Ultrasonic Evaluation of Mechanical Properties in Heritage Buildings Constructed with Cordoba Freestone

A fundamental physical and mechanical characterization was performed on the natural stone utilized in the Mosque of Cordoba, Spain, using samples from the designated restoration quarry. The experimental investigation encompassed density measurements, Ultrasonic Wave Propagation Velocity (UWPV), uniaxial compression, indirect tension (splitting), and three-point bending tests on over 100 specimens. The study confirmed the stone’s isotropic nature and lack of significant sample size effect within the tested range. Key quantitative results include a mean uniaxial compressive strength of approximately 6 MPa and the establishment of predictive relationships. A strong linear correlation (R2=0.86) between UWPV and compressive strength was identified, supporting the use of Ultrasonic Test for in-situ evaluation. Compressive strength was also strongly correlated with flexural strength (R2=0.95), whereas its correlation with tensile strength was moderate (R2=0.31). This research delivers crucial reference values and validated correlations for the stone, directly informing structural analysis and conservation strategies for this UNESCO World Heritage site.