PSI - Issue 84

Michele D’Amato et al. / Procedia Structural Integrity 84 (2026) 1175–1182

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The database is organized into three main sections focusing on the strengths of reinforcing steel, concrete, and prestressing steel. For each material, data were extracted from three distinct sources: design nominal values (values retrieved from original drawings and technical reports), acceptance test certificates (mechanical values measured during the structures execution) and in situ tests (values obtained from recent diagnostic investigations). Of the 4899 total records collected on database, 4574 complete entries were utilized for statistical analysis; incomplete records (e.g., those contain only a material's category without the corresponding mechanical properties) were excluded. More in detail, the total records include 3788 records derived from prestressing steel acceptance certificates issued by the Materials Testing Laboratory at Politecnico di Milano, nevertheless the specific final bridge applications for these laboratory samples are not documented. The data collected in the database includes general information about each bridge examined, such as: the region, the province, the road it serves, the construction material of the beams, the year of design, and the reference design standards according to the Italian Bridge Guidelines (MIT, 2020). For each structural element present (e.g., beams, cross-beams, slabs, piers, pier caps, abutments, foundations, box girders, and half-joints), the database stores information regarding each material examined, specifying the data source (e.g., design nominal values, acceptance certificates, or in situ tests). In addition, information regarding the shape, dimensions, and strength characteristics of each material is reported. Specifically, for reinforcing steel bars, the database reports the bar shape (square or circular), diameter or side length, yielding strength (f y ), tensile strength (f u ), and ultimate elongation (A gt ). Concrete data includes information on cube or cylinder dimensions and compressive strength (R c or f c ). While, for prestressing steel, the following parameters are recorded: specimen type (strands, wires, cables, bars, braids, and other types), tensile strength (f ptk ), strength at 0.1% of residual deformation [f p(0,1)k ], strength at 0.2% [f p(0,2)k ] of residual deformation, strength at 1% of total deformation [f p(1)k ], elongation at the maximum strength (A gt ), and maximum allowable stress ( σ s ).

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Fig. 1. (a) Number of bridges analyzed in each region of Italy; (b) bridge typology examined.