Numerische Untersuchungen zur Rissentwicklung in Vorsatzschalen bei massiven Wasserbauwerken

Numerical investigations of the crack development in concrete facings for massive hydraulic structures. The repair of existing structures is becoming increasingly important worldwide. This trend also affects the need for renovating massive hydraulic structures. A large share of these restorations involves repairing damaged concrete surfaces. A common approach in these cases is the installation of a reinforced concrete facing. However, the installation of the reinforcement required to limit the crack width in the facing layer is both time-consuming and, consequently, costly. The required reinforcement essentially depends on the development of the hydration heat and the resulting restrained deformations at an early age. This article presents a numerical model to simulate the interaction between the concrete facing and the existing structure, analyzing the stress development during concrete hardening and the subsequent crack formation. A realistic representation of the structural behavior requires the use of suitable models to simulate time-dependent properties such as temperature evolution, strength and stiffness development of the concrete, as well as its time-dependent deformation behavior (creep and shrinkage). The simulation results show that an optimization of the reinforcement for crack width control is possible.