Mechanical properties of basalt fiber foam concrete based on microscopic numerical simulation

To explore the pore characteristics and uniaxial compression mechanical properties of basalt fiber reinforced foam concrete (BFRFC) with varied densities and fiber mixtures, this study carries out X-ray computed tomography (X-CT) and uniaxial compression tests on samples featuring three types of fiber mixtures at two different densities. It examines the pore and fiber distribution within these samples and leverages MATLAB to develop a three-dimensional reconstruction model of BFRFC's microstructure. Additionally, a progressive damage model, grounded in Hashin's failure criteria and damage variables, has been formulated. The uniaxial compression test simulations were executed using Comsol's finite element software. The findings indicate that BFRFC's pore diameter follows a lognormal distribution. Notably, both porosity and average pore diameter exhibit a decrease with increasing density and fibre content; within BFRFC, the polar angle of the fibers predominantly ranges from 15° to 90°, whereas the azimuthal angle is uniformly distributed across 0° to 360°. The microstructure-based simulation model of BFRFC, integrated with the progressive damage model that accounts for the material's softening characteristics, proves effective in simulating the material's progressive damage. Furthermore, the microstructure-based simulation model, when coupled with the progressive damage model that considers the softening traits of the material, accurately simulates the uniaxial compression behavior of BFRFC. The incorporation of basalt fibers into BFRFC notably enhances its mechanical properties, such as peak strength and energy absorption capacity. Moreover, during the uniaxial compression process, the material's mechanical response is progressively relayed from the outer to the inner layers, enhancing its structural integrity and resilience.