Betonda ısı ve rötreden kaynaklı çatlamaların hesaplamalı modellenmesı̇

This work is concerned with the computational modeling of thermal and shrinkage- induced cracking in concrete. Thermal and hygral gradients develop within concrete structures of varying sizes and aspect ratios due to the intrinsic physicochemical phenomena accompanied by adverse environmental effects. These spatio-temporal gradients invariably result in uneven volumetric deformations that can cause stress concentrations when the concrete is sufficiently rigid. Then, when the gained tensile strength is lower than the principal stresses generated by the non-uniform volume changes, cracks will occur and make concrete structures prone to deleterious environmental effects that can cause consequent destructive durability problems. Therefore, predictive computational models are crucial to conduct crack risk analyses not only during the design stage but also during and after the construction of important concrete structures. For this purpose, we develop multi-field computational models to simulate thermal and shrinkage-induced cracking separately. For the former, we developed a novel chemo-thermo-mechanical model coupled with a quasi-brittle phase-field model where the hydration, thermal, mechanical, and fracture problems are solved in a coupled manner. For the drying shrinkage-induced cracking, we de- velop a new coupled chemo-hygro-mechanical model within the framework of poro- viscoelasticity to describe the basic and drying creep of concrete in short- and long- terms. The latter model is further supplemented by a cohesive phase-field model to simulate shrinkage-induced cracking. The capabilities of the proposed models are assessed through the benchmark problems and experimental results reported in the literature.