Patch Restoration Method: A new concept for concrete heritage

• Patch Restoration Method (PRM), a method to support restoration on concrete heritage.
• A non-contact and easy to implement restoration approach using image processing.
• PRM validation using mortar specimens subjected to accelerated aging tests.
• PRM covers the entire intervention process, from inspection to monitoring.

Concrete has been used to build some of the most outstanding constructions since the last Century. Some of these are definitely part of the World’s heritage. In order to preserve this legacy, interventions must be performed according to very strict restoration requirements. However, when referring to concrete, there is an almost generalised lack of concern in this subject.Thus, a method specifically designed for concrete heritage, called ‘Patch Restoration Method’ (PRM), was developed. PRM aims to encompass the whole process, from assessment to intervention, and have been developed to ensure the match between the repairing mortars and the concrete substrate, taking into account the effect of aging.After the proof of concept, PRM was applied in an exceptional example of concrete heritage: the headquarters of Fundação Calouste Gulbenkian, in Lisbon, Portugal. Results obtained are presented and discussed, and conclusions are drawn. Finally, the tentative guidelines for the PRM are proposed.