Numerical investigation of effect of particle shape and particle size distribution on fresh cement paste microstructure via random sequential packing of dodecahedral cement particles

At the microscopic scale, fresh cement paste is composed of random packing of irregular cement particles and their packing behavior plays an important role in microstructure evolution. The characterization of fresh cement paste microstructure is of particular interest in its physical properties, such as mechanical and transport properties. The preponderance of previous work has focused on the microstructure model by random packing of ellipsoidal particles, and little is known about three-dimensional (3D) non-ellipsoidal particles. In this paper, a modified cement particle size distribution function is used to facilitate particle size distribution of dodecahedral particles. Based on a random sequential algorithm, the microstructure model of fresh cement paste is simulated by the random sequential packing of dodecahedral particles with various sizes. Applying stereological tools and a serial sectioning analysis technique, the simulated microstructure composed of multi-sized dodecahedral cement particles is characterized and compared with that of ellipsoidal cement particles developed by the preliminary work to evaluate the influence of cement particle shape on the microstructure of fresh cement paste. Moreover, the random packings of multi-sized dodecahedral particles satisfied with three specified particle size distribution functions, respectively, are investigated to assess the effect of particle size distribution on the random packing of the dodecahedral particles. Finally, the reliability of the statistical results is verified by theoretical solutions.

► The random sequential packing model of dodecahedra is simulated.
► The microstructure of fresh cement paste is characterized by stereological theory.
► Effects of particle shape and PSD on the microstructure are quantitatively evaluated.
► The statistical results are verified by the theoretical results.