Upscaling concrete properties: A rational approach to account for the material complexity and variability

Life management of electric hydro- or nuclear power plants requires estimating long-term concrete properties on concrete facilities for obvious safety and serviceability reasons. Decades-old structures are foreseen to be operational for several more decades. Operational time-scale is thus far more extended than laboratory test duration. Additionally, tests on rather old concrete can hardly be done again due to the difficulties of finding genuinely representative cement or aggregates and, as far as dams are sometimes concerned, to the large size of the coarse aggregates. In order to estimate long-term mechanical properties upscaling techniques offer an interesting alternative. Two approaches are described in the sequel: 0D analytical and semi-analytical simulation based on homogenisation techniques and 3D numerical simulation.