Assessment of Complex Masonry Structures with GPR Compared to Other Non-Destructive Testing Studies

Abstract

Columns are one of the most usual supporting structures in a large number of cultural heritage buildings. However, it is difficult to obtain accurate information about their inner structure. Non-destructive testing (NDT) methodologies are usually applied, but results depend on the complexity of the column. Non-flat external surfaces and unknown and irregular internal materials complicate the interpretation of data. This work presents the study of one column by using ground-penetrating radar (GPR) combined with seismic tomography, under laboratory conditions, in order to obtain the maximum information about the structure. This column belongs to a "Modernista" building from Barcelona (Spain). These columns are built with irregular and fragmented clay bricks and mortar. The internal irregular and complex structure causes complicated 2D images, evidencing the existence of many different targets. However, 3D images provide valuable information about the presence and the state of an internal tube and show, in addition, that the column is made of uneven and broken bricks. GPR images present high correlation with seismic data and endoscopy observation carried out in situ. In conclusion, the final result of the study provides information and 3D images of damaged areas and inner structures. Comparing the different methods to the real structure of the column, the potential and limitations of GPR were evaluated.

Structural Assessment via Ground Penetrating Radar at the Consoli Palace of Gubbio (Italy)

“…Regarding CH assets, GPR is useful for investigating deformation of hollow piers due to mechanical stress [3], and for studying the signal reflected by objects inside structures such as bridges or viaducts [4][5][6][7]. Moreover, it allows us to analyze the state of conservation of ancient buildings from historical, archaeological, and structural points of view [8][9][10][11][12].…”

GPR Investigations at St John's Co‐Cathedral in Valletta

“…; Santos‐Assunçao et al . ), humidity gradients that can be critical to the stability of a structure (Plati and Loizos ), and hidden features such as doors in the wall and so on. Non‐invasive investigations offer also information on the history of the monuments, possible architectural changes and changes of use as well as restoration works that occurred in the past (e.g., Geraldi, Loperte and Dolce ).…”

Combining ground penetrating radar and seismic surveys in the assessment of cultural heritage buildings: The study of roofs, columns, and ground of the gothic church Santa Maria del Mar, in Barcelona (Spain)

“…Combination of GPR and seismic survey techniques or ultrasonic testing in cultural heritage assessment was successfully utilized to select the zones or the structural elements where further studies might be required. Both techniques were effectively managed to detect damage in possible damaged areas . They were also successfully combined to study the arrangement of materials in constructive elements and in the detection of wet zones .…”