Ornamental granite durability: evaluation of damage caused by salt crystallization

Abstract

The salt crystallization test is used to evaluate damage caused by soluble salts that penetrate stone and subsequently crystallize in its voids (pores or cracks). The present article discusses the findings for four ornamental granites (gris alba, grissal, rosa porriño and rosavel) tested to European and Spanish standard UNE-EN 12370. Since the rocks studied had an open porosity of less than 5%, their weight loss was practically nil. Nonetheless, certain physical properties such as wave propagation, surface roughness and colour were found to vary after testing. The authors feel that durability in such stones should be based not on weight loss alone, but on the other properties mentioned as well, particularly in the case of granite that is to be used for cladding in exteriors.

Keywords

• durability
• ornamental granite
• salt crystallization
• wave propagation velocity
• roughness
• colour