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2021

Selle valdkonna püsiv URIhttp://hdl.handle.net/10492/6821

Sirvi

Sirvi 2021 Märksõna "agro-industrial wastes" järgi

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  • Pisipilt
    Kirje
    Application of pineapple fiber in the development of sustainable mortars
    (Estonian University of Life Sciences, 2021) De Azevedo, A.R.G.; Rocha, H.A.; Marvila, M.T.; Cecchin, D.; Xavier, G.C.; Da Silva, R.C.; Ferraz, P.F.P.; Conti, L.; Rossi, G.
    Due to the great worldwide increase in pineapple production, countries like Brazil and India have problems regarding the correct disposal of residues from the production of this fruit. One of the possibilities is the reuse of these residues in the form of fibers in cementitious materials, as is the case with mortars. As a result, the objective of this work is to evaluate the application of pineapple fibers in mortars in the proportion of 1: 4 (cement: sand) with addition of fiber treated in NaOH in the proportion of 3 and 6%. The properties of mechanical resistance, water absorption, mass density and adhesion were evaluated, aiming to apply the mortar in coatings of rural environments. The results indicate that the fibers reduced the mortar density and increased the mechanical strength. However, there was a reduction in adherence, especially with the use of 6% fiber, in addition to an increase in water absorption. Based on the results, it is concluded that it is feasible to use 3% of pineapple fiber for the production of coating mortars in rural environments because the results obtained in the investigation are compatible with this application and with the established normative limits.
  • Pisipilt
    Kirje
    Influence of different methods of treating natural açai fibre for mortar in rural construction
    (2021) Rocha, D.L.; Azevedo, A.R.G.; Marvila, M.T.; Cecchin, D.; Alexandre, J.; Carmo, D.F.; Ferraz, P.F.P.; Conti, L.; Rossi, G.
    Açai is a typical Amazonian fruit that has enormous potential for use in medicines and foods, whose consumption has been growing year after year. One of the major environmental impacts related to Açai is the generation of agro-industrial wastes, which are disposed of in landfills. One of the major problems related to the reuse of natural fibres in cementitious materials is related to their durability due to the alkalinity of the matrix. Thus, the objective of this work was to evaluate three different methodologies for surface treatment of Açai fibre, by immersion in NaOH, KOH and Ca(OH)2 solution to mortar application in rural construction. After the treatments, the fibres were added in a proportion of 2.5 and 5.0% in relation to the cement mass, in addition to the reference mortar (without fibre) in the making of the prismatic specimens (40×40×160 mm) and cured for 28 days in room temperature. Right after the curing period, the specimens were evaluated according to the mechanical strength of flexion and compression, workability, water absorption by capillarity and mass density in the hardened state of each methodology. The results showed that the best treatment methodology is with NaOH solution, with the addition of 5% Açai fibre in relation to the cement mass, producing a suitable mortar for use in rural buildings.