Published online by Cambridge University Press: 28 February 2011
A non-destructive ultrasonic procedure has been developed for evaluating in-situ the relative deterioration of monumental stones. Ultrasonic waves are injected into the rock and they are registered, processed and petrophysically interpreted after travelling through it. The procedure applied to a Spanish Monastery (San Lorenzo de El Escorial, Madrid) built with a granitic rock is described.
The following methodology was applied: in-situ categorization of the observable deterioration forms, sampling in the original quarries, laboratory ageing tests and continuous ultrasonic monitoring, in-situ data acquisition, evaluation of the ultrasonic parameters by signal processing and stepwise discriminant analysis. All that information is petrophysically interpreted for an appropriate assignation of the in-situ studied masonry blocks to the categorized deterioration degrees.
Final in-situ results from the Monastery of El Escorial are here presented. Among the studied ultrasonic parameters energy is the most useful of all of them and velocity the least.