This thesis presents a numerical analysis aimed at limiting thermal cracking in concrete during hydration, a prevalent issue in large concrete structures. The study focuses on an underground culvert in the port of Narvik, Norway, where concerns about thermal cracking have been raised due to the structure’s size and the desire to minimize such defects. The research employs finite element method simulations to compare various interventions against a base model to determine their effectiveness in reducing thermal cracking.

The study begins with a literature review on numerical methodologies and simplified analytical methods for assessing thermal cracking risk. A finite element software model is calibrated using experimental data on heat development in concrete structures during hydration. A base model, adhering to Eurocode 2 standards, serves as a reference point for evaluating different interventions in other models which includes reinforcement amount, casting segment length, and adjacent concrete temperature.

The results from the finite element models are presented and notable properties are presented. The thermal development for the different models are presented as well as the mechanical analysis which looks at the stress distribution, as well as crack propagation during the hydration. Findings showed a significant increase in the propagation of through cracks between 30 to 110 hours after pouring. This project also concluded that considerations for the dilation joint are more important than that of adding more reinforcement or increasing the temperature of adjacent structure. Although those interventions were not without effect.

The thesis concludes with a discussion of the simplifications made, the precision of the model, and the impact of interventions on thermal cracking. Recommendations are provided for improving resistance to thermal cracking for the case study object, with the understanding that results are specific to the study object and should serve as guidelines for similar structures. Parameters that could have an effect but were not included in this project are discussed and lastly, a conclusion and recommendations for future works are made.