Petrographic and petrophysical characterization of the main aerial and hydraulic mortars used in the construction and rehabilitation sectors

Petrographic and petrophysical characterization of aerial and hydraulic mortars allows their differentiation and the establishment of their most suitable applications. Natural, aerial or hydraulic lime mortars as well as artificial cements mortars present different physical properties. It shall be noted that physical characteristics, which depend on petrographic characteristics, impact on its mechanical properties. Therefore, this comparative study with standardised techniques and tests, has analysed these mortars from a petrographic, petrophysical and mechanical point of view. The chemical processes and porosity originated during mortar production and subsequent curing phase explain mortar physical behaviour (hardness, strength, as well as fluid access and retention). This study confirms that air lime mortars are the most porous and least resistant while cement mortars are the most resistant and impermeable. Finally, natural hydraulic lime mortars, with petrographic characteristics similar to cement mortars, have physical-mechanical properties close to aerial ones, although they are more impermeable and resistant.