Determining the weathering classification of stone cultural heritage via the analytic hierarchy process and fuzzy inference system

The greatest factor that threatens the integrity of stone monuments, which are the shared heritage of humanity, is the effects of weathering. This process causes different forms and degrees of deterioration, sometimes in the internal structure of the building stones (crack formation from stress or gap structures after weathering) and sometimes on the visible surface. The accurate definition of the origins, types, and levels of weathering influences and classifications to be created can prevent erroneous intervention in conservation practices. This study creates an integrated weathering classification (IWC) to identify the levels of weathering that are and/or are not seen with the naked eye in building stones. For this purpose, two different weathering classifications are produced with visual analysis and P-wave velocity data, which are methods of non-destructive examination that have been frequently used, particularly in recent years. The IWC is created with the help of the Mamdani fuzzy inference system, which facilitates collective evaluation by eliminating the definitive boundary limits in these classifications. The recommended model is tested at the Ater Baz-i Veli Mausoleum. Among the 146 block stones in the structure, 91 were in the very slight weathering category, 72 were in the slight category, 32 were in the high category, and six were in the very high category. This IWC is presented as an innovative methodology that can produce swift and repeatable results without damaging monuments and serve as an integrated approach in the weathering classification of building stones (internal and external levels of weathering). (C) 2020 Elsevier Masson SAS. All rights reserved.