Bohrwiderstandsmessungen, eine neue und standardisierbare Methode zur Bestimmung der Kohäsion von Naturstein: Entwicklung eines Prototypes und dessen Erprobung / Drilling force measurement system, a new standardisa i methodology to determine the stone cohesion: Prototype design and validation

In the field of conservation of monumental buildings actually a standard methodology is lacking, with which it is possible to determine with the same sensitivity and reliability the "stone hardness" both at the superficial surface and at larger depths (few centimetres), both in laboratory and in situ. The use of the drilling resistance to determine the stone hardness is a very recent application and few working outdoor devices exist. The objective of this work is to validate a new and improved system to assess the drilling resistance of stones. The DFMS is portable and a quasi non-destructive device for direct determination of the "cohesion" of stone materials through the determination of their drilling resistance. The best operational features of the prototype have been established together with the assessment of the sensitivity and reliability of the system.