Avaliação das propriedades no estado endurecido de argamassas com a utilização de resíduos da queima de biomassa da indústria cerâmica

Abstract

In the search for innovations in materials for civil construction, aligned with the concern for sustainability, the biomass used as an energy source generates some byproducts, one of which is ash. In the civil construction scenario, these ashes present a significant perspective for new technologies through reuse, aiming at the manufacture of construction components. In this context, the objective of this study was to evaluate the physical and mechanical properties of traditional mortars in the hardened state, replacing the traditional mortar mixture with ash from the burning of prunings of reforestation trees, the Eucalyptus. To conduct the study, the Protimiza Experimental Design software was used, adhering to the Face Centered Design (FDC) model to analyze two variables: the percentage of ash partially replacing the mixture and the time required for wet curing. The components for the production of the mortar were subjected to physical and chemical characterization, including the ash. The experimental model determined the quantity of prismatic mortar specimens, with dimensions of 4 cm x 4 cm x 16 cm, based on the proportions of 5%, 10% and 15% of ash in the conventional mortar mixture with a curing time between 7, 14 and 21 days. The results indicated that this partial replacement is a sustainable and technically viable option since the behavior of both variables was satisfactory. The tests showed that the replacement of 5% of ash in the mortar presented the best resistance results: 2.90 MPa in tension after 14 days and 10.14 MPa in compression after 21 days. With 15% of ash, the values dropped to 1.10 MPa and 4.21 MPa, respectively. Water absorption was lower with 5% ash (2.24 g/cm²), while 15% increased porosity, raising the absorption coefficient to 34.80 g/dm².min¹/². Statistical analysis, using graphs and response surfaces, evaluated variations and influences of the factors. Using ash instead of part of the mortar mix was a sustainable way to take advantage of this waste and use resources more efficiently.