Mechanical failure mechanisms of hydrated products of tricalcium aluminate: A reactive molecular dynamics study

摘要

Hydrogarnet, ettringite, and monosulfoaluminate are known as the most important hydrated products of tricalcium aluminate, a major phase of ordinary cement with applications as a sustainable binder material. To understand the mechanical strength and performance of this important category of materials under external loads, the atomic structures of them are investigated at the nano-scale in the current study. Through an extensive set of reactive molecular dynamics simulations, the mechanical behavior of the representative crystalline structures is examined under uniaxial tensile strains and the corresponding stress-strain curves are obtained. The effects of strain direction and rate on the stress-strain behavior are particularly investigated. From the stress-strain curves, both elastic response and plastic response of the hydrated phases of tricalcium aluminate are determined. A comprehensive chemical bond and structural damage analysis is also performed to characterize the failure mechanisms under high tensile strains.