Abstract:
Over the past several years, digital-image-based computer models and subsequent visualization of microstructure have proven valuable in studying processing-microstructure-property relationships in cement-based materials. This paper reviews the computer modeling techniques used to simulate the microstructure of hydrating cement paste at the micrometer level and the microstructure of concrete and mortar at the millimeter level. In the former case, digital-image-based models using cellular automata offer many advantages in simulating the reactions occurring during the hydration of cement paste. In the latter case, a continuum hard core-soft shell percolation model appears to be most efficient for modeling the aggregates in a mortar or concrete, each surrounded by an interfacial transition zone (ITZ). Here, digitization is employed to compute the volume fractions occupied by aggregate, bulk cement paste, and ITZ cement paste. The influence of microstructure on the diffusivity of these materials is addressed within the overall framework of this multiscale modeling approach.
