A novel explicit modelling framework based upon correlated random field and level-set methods is presented and applied to cement paste hydration. Focus is then made on effective diffusive properties prediction through numerical homogenisation, using the Lattice Boltzmann method, exploring the stability limits and performance of this method for heterogeneous media. Une méthode originale de création de morphologies de pâtes de ciment en cours d’hydratation à l’aide d’excursions de champs aléatoires corrélés est introduite. On présente ensuite le calcul des propriétés diffusives effectives homogénéisées de ces pâtes à l’aide de la Méthode de Boltzmann sur gaz réseau, les limites de stabilité et de performances associées à cette méthode pour les matériaux hétérogènes, ainsi qu’une application aux pâtes de ciment en cours d’hydratation.

Mesoscale analyses of cracked porous volumes are performed. The fluid flows through a multiphase volume comprising one macro-crack, macro-pores and random micro-porous solid inclusions. Mesostructures are defined by thresholding of spatially correlated Gaussian random fields.Transport through macropores and crack, as well as the diffusion in micro-porous solid inclusions, are taken into account. Homogeneous (without cracks) porous volumes illustrated the asymptotical behaviors. The corresponding macroscopic permeability tensors are obtained and correlated with the geometrical/statistical properties of the analyzed porous systems. A new equivalent electrical scheme, including shunt resistance, is proposed to evaluate the apparent diffusion coefficient. Macro-cracked porous volumes are then investigated.The increases in mass flux due to the crack, as well as the mass/energy exchanges with the surrounding porous medium, are quantified by direct numerical simulation. A drying region due to the macrocrack was illustrated and the corresponding apparent permeability was identified. For different geometrical configurations (macro-porosity, micro-porosity, macro-crack orientation and aperture) we quantify the macropore –crack interlink by comparing such structure with structure without possible flow between the macro-crack and the porous structure.The equivalence scheme between mass flow in cracked porous media and heat flow in porous media was underlined.

Le renouvellement d’air est un facteur déterminant du comportement thermique dynamique dans les bâtiments ventilés naturellement ou les espaces semi-ouverts comme les gares. Cependant, dans les approches classiques de modélisation, les pressions en façade sont généralement données par des corrélatio