Blind comparison of saturation ratio profiles on large RC structures by means of NDT and SFE—Application to the VeRCoRs mock-up

The prediction of large concrete structures behaviour such as bridges, dams and nuclear containment buildings (NCB) is a vital issue regarding the evaluation of the durability, safety and effect on the surrounding environment. In this work, experimental and numerical estimations of the saturation ratio profiles in the VeRCoRs NCB mock-up structure are presented, and their blind comparison is discussed. Non-destructive testing (NDT) based capacitive measurements are processed to quantify the saturation ratio experimentally. Then, a weakly coupled thermo-hydric (TH) finite element model is presented within the serviceability state of VeRCoRs for the numerical counterpart. The uncertainty in the capacitive measurements and the constitutive parameters of the numerical model are highlighted as coming from the following three sources: (a) the natural randomness of the material properties and physical processes, (b) the limited knowledge of some input parameters in the mathematical model either obtained experimentally at the specimen scale and (c) empirically derived in the exploitation of the physical process. The influence of the uncertainty in the saturation ratio estimations is presented by error bars experimentally and is addressed by a stochastic finite element (SFE) study in the numerical work. Accounting for uncertainties in NDT and SFE measurements, the mean values of saturation ratio (reported in %) profile are forecasted up to 40% and 34% respectively, with standard deviation for both in the range of 3.5–4.5% in magnitude. •Estimation of the in-situ saturation ratio in the VeRCoRs nuclear containment buildings (NCB) structure using non-destructive capacitive measurements•Suggestion of a weakly coupled Thermo-Hydric (TH) modelling strategy of large concrete structures’ behaviour.•Use of realistic in-situ TH boundary conditions around an operating NCB.•Analysis of the effects of spatial and temporal variation of TH boundaries on concrete saturation ratio in NCBs.•Uncertainty quantification of the TH model parameters by surrogate model-based probabilistic sensitivity analysis.