Hardening stresses are generated as concrete hardens when the volume shrinkage of the concrete mortar is restrained by the aggregates. In the early stages of concrete curing, random cracking tends to occur because the structural strength of a concrete structure is relatively low and is likely exceeded by the concrete shrinkage-induced hardening stress. This is the primary cause of the initial damage in concrete. To investigate the initial damage in concrete, an exponential model for strain hardening is combined with a spline interpolation method to characterize the anisotropic hardening process in a three-phase structure that consists of aggregates, cement mortar and an interfacial transition zone (ITZ). A nonlinear analysis using a stress/strain softening damage model is then performed to analyze the characteristics of the shrinkage-induced initial damage in the concrete and the influence of the aggregates on the structural damage. To calculate the magnitude of the initial damage in concrete, damaged and undamaged concrete specimens are subjected to uniaxial loads. The results show that the shrinkage-induced damage initiates at the surfaces of aggregate particles and in the ITZs and then propagates into the cement mortar. The initial damage to the concrete is influenced by the volume fraction and geometric characteristics of the aggregate. These characteristics are analyzed using a random aggregate model and compared with computed tomography images of a cross section of concrete.

During the construction of concrete ship locks, prolonged interruptions between the casting of the floor and lock wall are inevitable. In terms of mass concrete, long placement delays are one of the major reasons for the presence of cracks in newly placed concrete. Therefore, this study examines both the placement and structural characteristics of ship locks after long casting interruptions based on the mass concrete thermal stress theory to determine the major causal factors for cracks in newly poured concrete. Specifically, a block placement method is proposed to reduce thermal stress in newly placed concrete, and the temperature control and crack prevention capacities of the proposed method are verified using the finite element method. The development of the structure’s thermal stress under different temperature control measures is analyzed, finding that thermal stress in the lock walls can be effectively reduced by 50% through low‐temperature block casting. The results demonstrate that the proposed method can significantly reduce the internal thermal stress of newly placed concrete after prolonged casting interruptions, thereby highlighting its applicability for achieving effective temperature control and crack prevention in concrete ship locks.

The internal mesoscale pore characteristics and permeability of concrete determine the complexity of its structural deformation under water pressure. In this study, the change of pore-water pressure and its influence on the deformation of concrete structures are analyzed at the mesoscale. Concomitantly, the stress–strain relationship of pore water is proposed based on the pore-water pressure caused by water seepage. The results indicate that the concrete structure is initially in a compressed state under water pressure, which gradually expands as a function of the seepage of high-pressure water. The deformation of the concrete structure lags behind the external water pressure changes, particularly when the water pressure is increased. The rules and mechanisms of the influence of pore-water pressure on the structural deformation of concrete can be determined based on the method described above.