Estudo da influência da substituição parcial da areia natural pelo resíduo proveniente do corte de pedras ornamentais nas propriedades de argamassas para impressão 3D

Abstract

The substitution of natural raw materials for waste, especially in the construction industry, has been quite widespread, this is due to the reduction of the negative environmental impact caused by the extraction of this raw material, as well as the cost reduction with the proper destination of these materials. waste. Likewise, the number of researches that study new construction methods has grown, such as 3D printing, an alternative for the production of materials in an intelligent way, with less cost and waste, in addition to less production time. Thus, this work aimed to evaluate the influence of partial replacement of the fine aggregate used by the ornamental stone cutting waste (RPPO) on the properties of mortars for 3D printing. The replacement of the fine aggregate by the RPPO was made in the proportions of 5%, 10% and 15%. To determine the properties of the fresh and hardened state of the mortars, tests of consistency index, infinite block, squeeze-flow, water absorption, specific mass, void ratio, compressive strength and flexural tensile strength were carried out. In addition, the physical and chemical characterization of RPPO was carried out through granulometry, X-ray diffractometry (XRD) and X-ray fluorescence (FRX) assays. The results indicate that the incorporation of RPPO increased the mechanical strength, however, it also increased the absorption and the void index. These last two increased due to the majority presence of calcite in the residue, which causes internal voids in the mortar due to its high porosity. The density of the mortar in the hardened state also decreased with the presence of RPPO, and this was due to the increase in the number of voids inside the mortar. Therefore, the partial replacement of natural sand by RPPO provided greater mechanical strength to the mortar, but also caused an increase in absorption and void content. Despite the increase in the void ratio and absorption, in the tests performed, there was no decrease in mechanical strength.