Experimental procedure for the pre-qualification of strengthening mortars

This study describes an innovative laboratory procedure used as a preliminary design stage for the pre-qualification of strengthening mortars applied to historic masonry buildings. An investigation of the long-term behavior of different strengthening mortars was carried out through static and fatigue tests on different dimensional masonry specimens, in order to formulate a judgment about their compatibility with the mechanical characteristics of historic masonry structures. This methodology has proved useful in avoiding the errors associated with materials that are not mechanically compatible and guarantees the durability of strengthening work. Special attention was devoted to fatigue and thermo-hygrometric aspects, which are often overlooked, but whose effects on the masonry system are significant enough to compromise the validity of repair work.