Experimental characterisation of lime based rendering and repointing mortars. Sefinition of relevant laboratorial and in situ tests : Compatible materials and interventions for the conservation of historic masonries

It is necessary to define a methodology, as objective as possible, to support decisions about the need of repair of ancient masonry mortars and the suitability of repair and substitution materials. Tests and specifications related to those test results are the obvious answer. For ancient walls and for repaired walls (by consolidation techniques or by partial replacement of material), it is important to be able to perform in situ tests, if possible quick and not very intrusive ones. They must permit an assessment by comparison, even if they are not quantitative in an absolute way. However, there are no standardised in situ tests for old masonry mortars. In this paper a methodology is described to assist decisions about repair; a set of in situ tests not yet fully tried is presented in a preliminary way; specifications for its results are outlined; conclusions are drawn and future work is planned.