Mesoscopic simulation of the mechanical behaviour of foam concrete subjected to large compressive deformation

Abstract

As an energy-absorbing material, foam concrete has gained recent application in tunnel support systems. Despite its capacity for substantial compressive deformation, including stress plateau and densification, limited research has delved into this aspect. This study investigates the stress-strain characteristics, fracture behaviour and energy absorption capacity of foam concrete, with a focus on the contact behaviour between its pore structures during large compressive deformation. Through experimental and numerical research, it was found that foam concrete retains compressive strength after reaching the peak stress, with stress levels showing recovery and increase during compression. X-ray computed tomography (X-CT) was utilised to acquire the mesostructured and perform mesoscopic simulations of foam concrete. The experimentally obtained stress-strain curves were used to validate the numerical model. The study discusses and compares mechanical properties and energy absorption capacity of foam concrete with different porosity conditions subjected to large compressive deformation, highlighting the effects of the pore structure and contact property on the densification behaviour of foam concrete. Overall, this research contributes to a deeper understanding of the mechanical behaviour of foam concrete subjected to large compressive deformation.