title: Standardization of peeling tests for assessing the cohesion and consolidation characteristics of historic stone surfaces.
abstract: A peeling test known as the "Scotch Tape test" has been used for more than 40 years in conservation practice for assessing the consolidation efficiency of degraded stone. However, the method has not been supported by any standard or reliably verified recommendations for its application. Its applicability is overestimated, and its unrestricted use without adequate knowledge and sufficient understanding can lead to non-comparable, non-reproducible and, in many cases, incorrect and severely biased results and assessments. This paper presents the results of a recent study focused on establishing limits for application, reliable procedures and a "standard" protocol for testing the cohesion characteristics of brittle and quasi-brittle materials, mainly mortars and stones. The main application strategy exploits repeated peeling in the same place on a surface in order to eliminate the effect of the natural decrease in the detached material from the subsurface layers, which might be incorrectly interpreted as a consolidation effect. There is a discussion of factors influencing the performance of the peeling test method, and examples of peeling measurements on various natural and artificial stones are presented.
authors.affiliation: Institute of Theoretical and Applied Mechanics of the Academy of Sciences of the Czech Republic, Prosecká 76, 19000 Praha 9, Czech Republic.
authors.forename: Miloš
authors.initials: M
authors.lastname: Drdácký
authors.affiliation: Institute of Theoretical and Applied Mechanics of the Academy of Sciences of the Czech Republic, Prosecká 76, 19000 Praha 9, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Lesák
authors.affiliation: CNR, Institute for the Conservation and Valorization of Cultural Heritage (ICVBC), Via Madonna del Piano 10, 5019 Sesto Fiorentino, Florence Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Rescic
authors.affiliation: Institute of Theoretical and Applied Mechanics of the Academy of Sciences of the Czech Republic, Prosecká 76, 19000 Praha 9, Czech Republic.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Slížková
authors.affiliation: CNR, Institute for the Conservation and Valorization of Cultural Heritage (ICVBC), Via Madonna del Piano 10, 5019 Sesto Fiorentino, Florence Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Tiano
authors.affiliation: Institute of Theoretical and Applied Mechanics of the Academy of Sciences of the Czech Republic, Prosecká 76, 19000 Praha 9, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Valach
keywords: Cohesion; Historic stone; Non-destructive testing; Peeling test; Surface consolidation