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A first-principles insight into thermodynamic and mechanical properties of Xonotlite and Wollastonite phases of high temperature geothermal well cement

Abstract

This study investigates the thermodynamic and mechanical properties of two common calcium silicate phases, xonotlite (Ca6Si6O17(OH)2) and wollastonite (CaSiO3), in high temperature geothermal well cement using first-principles methods. Various properties, including thermal expansion coefficients, elastic constants, free energy, and entropy, were evaluated with the use of accurate anharmonic approximations at high temperatures. The study found that wollastonite has higher mechanical strength (97 GPa) compared to xonotlite (66 GPa) and lower thermal expansion, with decreasing values at higher temperatures. Volumetric thermal expansion coefficients were also calculated at different temperatures. These results demonstrate the potential of wollastonite as a suitable material for high-temperature cement dehydration processes.
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Category

Academic article

Language

English

Author(s)

Affiliation

  • SINTEF Industry / Materials and Nanotechnology
  • Norwegian University of Science and Technology
  • Ton Duc Thang University

Year

2023

Published in

Results in Materials

Volume

20

View this publication at Norwegian Research Information Repository