The influence of fine aggregates on Portland cement mortar compressive strength

Abstract The studies regarding the influence of stone-extracted materials on the mechanical properties of Portland cement mortars, has a growing interest in Mexico due to its geological diversity. This is of great relevance since, according to the mechanical properties, a suitable use of mortars can be proposed to satisfy specific requirements of regional construction systems. For this reason, the main goal of this research is to relate the composition of three types of aggregates commonly used in construction practices in two geologically different regions in Mexico with the mortar's compressive strength. Composition is analyzed by mineral crystalline phase identification. The analytical techniques employed were: Petrography, Qualitative X-ray Powder Diffraction, Scanning Electron Microscopy Energy-dispersive X-ray spectroscopy (EDS). The results obtained showed that sands with same origin sands (igneous sands) can provide very different compressive strength values; while aggregates from different origin (igneous and sedimentary) can have similar behavior regarding compressive strength. The amorphous fraction of the pink sand aggregate was attributed as the main factor regarding the change in mechanical properties. The gray igneous sand is adequate for a type N mortar, while the pink igneous sand and the rock limestone powder provide type M mortars.