Characterization and influence of the ancient mortars on the decay of medioeval castle of Barisciano, L’Aquila (Italy)

The fortified architecture in the Abruzzo region has a great historical and cultural relevance; the density of constructions, more than 700 castles, yields economical and methodological difficulties of conservation and use. In the paper a methodology is proposed for the castel of Barisciano to understand and quantify the different stages of structural breakdown; the decay of the masonry is correlated with the charateristics of the mortars. The samples were characterised by means of light microscopy, XRD, SEM-EDS and durability tests (cristallization and freezing–thawing). The lime mortars have local carbonatic aggregates of great dimensions (Dmax=63±7 mm) that produced a low workability, poor adhesion characteristics as well as shrinkage phenomena. The salts content is low (5.01% to 8.43%) and the durability of the mortars is satisfactory. In conclusion, the decay and the breakdown seem to be correlated with the difficulties of the ancient costruction yard and in particular with the finding of the raw materials and with the manufacturing of the mortars.