TESTING PROPERTIES GOVERNING THE DURABILITY OF LIME-BASED REPAIR MORTARS

Lime-based mortars seem to be preferred in repairing historical structures. The long-term performance of lime-based repair mortars is closely related to durability issues concerning the old structure substrate, the new repair mortars and the interface between the two aforementioned materials, which is also much influenced by the technique of mortars application. It is well known that durability is a multifunctional property affected by a number of parameters, including local environmental conditions. However, experience (based on research and survey of real case studies) showed that some of the parameters concerning the characteristics of materials play a dominant role in assessing the durability of repair lime-based mortars and have a direct impact on longevity of the repaired structure. This paper presents comments of review papers concerning research publications or case studies, as well as Master or PhD theses supervised or carried out by the members of RILEM TC 277 LHS. Through the review and evaluation of research and common practice concerning durability challenges, we anticipate to find answers to questions arising in assessing the durability of repair lime-based mortars, such as: the most often encountered failures due to mortar durability inadequacy, the mortar properties/characteristics that seem to be influential on durability, the test methods used for testing the durability of lime-based mortars and comments related to their applicability and performance and the importance of quality control and on site execution practices.