Gypsum morphological analysis and modeling

When plaster is put in water, a network of needles is spontaneously formed. The morphology of the plaster microstructure have been studied in order to understand precisely its role with respect to its physical properties. Three microstructures of plaster were prepared from different hydration conditions, to obtain three crystal sizes at a given level of porosity. We propose a morphological characterization and modeling of the plaster microstructure by means of simple tools of mathematical morphology. From the use of a two parameters random model of microstructure, the Boolean model, contact properties between the microstructural units made of gypsum needles are estimated, and bounds of the elastic behavior of the plaster are compared to measurements. (C) 2001 Elsevier Science Ltd. All rights reserved.