Acomputer-basedmodelandmethodwaspresentedtopredictthetimedependencyofchloridediffusioncoefficientsincementpaste.TheHYMOSTRUC3Dmodelwasappliedtogeneratea3Drepresentativeelementaryvolume(REV)ofcementpaste.Inthesimulationofmicrostructure,bothofcementhydrationandchloridebindingwereconsidered.Withthesimulatedmicrostructureofcementpaste,thefiniteelementmethodwasappliedtosimulatethediffusionprocessofchloridethroughthesaturatedcementpaste.BasedontheFick’sfirstlaw,thechloridediffusioncoefficientcanbecalculated.Inthismethod,theinfluencesofageandw/cratioonthechloridediffusioncoefficientwereevaluated.Thesimulatedchloridediffusivitieswithvariousw/catdifferenttimewerecomparedtoexperimentaldataobtainedfromtheliterature.Theexperimentalresultsindicatethatthechloridediffusioncoefficientdecreaseswiththeincreaseoftimeandthedecreaseofw/cratio.Thetrendofsimulatedrelationship(diffusioncoefficientvstime,diffusioncoefficientvsw/cratio)fitsverywellwiththeexperiments.
