Microstructural modelling of cement-based materials via random packing of three-dimensional ellipsoidal particles

Random packing of particles in cement-based materials plays an important role in microstructural evolution. The preponderance of preview work has focused on the microstructural model by the random packing of spherical or twodimensional elliptical particles, and little is known about three-dimensional ellipsoidal particles. In the present work, a new random packing model of three-dimensional ellipsoidal particles was developed to simulate microstructure of cement-based materials. It was based on a novel numerical algorithm for detecting the contact of ellipsoidal particles. The accuracy and reliability of the algorithm were verified by a visualization of the random packing of monodispersed ellipsoidal particles with rigid boundary conditions. According to these numerical algorithms, microstructural model of cement-based materials was constructed by the random packing of polydispersed ellipsoidal particles, of which sizes satisfy a specific distribution. Finally, applied stereological tools and serial sectioning analysis technique, microstructure of cement pastes, composed of ellipsoidal cement particles, was characterized and compared with that of spherical cement particles. (C) 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of Chinese Materials Research Society.