Quality Control of Prestressed Concrete Girder Decks in Existing Bridges: From Diagnostics to Numerical Analysis

The inherent aging of existing bridges together with adverse surrounding environmental conditions that have accelerated material degradation phenomena emphasize the need of a comprehensive quality control and management system of the Italian roadway bridge stock. In this context, this paper presents a procedure oriented to a comprehensive quality control and structural safety assessment of prestressed concrete (PC) girder decks in existing bridges. The proposed procedure combines experimental material characterization, field tests in serviceability conditions (static load tests and free vibration tests) and numerical simulation through a finite element model of the PC girder deck (linear and nonlinear analysis at ultimate limit states). The procedure, which is here illustrated in the context of a case study represented by the Zappulla viaduct (Sicily, Italy) built in the first 1970s, accounts for both serviceability and ultimate loading conditions, thus representing a reliable tool for the quality control of existing bridge structures.