MECHANICAL AND CHEMICAL CHARACTERISATION OF POZZOLAN OF MIDDELE ATLAS IN MOROCCO

This paper presents an experimental study in order to determine the mechanicals properties of the concrete and mortar with pozzolan material. Crushed pozzolan was used as lightweight aggregate and natural sand was used in all mixes to produce a lightweight aggregate concrete. These pozzolanic materials are abundant volcanic area but its use is very limited. The characterizations studies of this material can be useful to product lightweights aggregates concretes, thermal isolated material for energy efficiency in building, environment impact and Sustainable development issues. The properties of hardened and fresh concrete produced from the pozzolan including workability, density, compressive strength, flexural strengths resistance were tested. The chemical, mineralogical analysis, geophysical properties (appearance and shape, natural water content, porosity, density and water absorption) are studied. The properties of the concrete studied were also compared with those of the standard concrete. In order to obtain more knowledge on the mechanicals and chemicals properties of pozzolan concrete, six mixtures were tested: one specimen with Portland cement (control) and tree mixtures with, 25%, 40%, and 100% of pozzolan. Fresh concrete mixtures were tested for workability and density. While for the hardened concrete specimens, compressive strength and flexural strength were determined after 3, 7, 14 and 28 days. X-ray fluorescence, X-ray diffraction and the scanning electron microscope was used to determine the microstructure and to determine the chemical and mineralogical composition of the material. The results of this study show that the replacement of 30% river sand by sand of pozzolan, increase the strength of the mixtures.