Optical coherence tomography for vulnerability assessment of sandstone

Abstract

Sandstone is an important cultural heritage material, in both architectural and natural settings, such as neolithic rock art panels. The majority of deterioration effects in porous materials such as sandstone are influenced by the presence and movement of water through the material. The presence of water within the porous network of a material results in changes in the optical coherence tomography signal intensity that can be used to monitor the wetting front of water penetration of dry porous materials at various depths. The technique is able to detect wetting front velocities from 1 cm s_1 to 10~6 cms-1, covering the full range of hydraulic conductivities likely to occur in natural sandstones from pervious to impervious. © 2013 Optical Society of America