Sediment management is increasingly oriented towards valorization processes in several fields. Many researches have been conducted on the characterization of sediments and the possibility to be used as raw materials in the field of civil engineering. The overall objective of this contribution is to setup a numerical modeling strategy with a validation on the basis of experimental results. The mechanical strengths (flexural and compressive) and the elastic modulus were investigated. Five mortars were formulated with different substitution of sand by sediments (from 0% to 40%). A numerical model was built using the finite element method (FEM) based on homogenization technique. This model allows the prediction of the global mechanical behavior of the mortars based on the knowledge of the mechanical behavior of each phase constituting these samples. The model was validated through an example of a microstructure of a BOF (Basic Oxygen Furnace) slag from literature work. The microstructure has been observed using Scanning Electron Microscope SEM in order to identify the major phases in presence. Besides, the elastic properties of these phases have been determined using an instrumented indentation technique coupled with SEM. The obtained results show a good agreement between numerical and experimental. The model is validated and can then be applied on the mortars. The mechanical properties of the formulated mortars decrease with the increase of sediment substitution similarly to the obtained results in literature.