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The determination of abrasion resistance according to EN 14157 'Natural stone test method-determination of abrasion resistance' is required for the CE (European conformity) marking on natural stones. A great deal of abrasive material is necessary for this test, which makes it relatively costly. Furthermore, Boulonnaise marble, the reference stone, is not easily available. The study reports the assessment of Canaloni (Carrara) marble as an alternative reference material using the Capon apparatus, which demonstrates its suitability for this purpose. An evaluation was also made of the effectiveness of the abrasive material (carborundum) after it has been used for the three times stated in the Standard and it was found that its performance remains unchanged, even after a higher number of tests. [ABSTRACT FROM AUTHOR]

Abstract: The bowing phenomenon is frequently a problem for newly constructed buildings, where marble slabs used in façades are usually very thin and have a high slenderness ratio. This kind of rock weathering can mainly be attributed to the intrinsic properties of the slab (petrography, dimensions), the anchorage techniques and the climatic conditions. Previous studies investigated marble with an equigranular-polygonal microstructure (granoblastic) and show they have a higher tendency to bow than those composed of anhedral (irregular) grains surrounded by subgrains (interlobate textures). The aim of this research was to study the correlation between the decrease in mechanical properties and the bowing in three types of marble with different textures and petrographic characteristics. This has been achieved through measurements of the bowing and the flexural strength, the water absorption and the ultrasonic pulse velocity at different stages of artificial ageing. As far as the granoblastic marble, with the progress of the artificial weathering, the tendency curve of bowing shows a sharp initial rise which subsequently proceeds more slowly. At the same time all the three types of marble (including xenoblastic marble, not subjected to bowing) showed a loss in mechanical resistance. Moreover, the flexural strength values matched well with the results of the non-destructive tests. [Copyright &y& Elsevier]