Akademik Veri Yönetim Sistemi
Engineering Fracture Mechanics, cilt.289, 2023 (SCI-Expanded)
The manuscript is concerned with the phase-field modeling of thermal cracking in massive hardening concrete structures. Owing to the exothermic reactions, known as hydration, a considerable amount of heat is generated during the setting and hardening of concrete. Since concrete has relatively low thermal conductivity and fairly high heat capacity, sharp temperature gradients may occur between the interior and exterior parts of massive concrete structures. This uneven temperature distribution results in a non-uniform thermal expansion that, in turn, may lead to thermal cracking in conjunction with restraining external boundary conditions. Hence, it is of key importance to conduct the crack risk assessment of massive concrete structures at various stages of their construction and thereafter where real-size experiments are often unrealizable. To this end, we develop a multi-field computational approach to simulate thermal cracking in hardening concrete. In particular, we propose a novel chemo-thermo-mechanical model developed within the framework of the theory of reactive porous media coupled with a quasi-brittle phase-field regularized cohesive zone model to explicitly account for the initiation and propagation of thermal cracks. In the model, chemical, thermal, mechanical, and phase-field fracture problems are coupled through the constitutive equations. To our best knowledge, this is the first study where a quasi-brittle phase-field fracture model is used to model thermal cracking in hardening massive concrete through a novel incremental formulation. The potential of the proposed approach is demonstrated through the benchmark thermomechanical problems of a normal concrete member and a roller-compacted concrete dam. In the latter, original multi-field interface elements are devised between the lifts.