Durability of the earth mortar: Physico-chemical and mineralogical characterization for the reduction of the capillary rise

Abstract

Abstract. The stabilization of the earth material in the fields related to the earthen construction, in compliance with the standards in force, allows strong results of strength and durability. The chemical and mineralogical elements play an important role, in the presence of an 'optimum' cement dosage, to strengthen the ties between the clays and the grains of the earth.. This approach targets the search for better performances in the use of natural materials resource in an ecoresponsible habitat. This study presents the experimental results of the four techniques of mineralogical and chemical analysis on mortar specimens obtained from earth of the city of Fez. The results of the uni-axial compressive tests of the cylindrical specimens for this earth, associated by various percentages 0%, 4%, 7% and 10% by weight of cement, make it possible to analyze the effect of the mineralogical and chemical elements on the mechanical properties, namely Young's modulus, compressive strength and limiting deformation. However, we determine the water absorption coefficient of the mortar for different cement dosages in order to optimize the durability of the mortar against bad weather, rain and / or very wet climates. In the earth mortar of Fez, the strong presence of calcite (CaCO3), quartz SiO2 and dolomite CaMg (CO3)2 amplifies the improvement of the behavior of the material by the addition of cement. In fact, this strong presence of calcite stabilized the clay by cementing quartz and the cement matrix to strengthen the ties between the grains of the earth. In addition, with respect to the capillary rise, the water absorption decreases with the addition of cement. We also note that the evolution of the mechanical properties is of no importance except in the interval [4 to 7%] which represents the zone of effect for cement stabilization and which houses the optimum technicoeconomic cement dosing.Résumé. La stabilisation du matériau terre crue dans les domaines liés à la construction en terre, dans le respect des normes en vigueur, permet des résultats de résistance mécanique et de durabilité forts probants. Les éléments chimiques et minéralogiques y jouent un rôle déterminant et permettent, en présence d'un dosage 'optimal' du ciment, de renforcer les liens entre les argiles et les grains de la terre. Ainsi, la connaissance de la nature de la terre crue à utiliser dans la construction, par l'identification scientifique de ses composantes, est incontournable à cet effet. Cette démarche cible la recherche de performances meilleures dans l'utilisation des matériaux naturels et bio ressourcés au niveau d'un habitat éco responsable. Notre recherche présente les résultats expérimentaux des quatre techniques des analyses minéralogiques et chimiques sur des éprouvettes de mortier obtenues à partir d'une terre de la ville de Fès par la diffraction des rayons X, l'Infrarouge, le Microscope électronique à balayage et la fluorescence X. Les résultats des essais de compression uni-axiale des éprouvettes cylindriques de cette terre associé...

Development of Cement Stabilised Compressed Blocks Using Coal Bottom Ash: Influence of the Grain Size on Mechanical and Physical Properties of Blocks

“…Nevertheless, a slight increase in flexural strength was observed when the granular class of particles was reduced from 0/5 mm to 0/0.160 mm (or even 0/2.50 mm). It is worth noting that these values remain well above the values of flexural strength (ranging from 0.26 to 0.94 MPa) reported by Toguyeni et al (2018)[28].…”

“…However, the different amount of Portland cement used in the current investigation might explain the higher strengths obtained. The compressive strengths of the blocks in this study are slightly lower than those of other formulations of bricks with laterite produced with 3 or 6 press strokes and stabilized with 7% lime and 1.4% fibers (ranging from 6.05 to 7.19 MPa) [28], suggesting that comparisons among different formulations should be approached with caution. The results are also broadly consistent with the work discussed by Ammari et al…”

“…(2018) [28]. However, the different amount of Portland cement used in the current investigation might explain the higher strengths obtained.…”