3 research outputs found
Influence of recycled sand containing fillers on the rheological and mechanical properties of masonry mortars
No full textInternational audienceIn this work, we aim to study experimentally the influence of the fillers (<125 µm) of recycled sand on the properties of masonry mortars, with the same consistency, from the observation of the rheological behavior, slump, plasticity and shear strength and comparison of mechanical strength, compressive, flexural and tensile by splitting at 7 and 28 days. The formulation of the reference mortar based on natural river sand is made withcement CEM I 52.5 (C=506 kg/m3 ), with ratios water/cement = 0.5 and sand/cement = 3.0. The other recycled mortars were shown to have the same plasticity as the reference mortar, and the amount of water added was determined using the weight of the recycled sand. The study was carried out on four series of mortars based on recycled sand with and without superplasticizer, replacing natural sand with recycled sand with and without fillers with different percentages of 0, 15, 30, 40, 50, 75 and 100%. The obtained results show that the recycled sand has relatively low physicochemical properties compared to natural sand due to the heterogeneity and the large percentage of the old hardened mortar contained in the recycled sand, in particular the fractions below 250 µm, a high percentage of fillers greater than 10% and a very high water absorption, seven times higher. The comparative study of different mortar compositions with different percentages of recycled sand with and without fillers showed that fillers require more water, which negatively affects the physical and rheological behavior, but in most cases,the the mechanical performance isbetter than that of the control mortar, in particular the mortars with admixtures
