Phase field fracture simulation of early-age concrete based on chemo-thermo-hygro-mechanical theoretical framework

Abstract

During the curing stage, early-age concrete is highly susceptible to multi-field coupling effects, resulting from chemical, thermal, and humidity changes influenced by hydration. These transformations lead to notable non-load-induced deformations, such as expansion and contraction. Under constrained conditions, this process generates substantial tensile stresses, making early-age concrete prone to cracking. The defects in the early stages of vital civil engineering structures and infrastructure pose a potential threat to their integrity, durability, and safety throughout their service life. To accurately predict the early-age crack resistance of early-age concrete, there is an urgent need for research on modeling and analyzing fracture behavior under chemo-thermo-hygro-mechanical fields. Recognizing this need, this paper incorporates the multi-field coupling phenomenon observed in early-age concrete and utilizes phase field theory to propose a fracture model within this theoretical framework. By applying the model to various numerical examples, it reveals the intricate mechanisms behind cracking induced by hydration, temperature, and humidity in early-age concrete. This enables precise simulation and prediction of the entire crack evolution process. Furthermore, our study highlights a dynamic interplay between structural and convective boundary conditions in crack development, demonstrating the model’s potential to predict complex crack patterns. Through this work, we’ve made significant progress in improving the prediction and control of early-age cracks in concrete structures. The insights gained from this research hold tremendous promise for advancing the field and ensuring the durability and integrity of infrastructure.