A probabilistic numerical modelling of a roller compacted concrete (RCC) dam construction is proposed by accounting for some uncertainties related to material properties. Probabilistic tools are applied in order to propagate uncertainties and perform a sensitivity analysis with the aim to improve the understanding of how input uncertainties will affect the output variability. A thermo-chemo- mechanical model is used in order to simulate the RCC behaviour The model couples the chemical hydration reaction at early ages with the mechanical properties evolution by introducing an ageing parameter. The sensitivity analysis is carried out using the RBD-FAST test. Temperature, hydration degree, ageing degree and cracking index outputs are assessed.