Characterization and selection of restoration mortars applied to the Eocene sandstones of Gipuzkoa used for building construction

We have studied the response of three commercial mortars (A, B and C) and a fourth one (synthesized by Teusa) under different laboratory tests (stiffness, setting time, water absorption, water suction, water-vapor permeability, porosity, density, pore-size distribution, salt crystallization, freeze-thaw cycling, flexural and compressive strength, and adhesion of mortars). The mortar A is an amorphous arid-free alite-mortar, whereas the B and, C are composed by quartz, alite and calcite. The comparison between the results of this paper and those obtained from the same tests carried out upon several samples of the Igueldo Sandstone (Eocene of Gipuzkoa, Spain) used in building construction have allowed to us to made a first approximation to the suitability of the different commercial products with respect to concrete lithologies. The A and C mortars are the best products to rejoin the Igueldo sandstone masonry-stones. The C and Teusa mortars would be satisfactory for whitewashing, but only with the addition of high-Ca lime or puzzolane. Finally, the A, B and Teusa mortars are thought to have a good behaviour for the replacement of the Igueldo sandstone masonry-stone