Mechanical Characterization of a Polyurethane-Cement Hybrid Foam in Compression, Tension, and Shear

The mechanical properties of a polyurethane-cement hybrid foam are investigated. The hybrid foam, based on the combined, synergic use of rigid polyurethane foam and portland cement, was introduced for application in the building field. Thermal and acoustic insulation properties, water vapor permeability, and the fire resistance of the material have been reported in previous works. Here, a broad mechanical characterization including compressive, tensile, and shear tests is conducted according to ASTM standard methods for cellular plastic materials. The compressive tests show a brittle behavior of the hybrid foam, with the maximum strength achieved at large values of strain, compared to concrete. The material exhibits more strength under tension than under compression. The shear resistance values are similar to those of other building materials generally used for nonstructural components, i.e., cellular concrete and bricks. Finally, by comparing the physical properties of the hybrid foam with those of bricks and cellular concrete it is possible to highlight that the lightweight features of the former, associated with appreciable mechanical properties, make it suitable for building nonstructural components, also in seismic zones.