I Multi - Scale Digital - Image - Based Modelling of Cement

Computer modelling of the properties and performance of cement-based materials is complicated by the large range of relevant size scales. Processes occurring in the nanometer-sized pores ultimately tiect the performance of these materials at the structural level of meters and larger. One approach to alleviating thk complication is the development of a suite of models, consisting of individual digjtal-image-hazed structural models for the calcium silicate hydrate gel at the nanometer level, the hydrated cement paste at the micrometer level, and a mortar or concrete at the millimeter level. Computations performed at one level provide input properties to be used in simulations of performance at the next higher level. This methodology is demonstrated for the property of ionic diffusivity in saturated concrete. The more complicated problem of drying shrinkage is also addressed.