Effect of Water on the Dynamic Tensile Mechanical Properties of Calcium Silicate Hydrate: Based on Molecular Dynamics Simulation

Abstract

To study the effect of water on the dynamic mechanical properties of calcium silicate hydrate (C–S–H) at the atomic scale, the molecular dynamics simulations were performed in uniaxial tension with different strain rates for C–S–H with a degree of saturation from 0% to 100%. Our calculations demonstrate that the dynamic tensile mechanical properties of C–S–H decrease with increasing water content and increase with increasing strain rates. With an increase in the degree of saturation, the strain rate sensitivity of C–S–H tends to increase. According to Morse potential function, the tensile stress-strain relationship curves of C–S–H are decomposed and fitted, and the dynamic tensile constitutive relationship of C–S–H considering the effect of water content is proposed. This reveals the strain rate effect of the cementitious materials with different water content from molecular insights, and the dynamic constitutive relationship obtained in this paper is necessary to the modelling of cementitious materials at the meso-scale.

Influence of High Water Pressure on Static and Dynamic Compressive Strength of Concrete

“…Shen and Xu [22] were in favor that the increase of porosity enhanced the impact of moisture content on strength, proposing a strength-porosity-saturation model based on the Ryshkewitch [23] model. By molecular dynamics simulation, Zhou and Liang [24] concluded that due to water molecular entering the C-S-H structure, the interatomic distance was entrenched, and atomic interactions were weakened.…”

Mechanical improvement of boron nitride nanosheet-reinforced cement paste by multiscale modeling

“… 52 , 53 It is reported that the tensile strengths of pure tobermorite are 2.03 and 2.41 GPa under the tensile strain rates of 1×10 8 and 1×10 9 s −1 , respectively; the tensile moduli of tobermorite are 40.11 and 42.05 GPa under the tensile strain rates of 1×10 8 and 1×10 9 s −1 , respectively. 51 The shear moduli of the BNNS-tobermorite composite are 70.1 ± 3.7 and 73.5 ± 1.8 GPa under the shear strain rates of 1×10 8 and 1×10 9 s −1 , respectively. 7 In view of the insensitivity of mechanical properties of tobermorite-based materials to the low strain rate ranging from 1×10 8 to 1×10 9 s −1 , the strain rate of 1×10 9 s −1 is adopted in the shear tests and the tensile test in MD simulations.…”

“…The mechanical properties of the tobermorite-based material are significantly dependent on the strain rate in MD simulations. For example, the high strain rate results in high mechanical properties of the tobermorite-based material because the material is damaged evenly at several locations, which requires high external work to be done to overcome the interaction between atoms, 51 while the low strain rate has limited influence on the mechanical properties of tobermorite-based materials. 52 , 53 It is reported that the tensile strengths of pure tobermorite are 2.03 and 2.41 GPa under the tensile strain rates of 1×10 8 and 1×10 9 s −1 , respectively; the tensile moduli of tobermorite are 40.11 and 42.05 GPa under the tensile strain rates of 1×10 8 and 1×10 9 s −1 , respectively.…”

Mechanical Properties of Single-Crystal Calcite and Their Temperature and Strain-Rate Effects

“…As with other inorganic materials, the mechanical properties of calcite are affected by temperature and strain rate [54,55]. In order to study the effect of temperature on the deformation behavior, the strain rate was fixed at 1 × 10 8 s −1 but the temperature was changed from 10 K to 100 K, 200 K, 300 K, 400 K, and 500 K. Figure 11 shows the variations of fracture strength, fracture strain, and elastic modulus with temperature along the [010] , [421] , and [42 1] directions.…”