Normal and anomalous self-healing mechanism of crystalline calcium silicate hydrates

Journal Article · Thu Apr 15 04:00:00 EDT 2021 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2021.106356· OSTI ID:23206353

Dupuis, Romain ^[1]; Moon, Juhyuk ^[2]; Jeong, Yeonung ^[3]; Taylor, Rae ^[4]; Kang, Sung-Hoon ^[2]; Manzano, Hegoi ^[5]; Ayuela, Andrés ^[6]; Dolado, Jorge S. ^[6]

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1. CNRS/MIT/AMU Joint Laboratory MultiScale Materials Science for Energy and Environment, UMI 2, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)
2. Department of Civil and Environmental Engineering, Institute of Construction and Environmental Engineering, Seoul National University (SNU), 1 Gwanak-ro Gwanak gu, Seoul 08826 (Korea, Republic of)
3. Construction Technology Research Center, Korea Conformity Laboratories (KCL), 199 Gasan digital 1-ro Geumcheon-gu, Seoul 08503 (Korea, Republic of)
4. Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)
5. Department of Physics, University of the Basque Country UPV/EHU, Barrio Sarriena s/n, 48940, Leioa, Bizkaia (Spain)
6. DIPC and CFM-MPC CSIC-UPV/EHU, p. Manuel de Lardizabal 4, 20018 Donostia-San Sebastián (Spain)

The origin of different stability of crystalline calcium silicate hydrates was investigated. The tobermorite crystal has been used as an analog of cement hydrate that is being mostly manufactured material on earth. Normal tobermorite is thermally unstable and transforms to amorphous at low pressure. Meanwhile, anomalous tobermorite with high Al content does not significantly transform under high pressure or high temperature. Conducted X-ray absorption spectroscopy explains the weak stability of normal tobermorite which was originally hypothesized by the role of zeolitic Ca ions in the cavities of silicate chains. Atomic simulations reproduced the experimentally observed trend of pressure behavior once the ideal structures were modified to account for the Al content as well as the chain defects. The simulations also suggested that the stability of tobermorite under stress could be rationalized as a self-healing mechanism in which the structural instabilities were accommodated by a global sliding of the CaO layer.

• OSTI ID: 23206353
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 142; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
CALCIUM IONS
CALCIUM OXIDES
CALCIUM SILICATES
CEMENTS
CRYSTALS
HEALING
HYDRATES
INSTABILITY
LAYERS
PRESSURE RANGE PA
SIMULATION
STABILITY
STRESSES
X-RAY SPECTROSCOPY
ZEOLITES