Early-age cracking in mass concrete: Modeling and case study of an extra-large exhibition pool

Abstract

Early-age cracking is one of the most common and challenging problems in the construction of mass concrete structures. This paper addresses the effects of factors such as temperature, hydration, creep, and shrinkage on the time-varying properties of concrete during construction by establishing an energy-based constitutive model for early-age concrete within the framework of continuous damage mechanics. The model comprehensively describes the damage of concrete due to the aging effect related to the degree of hydration, where the mechanical damage is driven by the work conjugated to the elastoplastic damage energy release rates. The thermal evolution during hydration is fitted with a large amount of experimental data, enabling the partial decoupling of multi-factor effects and facilitating the establishment of a sequential thermal-mechanical coupling analysis method. After preliminary verification through restrained ring cracking tests, the proposed model and method are applied to simulate the construction of an actual large-scale Orcinus orca exhibition pool. By predicting and analyzing the worst-case scenarios, the cracking risk, potential cracking mode, and cracking location of the large pool are determined, providing an important basis for practical construction control and optimization. Examples of these strategies include segmented schemes, reinforcement optimization, and the addition of tensile fibers, as well as selecting the best wind speed, environmental temperature, and casting temperature during construction. These efforts provided crucial guidance for the actual construction of the exhibition pool, and as a result, no visible cracks were found in the completed structure.