Application of non-destructive evaluation and signal processing for diagnosis of historic heritage buildings

Abstract

[EN] In this work, signal processing techniques are combined with non-destructive evaluation (NDE) to evaluate the capability for detecting defects in historic walls. To join this aim, ashlar masonry walls of 3x2x0.2m have been made at laboratory facilities with controlled and localized defects. These scale walls have been inspected by means ultrasound and ground penetrating radar (GPR) with loads of different weights (0Tn, 10Tn, 50Tn and 80Tn). The ultrasonic and GPR signals provided tomographies that have been improved by means processing techniques. Related to ultrasonic tomographies, kriging algorithm have been implemented for visualization improvement. By the other hand, novelty differential tomographies have demonstrated their sensibility to defects. Related to GPR, different algorithms have been developed to improve the tomographies: elimination of the background noise, depth resolution enhancing and automatic detection and correction of hyperbolas due to radiation pattern of the antenna. Finally, it is concluded the added value of signal processing applied to NDE for the detection of defects in historic walls.