Influence of the porosity and pore size on the mechanical properties and energy dissipation of cellular concrete utilizing millimeter-size SAP

Super Absorbent Polymers (SAP) cellular concrete is a functional material with a distinctive pore formation mechanism. However, the effect of the mechanical properties, energy dissipation characteristics and failure pattern of cellular concrete under localized stress is not clear, limiting the application of the material. In this study, the effects of porosity (40 %, 50 %, and 60 %) and pore size (2 mm, 5 mm, 8 mm) on the elastic modulus, plateau stress, energy dissipation, and failure patterns of cellular concrete fabricated using a superabsorbent polymer (SAP) and their relationships are investigated using MTS and SHPB. The results show that under static loading, the elastic modulus increases with the enlargement of the pore diameter, exhibiting a pore size effect. The plateau stress is mainly influenced by two factors: pore wall thickness and pore wall bending moment. Moreover, employing the pore size effect model predicts the failure mode under static loading, showing good agreement with experimental results. Under dynamic loading, the yield strength and energy dissipation all have strain rate effects. In terms of energy dissipation density, compared with dynamic loading, the material has better performance under static loading. The research findings facilitate the selection of SAP cellular concrete with diverse pore sizes and porosities according to engineering demands, achieving functional customization.