On Science Aspects of Simulating Practical Manifestations of Concrete

Abstract

Materials science aspects are discussed that govern manifestations of concrete produced by computer simulation (=compucrete). Stochastic heterogeneity is linked up with scatter in a descriptor of material structure or of performance. Sample size leading to an acceptable scatter level in the descriptor defines the size of the representative volume element (RVE) that is homogeneous as to the very parameter. The RVE size increases with the degree of configuration-sensitivity of the descriptor of structure, or with the degree of structure-sensitivity of the descriptor of performance. In cases of finite degrees of sensitivity, the descriptor's probability density function (histogram) is skew to the left. This causes biases due to stochastic heterogeneity effects in sub-RVE experimental or computer-simulation designs. Physical modelling is performed differently by RSA-based systems, like HYMOSTRUC 3D, and by concurrent algorithm-based systems, like SPACE. Manifestations of concrete produced by RSA-based systems provide only a realistic representation of material composition, whereas the representation of reality also encompasses material configuration in case of concurrent algorithm-based systems. Only the latter type can be used therefore to study structure-sensitive performance characteristics (or configuration- sensitive features).