%0 Journal Article %T Assessment of the elastic properties of amorphous calcium silicates hydrates (I) and (II) structures by molecular dynamics simulation %+ Xi'an Shiyou University %+ Laboratoire de Génie Civil et Génie Mécanique (LGCGM) %A Fu, Jia %A Bernard, Fabrice %A Kamali-Bernard, Siham %Z China Scholarship Council (CSC) %< avec comité de lecture %@ 0892-7022 %J Molecular Simulation %I Taylor & Francis %V 44 %N 4 %P 285-299 %8 2018 %D 2018 %R 10.1080/08927022.2017.1373191 %K Nanoscale %K amorphous C-S-H structure %K molecular dynamics %K tensional deformation %K Young's modulus %Z Engineering Sciences [physics]/Civil Engineering %Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanical engineering [physics.class-ph]Journal articles %X Based on Hamid model of 11 angstrom tobermorite, amorphous calcium silicates hydrates (or C-S-H) structures (Ca4Si6O14(OH)(4)center dot 2H(2)O as the C-S-H(I) and (CaO)(1.67)(SiO2)(H2O)(1.75) as the C-S-H(II)) with the Ca/Si ratio of 0.67 and 1.7 are concerned. Then, as the representative globule' C-S-H, two amorphous C-S-H structures with the size of 5.352x4.434x4.556nm(3) during the stretch process are simulated at a certain strain rate of 10(-3)ps(-1) by LAMMPS program for molecular dynamics simulation, using ClayFF force field. The tensile stress-strain curves are obtained and analysed. Besides, elastic modulus of the globule' C-S-H is calculated to assess the elastic modulus of C-S-H phases (the low-density C-S-H - LD C-S-H - and the high-density C-S-H - HD C-S-H), where the porosity is a critical factor for explaining the relationship between globule' C-S-H at nanoscale and C-S-H phases at microscale. Results show that (1) The C-S-H(I) structure has transformed from crystalline to amorphous during the annealing process, Young's moduli in x, y and z directions are almost the same. Besides, the extent of aggregation and aggregation path for water molecules in the structure is different in three directions. (2) Young's modulus of both amorphous C-S-H(I) and C-S-H(II) structures with a size of about 5nm under strain rate of 10(-3)ps(-1) at 300K in three directions is averaged to be equal, of which C-S-H(II) structure is about 60.95GPa thus can be seen as the elastic modulus of the globule' C-S-H. (3) Based on the globule' C-S-H, the LD C-S-H and HD C-S-H can be assessed by using the Self-Consistent Scheme (separately 18.11 and 31.45GPa) and using the Mori-Tanaka scheme (29.78 and 37.71GPa), which are close to the nanoindentation experiments by Constantinides et al. (21.7 and 29.4GPa). %G English %L hal-01771120 %U https://univ-rennes.hal.science/hal-01771120 %~ UNIV-RENNES1 %~ INSA-RENNES %~ LGCGM-INSA %~ LGCGM %~ STATS-UR1 %~ GENIECIVIL %~ UR1-HAL %~ UR1-SDLM %~ TEST-UR-CSS %~ UNIV-RENNES %~ INSA-GROUPE %~ UR1-MMS %~ TEST3-HALCNRS