Characterization of repair mortars for the assessment of their compatibility in restoration projects: Research and practice

Repair mortars used for restoration are assumed to be highly compatible with historic materials in terms of physical, chemical and mechanical properties in order to assure the durability of masonry on the long term. Compatibility criteria are defined based on the original mortar characteristics but the quality and the performance of the repair mortar after application on masonry are not generally evaluated. From this perspective, historic mortars and repair mortars from three historic masonry structures were analyzed in terms of chemical, mineralogical, and physical point of view. A methodology is given taking into account the added value of analytical techniques and the basic requirements from both practical and scientific point of view.