Banca de QUALIFICAÇÃO: MARCELO TAVARES GOMES DE SOUZA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARCELO TAVARES GOMES DE SOUZA
DATE: 01/02/2024
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

MECHANICAL AND MICROSTRUCTURAL STUDY OF METACAOLIN GEOPOLYMERS WITH INCORPORATION OF ALFA GYPSUM WASTE

KEY WORDS:

Geopolymer; Metakaolin; Waste; Geopolymerization.

PAGES: 75
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

The high global demand for Portland cement has significant environmental impacts, accounting for approximately 8% of global CO2 emissions. To address this issue, The high global demand for Portland cement has serious environmental impacts, accounting for approximately 8% of global CO2 emissions. To mitigate this, alternatives such as mineral additions and new, more eco-friendly binders have emerged, consuming less energy and emitting fewer greenhouse gases. In this context, geopolymers stand out as a sustainable option for the construction industry. The use of metakaolin as a reactive precursor is particularly attractive due to its stable composition and greater availability compared to other precursors. Geopolymers also provide an interesting solution for the disposal of industrial waste, such as gypsum residue (RG), which is rich in calcium ions and can participate in geopolymerization reactions, improving mechanical properties. The aim of this study is to produce geopolymers with the addition of 5% industrial waste from gypsum molds used in the manufacture of sanitary ware. This waste consists of alpha-form calcium sulfate, which differs crystallographically and mechanically from the common gypsum used in construction. Geopolymers with RG incorporation were prepared, and the effects of the SiO2/Al2O3 molar ratio (2.5, 3.0, and 3.5) and curing temperature were evaluated. The tests conducted included compressive strength tests, FTIR, and XRD analyses. It was observed that geopolymers could not be produced with a SiO2/Al2O3 molar ratio of 2.5, likely due to the silicate source used. However, geopolymers with SiO2/Al2O3 ratios of 3.0 and 3.5 demonstrated satisfactory mechanical performance, with an increase of up to 223% in compressive strength with the incorporation of 5% RG and heat curing. FTIR analyses confirmed the occurrence of geopolymerization reactions. Based on the XRD results, it is concluded that RG contributed to the formation of portlandite, which likely was the mechanism responsible for the gain in mechanical performance in the material. Therefore, the results obtained so far indicate that the incorporation of RG was beneficial for the production of geopolymers. 

COMMITTEE MEMBERS:
Externo à Instituição - FÁBIO JOSÉ CARVALHO FRANÇA - IFPE
Externo à Instituição - DINIZ RAMOS DE LIMA JUNIOR - IFPE
Externo à Instituição - RICARDO HENRIQUE DE LIRA SILVA - IFPE