Banca de DEFESA: LUCAS SANTOS SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCAS SANTOS SILVA
DATE: 19/06/2023
TIME: 13:00
LOCAL: online
TITLE:

Desenvolvimento de materiais eco amigáveis de construção civil à base de Geopolímeros: Comportamento do material após exposição à altas temperaturas

KEY WORDS:

Geopolymers. Mechanical strength. High temperatures.

PAGES: 84
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

Geopolymers are a type of cementitious material produced from aluminosilicate materials, such
as fly ash, metakaolin, clays, and slag. They have mechanical and chemical properties that differ
from those of Portland cement, and therefore their compressive strengths can also vary. Over
the past decade, there has been a significant increase in interest and research on geopolymers
as a sustainable alternative to conventional cementitious materials such as Portland cement.
Understanding their structure and other mechanisms involved can contribute to the reduction
of the environmental impact of the construction industry, which is one of the main sources of
greenhouse gas emissions. The main objective of the study, which was divided into two phases,
is to determine the mechanical properties of these materials produced from metakaolin, sodium
hydroxide (NaOH) solution, at different concentrations (8 mol/L and 12 mol/L), and sodium
silicate, being subjected to exposure to high temperatures (300oC, 500oC, and 700oC). The
geopolymeric samples were cured at 60°C in an oven for 24 hours and remained at room
temperature for 28 days, being analyzed at ages of 1, 14, and 28 days of manufacture (pre- and
post-exposure). The obtained materials were subjected to mechanical strength tests and electron
microscopy. Physical properties such as water absorption, apparent porosity, apparent and
volumetric density were evaluated. In addition, the research found that the resulting
characteristic of each property depends on several factors, such as chemical composition, curing
time, humidity, temperature, manufacturing method. In reference to the second phase of interest
in analysis, characterized in the evaluation of mechanical behavior when the samples were
subjected to exposure to high temperatures, the results already expected regarding the negative
influence on uniaxial compressive strength were confirmed, that is, leading to a loss of
mechanical strength of the material due to several factors, mainly this exposure and the
temperature increments performed on it. It should be noted that all results discussed in this
study, for both phases, should not be generalized.

BANKING MEMBERS:
Externo à Instituição - JOAO PEDRO MONTEIRO CHELONI
Presidente - 1507262 - KURT STRECKER
Interno - 1527524 - WAGNER SOUZA MACHADO