Mura civiche in Piazza Fiera di Trento. Il progetto di restauro e i primi dati di cantiere

The city walls of Piazza Fiera in Trento have been the object of interest of the municipal administration since 2001, when the surveys and observations on their state of consistency began, given the evident importance of the artefact for the urban history and its increasing degradation. The foundations were therefore laid for its knowledge, studying its texture and materials, construction methods and transformation, to probe its structural efficiency and possible vulnerabilities and to plan an adequate conservation scheme over time. The pre-work-site activities were aimed to collect the information necessary for drafting the restoration project: a constructive-stratigraphic survey of the wall faces was drawn up, with in-depth diagnostics on the mineralogical-petrographic nature of the mortars, as well as the recognition of surface biodeteriogens, black crusts and patinas to supplement the macroscopic mapping of the pathologies of the degradation found. The 2007 project was drawn up as a co-work by arch. Bruschetti and arch. Doglioni.The restoration was financed with resources from Article 1, Paragraph 349, Law No. 234, 30 December 2021 (Culture Fund). The restoration site, directed by arch. Gentilini, spans over two years. Works began on the southern elevation. The treatment with a biocide product, the removal of the upper plants and biodeteriogens, the removal of the large areas of cement grouting, and the cleaning of the constituent materials allowed for an unrestricted reading of the morphological-stratigraphic characteristics of the facing, thus permitting a comparison with the data collected during the design phase. The campaign of diagnostic investigations on the mortars was also extended, using mass spectrophotometry for the dating of the calcinarols present in the ancient aerial lime mortars. With all the data collected, it was possible to proceed in the consolidation operations and in the repair of the degraded mortar joints ‘consistently’ with the construction itself.