EVALUATION OF THE INCORPORATION OF PEANUT POD ASH IN GYPSUM MATRIX COMPOSITES

• DOI: https://doi.org/10.22533/at.ed.317532524023

• Palavras-chave: Construction. Materials with lower environmental impact. Physical-mechanical properties of composites.

• Keywords: Construction. Materials with lower environmental impact. Physical-mechanical properties of composites.

• Abstract:

  The aim of this research was to analyze the effects of incorporating peanut pod ash into gypsum matrix composites, with a view to disposing of waste for environmental preservation and also improving the properties of gypsum matrix composites. To this end, the pods were first reduced to particles in a knife mill and evaluated in terms of chemical composition using the total extractives, ash, lignin and holocellulose content tests, as well as physically using the bulk density test. After this procedure, the particles were subjected to heat treatment in a muffle furnace for a period of 3 hours at 300°C. The ash obtained from this process was incorporated into gypsum matrix composites with a constant water : gypsum ratio of 0.6 through different mass substitution levels (0%, 2.5%, 5.0%, 7.5% and 10%) of gypsum for the ash. The specimens measuring 10x10x10mm were then subjected to physical tests of humidity, water absorption at 2 and 24 hours, apparent density and the mechanical compression test. The results of these tests showed that the incorporation of waste ash did not have a significant impact on the moisture test; on the other hand, there was an increase in water absorption which can be explained by the large presence of holocellulose in the peanut particles (41.61%). With regard to apparent density, the composites showed a concomitant decrease with the incorporation of peanut pod ash, which can be explained by the low density of the residue (0.19g/cm³), resulting in lighter composites. With regard to mechanical properties, the sample with 2.5% ash had the highest compressive strength among the test specimens. It is therefore possible to conclude that the ash from the lignocellulosic waste studied proved to be viable for incorporation into gypsum matrices since the composites showed greater strength and lightness. Further studies are needed to confirm the trends analyzed and contribute to the possible dissemination of an innovative composite with a lower environmental impact.