Damage of marble from cyclic loading

The behavior of marble was investigated to evaluate the damage and failure mechanisms produced from cyclic loading. Approximately 100 cycles of increasing load steps, representing low cycle fatigue, were imposed on beams in three and four-point bending. Damage was recorded through an array of strain gauges and an interferometric technique that provided a full-field assessment of the surface deformation. It was shown that large strains in the marble beams created permanent deformations that, with cyclic loading, collected in an irreversible way with a progressive loosening of the calcite grains. The failure surfaces of the specimens under monotonic and cyclic loading were visually different in that macroscopic fracture of cyclically loaded specimens were covered with powder, revealing the decohesion process. Permanent elongation was measured at the bottom of the beams, while shortening appeared at the top. This permanent deformation is characteristic of a bowing type of behavior that has been observed in thin marble cladding damaged from weathering.