Study of remaining fatigue life of Brazilian concrete bridges

Brazilian roadway bridges had their dynamics effects measured under a structural identification program. Data collected from the tests show that dynamic effects due to traffic can be higher than that produced by a 450 kN lorry, specified in the Standard for design of concrete bridges in Brazil. This fact can affect the fatigue performance of bridge structures in face of 100 years-life required on most current codes. So in this paper a parametric study on the fatigue life time of short-span reinforced concrete roadway bridges is performed. For this study a simulation model has been developed, which includes the most significant sources of uncertainty in the definition of traffic action on bridges as well as of structural response. The randomness in the results of the fatigue tests has been included through a statistical definition of the SN curves for the steel components of reinforced concrete bridges. As a final result, reliability indexes to fatigue are calculated and compared with target values as specified by codes.