Banca de QUALIFICAÇÃO: JÔNATAS MACÊDO DE SOUZA
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.STUDENT : JÔNATAS MACÊDO DE SOUZA
DATE: 10/02/2023
TIME: 09:00
LOCAL: meet.google.com/tgn-kipx-zev
TITLE:
Incorporation of wood ash and metakaolin in the production of soil-cement lightweight bricks
KEY WORDS:
Wood ash, ecological brick, sustainability, reuse, new materials.
PAGES: 80
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Cerâmicos
SUMMARY:
Given the concern with the emission of greenhouse gases, companies in various economic sectors are using biomass as a fuel for thermal energy generation in boilers instead of the fossil fuels usually used. One of these biofuels is wood chips, a small lignocellulosic material obtained from wood chopping. However, despite the environmental advantage of offsetting carbon dioxide (CO2) emissions, when burned, the material generates ash as residue that, when not used in agriculture as fertilizer or for composting, is sent to landfills, causing environmental impacts. Thus, there is a need for further studies on the physical and chemical properties of the ash so that new applications are thought of to promote a better destination for the residue. In view of the above, this research aimed to investigate the influence of wood ash replacing clayey-silt soil (classified as A-6) in producing lightweight soil-cement bricks. In all, 7 formulations with 10% cement were produced, of which one was a reference (without substitutions), 3 with partial substitution of the soil by the contents of 5%, 10% and 20% of ash and 3 with the same contents of ash plus 5% of metakaolin in place of soil. The bricks were cured for 7 days in a humid chamber. Then they were submitted to compressive strength and water absorption tests at 7 and 28 days according to NBR 8492 and durability tests at 7 days according to NBR 13554. The samples that presented the best performance in the compressive strength test at 28 days, before and after the durability test, were submitted to microscopic characterization tests through X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. The tested bricks showed low specific weight, less than 1.65 g/cm³ at 28 days, especially for the sample with soil replacement by 20% ash and 5% metakaolin with 1.22 g/cm³. As for the compressive strength at 28 days, with the exception of the formulation with soil substitution by 20% of the residue, all others showed results higher than 2 MPa. Due to the high content of fines present in the soil (about 61.21% passing sieve No. 200), the average absorption of all compositions was above 20%. After being submitted to the durability test by immersion and drying, all formulations presented mass loss below the 7% indicated for soil type A-6. The microstructural characterization identified mineralogical phases of the cementitious reaction products as CSH and CASH, which were confirmed by the microstructure images obtained in SEM. The results are promising and validate the use of wood ash for the production of soil-cement lightweight bricks.
COMMITTEE MEMBERS:
Presidente - 1149564 - WILSON ACCHAR
Externo à Instituição - CLAWSIO ROGERIO CRUZ DE SOUSA - UFERSA
Externa à Instituição - SHEYLA KAROLINA JUSTINO MARQUES - IFAl
Externo à Instituição - VAMBERTO MONTEIRO DA SILVA - IFPB