Local porosity distribution of cement paste characterized by X-ray micro-tomography

Porosity is one of the most important parameters for cement-based materials, which influences the mechanical property, transport property, and durability. The spatial and frequency distributions of local porosity of cement pastes are characterized using X-ray micro-tomography data and treating methods. The 3D spatial distributions for three cement paste specimens with different water cement (w/c) ratios show reasonable heterogeneity. The probability analysis also reveals this heterogeneity: the representative volume element (RVE) size based on porosity maps decreases with w/c ratio firstly, then increases with w/c ratio; and the heterogeneity on the characterized probe size or on the RVE size increases with w/c ratio. Average porosities obtained using the CT method are further compared with those by traditional methods.