Durabilità delle costruzioni in calcestruzzo armato, Restauro convenzionale

When degradation of concrete or corrosion of the steel reinforcement determine safety and serviceability conditions that are no longer acceptable, an intervention of restoration becomes necessary. Such as for design of the durability of the new reinforced concrete structures, even for the project of restoration works it is necessary initially to define clear objectives. A remaining service life should be identified, within which the restored structure will not have to reach a limit state which causes a loss of functionality of the structure (for example, corresponding to cracking, detachment or delamination of the concrete cover and/or an unacceptable loss of the cross section of the reinforcing bars). This paper deals with the approaches for the restoration of reinforced concrete structures, with particular reference to corrosion. The most common repair method is the conventional technique, based on the replacement of concrete which is no longer protective with a cement mortar. This paper describes the phases of the restoration and the requirements for the repair materials to be used.