Experimental characterization and numerical modeling of the fracture process in banded Alfas porous stone

The Alfas porous stone (porolithos) excavated in Rethimnon, Crete, Greece, often features two material bands with similar mineralogical but different depositional characteristics and therefore different mechanical parameters. The present study compares the experimental and numerical results for uniaxial compressive tests of the banded Alfas porous stone. Cylindrical specimens with a diameter of 54 mm were prepared and tested in the laboratory. Testing revealed complex failure modes/patterns under uniaxial compressive loading. Experimental tests were simulated numerically using the bonded particle model (BPM) available in the PFC2D code. The PFC2D microparameters of the BPM were indirectly determined, and the experimental fracture load and the failure pattern are compared with the numerical results. The simulation results demonstrate that both the macromechanical response and the failure process can be modeled using BPMs. The strong influence of the weaker band on the mechanical behavior and failure mode of the Alfas porous stone is confirmed. The differences between the numerical results and the macroscopic behavior are discussed.