Crushing behavior and crushing strengths of low-density foam concrete

Foam concrete is a highly cellularized cementitious material that undergoes extensive plastic deformation when loaded to failure. Under compression, the microstructure of low-density foam concrete gets progressively crushed at a steady stress stage, accompanied by substantial energy dissipation. Understanding foam concrete crushing behavior is of special importance for its engineering applications. However, the current studies are insufficient to define key attributes that are important for material characterization and design. This study focuses on low-density foam concrete ranging from 0.4 to 0.8 g/cm³ (25 to 50 lb/ft³), with the crushing behavior investigated using a penetration test and dynamic Young's modulus determined using a resonant frequency test. Four distinct crushing phases-linear elastic, transitional, plateau, and final densification-are observed for the samples. Furthermore, the yield strength and plateau strength are identified to characterize the foam crushing behavior. Using the experimental inputs, the modulus-strength constitutive relationship is established for predicting the crushing behavior with fundamental material properties. The findings significantly facilitate subsequent foam concrete studies, as well as the engineering design of this material.