Seismic Response of Reinforced Concrete Structures Affected by Reinforcement Corrosion: Fid-Bau Portal

Seismic Response of Reinforced Concrete Structures Affected by Reinforcement Corrosion

Simioni, Paola

Durability of RC structures is a well known critical issue, since the deterioration of the materials may significantly compromise the structural performance. Experience shows that reinforcing steel corrosion is one of the major sources of degradation, increasing the structural vulnerability to extreme loads and natural hazards in terms of reduction of load bearing capacity and structural ductility, with noteworthy implications in seismic prone areas. To support decision makers with a better comprehension of the matter of safety assessment, the concept of risk management has recently become of great concern also in civil engineering, being already popular in other disciplines. A general approach has been developed within the IGC 802 to manage disaster risk and represents the backbone of this thesis, which is developed at two levels. At a ômicroö level a new bond law is proposed to describe the degradation of the bond-slip behaviour due to corrosion. At a ômacroö level the variation of the seismic response of a RC building affected by a carbonation attack respect to sound conditions is evaluated. In view of the high level of uncertainty involved, the research is carried out in a probabilistic context and, after performing sensitivity analyses, the structural risk is calculated as probability of occurrence of the hazards (earthquake and corrosion) times expected damage. The probability of corrosion initiation is derived from a detailed durability model, while the site-specific hazard maps are used to estimate the probability of an earthquake occurrence. Non linear static analyses are then performed to assess the expected damage in terms of reduction of structural ductility of the corroded building respect to the new one. Interestingly, if repeated at different time periods, the proposed methodology provides the risk trend over time for the considered construction, or alternatively it can be applied at a territory level to rank buildings in priority lists of intervention.