[S-CG58] Innovation through the Integration of Solid Earth Science and Materials Science

[SCG58-P02] Structural and electronic properties of ettringite under high temperatures

*Satoshi Ohmura¹, Tomohiro Sasaoka¹, Ikumi Kanemasu¹ (1.Hiroshima Institute of Technology)

Ettringite (Ca₆[Al(OH)₆]₂(SO₄)₃·26H₂O) is a hydration product of Portland cement that plays a crucial role in the early strength development of cementitious materials. This mineral is rare in nature but is formed during the hydration process of cement through the reaction between calcium aluminate and calcium sulfate. Recently, delayed ettringite formation (DEF) has gained attention as a degradation mechanism in concrete structures. DEF is a phenomenon that occurs in mass concrete that has experienced an initial high-temperature history, as the temperature drops after the structure has hardened. To investigate the temperature dependence of the local structures of ettringite from an atomic perspective, we performed ab initio molecular dynamics simulations at temperatures up to 900K.