Assessment of restoration results on a Sardinian coastal tower

This study reports the results of investigations on the conservation conditions of a Saracen tower, called Torre del Pozzo, located in the South-West coast of Sardinia, subjected to restoration about ten years ago. The tower suffers from serious problems related to inherent vulnerability of the materials with which it was built, in particular biomicritic limestone which constitutes the outcropping rock type in the area and lime mortar with poor physical-mechanical properties. These materials have been over the centuries subjected to particularly aggressive actions by the wind corrasion and disruptive action produced by the crystallization of salts within these porous materials. These actions have produced an intense erosion of the walls with consequent partial collapse of the structure. Essential restoration interventions have been conducted about ten years ago and involved the restoration of the mortars and the replacement and integration of ashlar stone deteriorated. After about 10 years after the intervention, some inspections have been carried out on the site in order to assess the effectiveness of the intervention and the state of preservation of the tower. Repair mortars, applied during the intervention, and biomicritic limestone, which forms the principal building material, have been characterised from a physical-mechanical and micro-structural point of view, in order to assess their condition and durability.