[en] Our aim is to refine the current description of the leaching phenomenology with cross-linked characterizations of Bituminized Waste Products (BWP) in contact with water, at the early stages of the leaching as well as the longer ones. For that sake, three model BWP have been synthesised, varying the chemical content of salts and the grain size distribution. Water sorption, ¹H CPMG NMR techniques are the main techniques used for this study. They have been compared to the kinetics of water uptake in leaching experiments. These results put into evidence the effect of insoluble salts in the water uptake kinetics. This effect may be attributed to a percolation mechanism enhanced with the presence of small hydrophobic salts. This is really new but has to be deeper evaluated before updating long term predictive modeling of BWP leaching, since we have not at that time correlated this effect with the salts release kinetics