Experimental analyses for the preservation of trachyte pavings in salt-controlled weathering conditions

The results of an experimental research aimed in characterizing the main properties of trachyte slabs employed as paving in common pedestrian roads and pavements in salt-controlled weathering environment are here presented. The area was subjected to sea-water splashes, and particularly exposed to the sun which provoked differential deterioration phenomena in the slabs, varying from localized cavities to a general surface erosion. Laboratory tests performed at the University of Padova allowed to define preliminarily physical-mechanical and petrographic properties of trachyte samples drawn from different damaged slabs. Simulation of salt crystallization cyclic actions performed on specimen before and after treatment with a siloxane-based compound in organic solvent, considering different interface roughness, provided indications on the possible preservation intervention. Results after tests evidenced that the deterioration phenomenon is strongly connected to the different porosity detected in the stones and that their durability can be effectively improved by the specific treatment proposed.