Geo-electrical techniques as a non-destructive appliance for restoration purposes

摘要

The use of geo-electrical survey techniques for restoration purposes proved useful as a non-destructive tool for the diagnosis of a deteriorated masonry structure. A short overview of the development of the technique is given, starting with apparent resistivity maps and continuing with the relative difference maps. In the recent past new developments in geophysics were adapted and implemented for the conditions of masonry structures. The measurements are carried out to construct a pseudo-section, which is the graphical representation of the apparent resistivity values for a 2D-section of the wall. Inverse modelling enables to reproduce the resistivity distribution in the masonry structure that matches with the obtained data of apparent resistivity. Two on site measuring campaigns are presented in this paper. Finally, to parallel actual research areas are elucidated. The aim is to combine an automated measuring system with AC-current power supply creating realistic expectations for the on-line validation of mortar injections in the near future.