Diffusion coefficient and infinitesimal shrinkage strain of a Strain-Hardening Cement-Based Composite (SHCC) determined by inverse analysis of experiments

The moisture transport and drying shrinkage properties of a certain type of Strain-Hardening Cement-Based Composite (SHCC) are investigated. This material is characterized by the usage of short high-modulus polymeric fibers as reinforcement of a cementitious mortar matrix with comparatively small grain sizes. The drying-induced mass loss and length change of circular cylindrical specimens with a radius of 25 mm have been measured. By inverse analysis of the experiments utilizing an evolutionary optimization algorithm, the material-specific transport and drying shrinkage parameters were identified. A sensitivity analysis revealed that the model assumptions concerning the mechanical material behavior, incorporating damage and creep, had only a small influence on the present inverse analysis results. It was also concluded that for the investigated type of material and the chosen geometry, the directly measured steady-state specimen contraction appropriately describes the material-specific drying shrinkage behavior.