Scaling of nanoscale elastic and tensile failure properties of cementitious calcium-silicate-hydrate materials at cryogenic temperatures: A molecular simulation study

Abstract

This paper investigates the scaling of the nanoscopic elastic and tensile failure properties of calcium-silicate-hydrate (C-S-H). We report a Zhurkov-like scaling behavior for disordered C-S-H of various compositions at cryogenic temperatures, using molecular dynamics simulations. To this end, we first propose a revised molecular construction route to generate C-S-H atomic configurations with varying compositions. Then, we investigate how the tensile behavior evolves with temperature, system size, and strain rate. Our simulation results show that tensile strength, Young's modulus, fracture energy, and fracture-process zone (FPZ) length, all follow a Zhurkov-like scaling law providing a general temperature-size-time equivalence. Such scaling laws make it possible to extrapolate molecular simulation results to larger length and/or time scales. Detailed analysis shows that the typical FPZ length of C-S-H is about 150 Å, and the maximum reduction of activation energy barriers for tensile failure is 0.497 and 0.446 eV for Ca/Si of 1.7 and 1.1, respectively.