Insight on the mechanical properties of hierarchical porous calcium-silicate-hydrate pastes according to the Ca/Si molar ratio using synchrotron X-ray scattering and nanoindentation test
その場放射光X線散乱とナノインデンテーションを用いたCa/Siモル比に応じた階層型多孔質ケイ酸カルシウム水和物ペーストの力学特性に関する知見
Im, S.*; Jee, H.*; Suh, H.*; 兼松 学*; 諸岡 聡 ; Choe, H.*; 西尾 悠平*; 町田 晃彦*; Kim, J.*; Lim, S.*; Bae, S.*
Im, S.*; Jee, H.*; Suh, H.*; Kanematsu, Manabu*; Morooka, Satoshi; Choe, H.*; Nishio, Yuhei*; Machida, Akihiko*; Kim, J.*; Lim, S.*; Bae, S.*
Nanocrystalline calcium-silicate-hydrate (C-S-H) is a typical heterogeneous material with a multiscale structure spanning a wide length scale from angstrom to micrometer, and whose structure is determined by the Ca/Si ratio. In this study, we directly applied compressive loads on synthetic C-S-H pastes with Ca/Si ratios of 0.6-1.2 and investigated their mechanical properties using the elastic modulus calculated at three length scale levels (i.e., angstrom to nanometer, micrometer, and millimeter) via in-situ synchrotron X-ray scattering, nanoindentation tests, and strain gauges, respectively. Further, Si nuclear magnetic resonance spectroscopy was conducted on the C-S-H pastes to elucidate the alterations in the silicate polymerization. The experimental results confirmed the deformation behavior of the C-S-H paste with different Ca/Si ratios under external loading, which was demonstrated to be transferred from the surface of the pastes to particles owing to the presence of multiscale pores.