POROSITY DETERMINATION IN STONY MATERIAL USING SCANNING ELECTRON MICROSCOPY AND IMAGE ANALYSIS

摘要

A stony material natural (stone) or artificial (mortar, concrete, brick, etc.) is composed of an attach mineral (arid), in a cement matrix. Among these constituents a series of empty spaces, pores and fissures appear whose distribution and volume condition its properties, changeability and durability. The pores are characterized by a series of properties that can be quantified: morphology (spherical pores, cylindrical, planar), characteristic dimensions (macrospores, microspores) and continuity (total, accessible, inaccessible porosity). Different samples of sedimentary stones have been studied, being presented the study of a sandstone and a conglomerate. The sandstone are stones originated by consolidated detritus, constituted by size grains between 0.07 and 2mm. During their deposition the sandstone porosity is high, but the processes of cementation reduce the porosity strongly increasing the cohesion of the stone. The conglomerate are constituted by fragments of superior size at 2mm that difficult the adherence between the arid and cement matrix providing a higher porosity.