Decomposition of the Hierarchical Variability of Concrete Random Fields and Its Influence on the Hysteretic Behavior of Structural Components

Due to factors like heterogeneity, curing conditions, and production processes, concrete in structures exhibits hierarchical variability and spatial correlation. However, in engineering practice, when considering the randomness of concrete, the overall variability of a certain strength grade is usually adopted. In this method, the hierarchical structure of concrete is overlooked and the variability of concrete is usually overestimated. To this end, based on the hierarchical model, the variability of concrete compressive strength in component is decomposed into two parts: intracomponent variability and intercomponent variability. The intracomponent variability denotes the spatial variability of concrete in component. The intercomponent variability denotes the variation of the mean values between components. The effect of the variability of concrete is studied by the hysteretic performance analysis of a RC shear wall. The results demonstrated that the spatial variability of concrete has nonnegligible influence on the failure mode and hysteretic behavior of the U-shaped shear wall. When the spatial variability is considered by the identical probability distribution, all samples experienced severe compressive damage. But if the spatial variability is considered by the hierarchical model, samples with both severe and minor compressive damage will occur. In addition, the major compressive damage of the concrete in some samples may transfer to the upper weaker areas of the random field.