CRITICAL REVIEW OF MODELS FOR THE ASSESSMENT OF THE DEGRADATION OF REINFORCED CONCRETE STRUCTURES EXPOSED TO CORROSION

Exposure to aggressive environments is one of the main causes of reinforced concrete (RC) civil infrastructure degradation and damage, which can become critical if such structures are unprotected, as in the case of bridges, and even more crucial if subjected to seismic loading. This paper aims at analysing the models and approaches currently used for the assessment of RC structures exposed to different levels of corrosion. Furthermore, a specific section will be devoted to the evaluation of ageing on the seismic performance of bridges. A few numerical and analytical models of aged reinforced concrete structures have been chosen among thousands the proposed in the literature based on chronological time criteria. The methodological approach consists in comparing the results provided in the literature, based on experimental tests, with the outputs of Finite Element. These analyses were conducted by changing the mechanical properties of both concrete and steel rebars at different corrosion rates, which affect concrete strength, yielding stress, ultimate stress and stiffness of embedded steel rebars, and thus, bearing-capacity and seismic performance. New relationships for concrete strength and steel properties according to the level of corrosion are given. The results confirm the pivotal role and evolutionary nature of the impact of corrosion on the lifecycle of concrete structure