Glass bead concrete is an engineered material in which hollow glass beads are introduced into a cementitious matrix to tailor its lightweight and thermal insulation properties. Due to the wide application of glass bead concrete in civil engineering, investigating its thermal and mechanical properties is of important interest. In addition, owing to their well characterized properties with respect to geometry, stiffness and density, glass beads provide an ideal material system for investigating microstructure–fracture interactions under controlled heterogeneity. In this contribution, a coupled experimental and FFT based computational framework, where the approach relies on a variational phase-field formulation with diffusive crack topology, is employed to investigate the fracture behavior and crack initiation mechanisms of glass bead concrete. The Fast Fourier Transform (FFT) based method enables matrix-free iterations, low memory footprint and allows the direct use of voxelized digital microstructures, making it particularly well suited for materials with complex inclusion morphologies. Prior to applications, the FFT solver is validated on well-established two-dimensional phase-field fracture benchmarks, including the single-edge-notched tension test and the perforated plate under compression. These benchmarks allow the FFT-based framework to reproduce peak loads, post-peak softening, and crack localization patterns, in agreement with reference solutions, while maintaining stable convergence in the presence of strong nonlinearity. Next, the experiments have been done to identify material parameters required by the phase-field model and the FFT solver, including elastic properties of the cementitious matrix with and without glass bead inclusions, characteristic length scales and critical energy release rate. Finally, the FFT solver is used to simulate the failure of heterogeneous samples of glass bead concrete and results are compared with the experiments.