Integration of ground-penetrating radar, ultrasonic tests and infrared thermography for the analysis of a precious medieval rose window

Abstract

Abstract. The integration of high-resolution, non-invasive geophysical techniques (such as ground-penetrating radar or GPR) with emerging sensing techniques (acoustics, thermography) can complement limited destructive tests to provide a suitable methodology for a multi-scale assessment of the state of preservation, material and construction components of monuments. This paper presents the results of the application of GPR, infrared thermography (IRT) and ultrasonic tests to the 13th century rose window of Troia Cathedral (Apulia, Italy), affected by widespread decay and instability problems caused by the 1731 earthquake and reactivated by recent seismic activity. This integrated approach provided a wide amount of complementary information at different scales, ranging from the sub-centimetre size of the metallic joints between the various architectural elements, narrow fractures and thin mortar fillings, up to the sub-metre scale of the internal masonry structure of the circular ashlar curb linking the rose window to the façade, which was essential to understand the original building technique and to design an effective restoration strategy.

Ground Penetrating Radar Applied to Monumental Stone Conservation: Application to the Rock Necropolis of San Vítor de Barxacova in NW Spain

“…In Leucci et al (2007), a GPR survey conducted with 1 GHz and 1.5 GHz antennas has revealed the existence of fractures in some columns of the crypt of the Cattedrale di Otranto (Apulia, Italy). In Masini et al (2007) and Nuzzo et al (2010), GPR investigations are included to evaluate the state of preservation of the thirteenth century rose window of Troia Cathedral (Apulia, Italy). The GPR survey was performed using 1.5 GHz and 900 MHz antennas, providing relevant findings such as fractures, iron bolts, and internal structure of the ashlar curb linking the rose window to the façade.…”

Microgeophysics and geomatics data integration reveals the internal fracturing conditions of the statue of Ramses II (Museo Egizio, Torino, Italy)

“…Between the available methods, ground-penetrating radar (GPR) and ultrasonic techniques have largely demonstrated their applicability for the detection of fractures and weaknesses in stone artworks. The two methods have been coupled in several studies for the screening of structural and ornamental elements in historical buildings 6 – 10 . In GPR data, fractures can show different signatures depending on their orientation, geometry and filling materials 11 – 13 , e.g.…”

IRT and GPR Techniques for Moisture Detection and Characterisation in Buildings

“…Moropoulou et al [ 44 ] corroborate the results of IRT and GPR while analysing a monastery, as for example in the discontinuity at the interface of two walls. Nuzzo et al [ 45 ] present the results on the rose window of a cathedral affected by widespread decay and instability problems caused by an earthquake. The determination of the internal structure of the circular ashlar curb and the presence of cracks in the columns and calcarenite elements with intersecting arches, as well as of the boundaries between original and restored parts, is possible with the GPR survey.…”