Multi‐Scale Strategy to Estimate Elastic Modulus of Blended Cementitious Materials Accounting for Phase Assemblage

ABSTRACT This study presents a multi‐scale homogenization model to predict the evolution of elastic modulus of blended cementitious materials containing supplementary cementitious materials (SCMs), considering thermodynamical phase assemblage. The phase assemblages are calculated using thermodynamic simulations, the results of which are subsequently introduced into homogenization schemes at different scales, including hydration foam, blended cement paste, mortar, and concrete. Recycled brick powder (RBP) and fly ash (FA) are employed as representative SCMs to validate this model. Comparisons with experimental data show that self‐consistent (SC)‐Mori–Tanaka (MT) scheme provides the most suitable predictions at paste scale, whereas the generalized self‐consistent (GSC) scheme yields the best agreement for mortar and concrete. Results further indicate that incorporation of SCMs significantly alters phase assemblage by reducing total hydrate content and increasing porosity, which are identified as the dominant factors governing predicted elastic modulus. Sensitivity analyses demonstrate that water‐to‐binder ratio is the most influential parameter affecting elastic modulus, followed by interfacial transition zone (ITZ) thickness and SCMs’ replacement level, while the influence of the reactive phase content and particle morphology remains limited within realistic ranges. From an engineering standpoint, the proposed framework offers a practical means for preliminary evaluation of stiffness performance in blended concretes and stiffness‐oriented design of sustainable cement‐based materials.