Relationship between Slipperiness and Other Characteristics of Stones used as Flooring Slabs

Slip resistance is an essential parameter when dimension stones are used as inner and outer floorings. Declaration of performances of stones and their surface finishes (sawn, honed, polished, hammered, flamed, sandblasted, or brushed) in relation to conditions (wet or dry) in Conformité Européenne (CE) marking is essential for pedestrian safety. In this study, 130 samples taken from 81 stone types belonging to 13 types of petrographic families were tested according to the EN 14231 Standard, taking different finishes into consideration, during a ten year period in the Marble Laboratory of Politecnico di Torino (Italy). A high number of pendulum friction tests (1,560) were conducted on 780 samples, and more than 7,000 readings were taken. On the basis of the obtained results, significant relations were found between the tested petrographic families and the types of finishes. A high correlation between open porosity, quartz content, and slipperiness of the stones with honed surface finishes was found. Moreover, the importance of the petrographic characterization of the stone, in relation to the declared surface finish, emerged as each petrographic family responded differently (according to its composition) to the action of the finishing abrasive