Monitoring the mechanical response of asymmetrically fractured marble epistyles after restoring their structural integrity

An experimental protocol is presented aiming to monitor the mechanical response of restored structural elements of marble monuments. An accurate copy of a typical epistyle of the Athens Parthenon Temple was constructed by experienced technicians of the Parthenon's worksite under a 1:3 scale. It was composed by two asymmetric fragments and it was restored with the aid of three pairs of titanium bars. It was subjected to ten-point bending, in an attempt to simulate uniform loading conditions. Various techniques, both innovative and traditional ones, were used to monitor strains and displacements: Acoustic Emission (AE), Pressure Stimulated Currents (PSC), Digital Image Correlation (DIC), Optical Fibers, clip gauges, dial gauges and LVDTs. The data recorded from all techniques were in very good mutual agreement. What is more important, however, is that the AE and PSC techniques provided clear and mutually compatible data which can be safely considered as indicators of upcoming failures.