhu; Zhongping Wang; Yue Zhou; Yuting Chen; Kai Wu

doi:10.3390/ma14185144

Identification of Chemical Bonds and Microstructure of Hydrated Tricalcium Silicate (C₃S) by a Coupled Micro-Raman/BSE-EDS Evaluation

Materials (Basel). 2021 Sep 8;14(18):5144. doi: 10.3390/ma14185144.

Authors

Zheyu Zhu^{1

2}, Zhongping Wang^{1

2}, Yue Zhou¹, Yuting Chen¹, Kai Wu^{1

2}

Affiliations

¹ Key Laboratory of Advanced Civil Engineering Materials, Ministry of Education, Tongji University, Shanghai 201804, China.
² China School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.

Abstract

Identifying the phase evolution and revealing the chemical bonds of hydrated cements accurately is crucial to regulate the performance of cementitious materials. In this paper, a coupled Raman/BSE-EDS analysis was proposed to determine the chemical bonds of tricalcium silicate hydrates and the interface transition zone (ITZ) between inner C-S-H and anhydrates. The results show that the Raman/BSE-EDS method can accurately identify the chemical bonds of inner C-S-H and inner ITZ regions, which confirms the mixed structure of inner C-S-H and nano calcium hydroxide (CH). The inner ITZ shows a lattice change region with a thickness of 700-1000 nm, which can be attributed to the pre-disassembly process of C₃S crystal. The successful application of coupled Raman/BSE-EDS provides new insight into the hydration process and multi-structure features of traditional cementitious materials.

Keywords: ITZ; calcium hydroxide; chemical bonding; coupled Raman/BSE-EDS analysis; inner C-S-H.

Abstract

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