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Shock Wave–Induced Dynamic Mechanical Behavior of Calcium Silicate Aluminate Hydrate at the Molecular Scale.
- Source :
-
Journal of Materials in Civil Engineering . Aug2023, Vol. 35 Issue 8, p1-10. 10p. - Publication Year :
- 2023
-
Abstract
- Calcium silicate aluminate hydrate (C-A-S-H) is the main hydration product of cement mixed with industrial wastes. The purpose of this study is to understand the dynamic mechanical behavior and structural transformations of molecular-scale C-A-S-H induced by shock waves. Three C-A-S-H models with Al/Si ratios of 0.0, 0.1, and 0.2 are constructed and reactive molecular dynamics simulations are used to perform shock compressions with different shock velocities from 0.1 km/s to 3.6 km/s. The distributions of particle velocity, pressure, and density along the shock direction are calculated using the binning analysis method, allowing Hugoniot pressure-specific volume curves to be derived. The results reveal that shock waves may induce elastic, elastic-plastic, or shock Hugoniot responses in molecular-scale C-A-S-H, depending on the Al/Si ratio and the shock velocity. Below the Hugoniot elastic limit (HEL), higher Al/Si ratios cause the elastic wave to propagate farther due to the cross-linking effect of aluminate units. Above the HEL, higher Al/Si ratios give rise to a distinct two-wave structure characteristic comprising a plastic front and an elastic precursor. This characteristic becomes less pronounced as the shock velocity increases. Analysis of the molecular structural transformations of C-A-S-H revealed that the main atomic deformation behavior below the HEL involves a reduction of interatomic distances; above the HEL the main response is a densification of water molecules followed by a general collapse of the layered structure as the shock velocity increases. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 08991561
- Volume :
- 35
- Issue :
- 8
- Database :
- Academic Search Index
- Journal :
- Journal of Materials in Civil Engineering
- Publication Type :
- Academic Journal
- Accession number :
- 164352143
- Full Text :
- https://doi.org/10.1061/JMCEE7.MTENG-15003