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Early-age cracking in mass concrete structures resulting from thermal stress is a well-documented phenomenon that impacts their functionality, durability, and integrity. The primary cause of these cracks is the uneven temperature rise within the structure due to the exothermic nature of cement hydration. Assessing the likelihood of cracking involves comparing the tensile strength or strain capacity of the concrete with the stresses or strains experienced by the structure. Challenges in evaluating the risk of thermal cracking in mass concrete structures stem from various material and technological factors that influence the magnitude and progression of hydration heat-induced temperature and thermal stress. These complexities can be addressed through numerical analysis, particularly finite element analysis (FEA), which offers comprehensive modeling of early-age effects by considering all pertinent material and technological variables. However, employing FEA poses challenges such as the requirement for numerous input parameters, which may be challenging to define, and the need for specialized software not commonly available to structural engineers. Consequently, the necessity for such advanced modeling, which demands significant time investment, may not always be warranted and should be initially assessed through simpler methods. This is primarily because the definition of massive structures—those susceptible to adverse effects such as cracking due to temperature rise from hydration heat—is not precise. To address these challenges, the authors propose a three-step method for evaluating structures in this regard. The first step involves a simplified method for the classification of massive structures. The second step entails estimating hardening temperatures and levels of thermal stress using straightforward analytical techniques. The third step, reserved for structures identified as having a potential risk of early thermal cracks, involves numerical modeling. The outlined procedure is illustrated with an example application, demonstrating its practicality in analyzing a massive concrete wall constructed on the foundation. [ABSTRACT FROM AUTHOR]

• Corrected massivity factor dictatied the need for careful thermal study of the slab. • The cracking risk in the analyzed slab using 4 analytical approaches was evaluated. • FE computation of the slab enables the precise analysis of the slab behaviour. • The analytical and numerical results were compared with actual mesurements. • Consistent crack widths resulted from analytical and numerical methods were obtained. Mass foundation slabs represent unique structures because of the considerable thermal effects generated by the exothermic reactions of cement hydration that occur during concrete curing. Arising temperature variations in early age concrete generate tensile thermal stresses that may reach values resulting in cracking in foundation slabs. That is why a realistic estimation of early-age thermal loads and induced stresses is essential in engineering science and practice. In this work, several alternative methods that can be used in the assessment of the early age cracking risk have been thoroughly reviewed and discussed. First, a brief review of analytic and numerical methods has been performed to present the possible design-making paths. Next, a real mass foundation slab is analysed using the described analytical and numerical methods, with simultaneous reference to the measurements made during the construction process. Finally, the advantages and weak points of each method are discussed. [ABSTRACT FROM AUTHOR]