Thin sections and polished sections of the mortars were prepared in an impregnation unit under vacuum with an epoxy resin. These were polished with 15 μm Al2O3 abrasive and the final lapping was performed with diamond pastes (15–1 μm). Thin-sections were analysed by light polarized microscopy using a petrographic polarizing Olympus BH2 microscope equipped with an Olympus DP-10 digital camera. Scanning electron microscopy observations were performed with a JEOL JSM-7000F Schottky-type field emission scanning electron microscope operating with an Oxford Pentafet photon energy instruments Link Isis X-ray (EDX) microanalysis system. Samples were carbon-coated to eliminate charging effects
