A chemo-thermo-viscoelastic model for early-age concrete behaviors

Abstract

In this study, a novel chemo-thermo-viscoelastic phase field model is proposed for simulating early-age concrete behaviors. The model integrates multiple chemical and physical processes, including hydration reaction, thermal conduction, elastic and viscous deformations, damage, and their interactions. The thermodynamic consistency of these coupled processes is ensured through the first and second laws of thermodynamics. In the model, elastic and viscous processes are described incrementally using the solidification theory, accounting for property evolution during hydration. Damage, coupled with elastic and viscous deformations is modeled with a new viscoelastic phase field framework employing Kelvin-Voigt chains. Additionally, chemo-thermal effects are coupled with deformations through autogenous shrinkage, thermal expansion, and thermal transient creep. The model’s validation is verified through three representative experiments: a creep test, a thermally active restrained shrinkage ring test, and a massive concrete wall cracking test. The simulation results show good alignment with the experimental data.