Characterization, performance and replacement stone compatibility of building stone in the 12th century tower of Dudzele (Belgium)

For restoration and intervention on natural stones in historical buildings, it is important to pay attention to the origin and condition of the original building material. A prominent part of the façade of the 12th century tower ruin of Dudzele (Province of West-Flanders, Belgium) is constructed with buff-coloured limestone which survived almost nine centuries of environmental and anthropological stress. Microscopical research allowed one to identify this stone as Caen stone (France) which is an important historic building material in northern France and Britain. Additional petrophysical tests confirmed this identification. Based on the stone's petrophysical properties and an evaluation of its decay state, criteria for properties of a replacement stone in a similar material could be established.