Use of natural pozzolans with lime for producing repair mortars

Natural pozzolans were used selectively in combination with lime for the production of mortars used in structures where water tightness was required such as aqueducts, baths, and pipes many centuries ago. Their use in building materials was diachronic. The appreciated properties of mortars containing pozzolans were the increased durability and strength and the dense structure in relation to pure lime mortars. In the present paper, two natural pozzolans from Greece were analyzed systematically in order to record their mineralogical, chemical, morphological and physical properties. These pozzolans were used for the production of repair mortar, and the mechanical and physical properties of the mortars were also recorded. From the results, it is derived that the pozzolans tested were materials of high quality and reactivity and could be used for the production of compatible repair mortars for the restoration of monuments and historic buildings. The elaboration of natural pozzolans by grinding could lead to further increase of their reactivity. From the analysis, valuable criteria could be instituted for the qualitative evaluation of natural pozzolans.