Banca de DEFESA: VICTOR PINHEIRO DA COSTA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : VICTOR PINHEIRO DA COSTA
DATA : 30/11/2017
HORA: 14:00
LOCAL: AUDITÓRIO DO CT
TÍTULO:

Characterization of sterile residue from granitic pegmatitic deposits granulometrically reduced for application to earthworks.


PALAVRAS-CHAVES:

Mining residue; paving; feldspar


PÁGINAS: 107
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
SUBÁREA: Geotécnica
RESUMO:

Mining activity as any process of extraction of natural resources
causes impacts to the environment, whether in regard to changes in
natural areas through their exploitation or in the generation of waste
arising mainly from their mining and processing. Assuming that mineral
resources are exhaustible and that the construction industry is
responsible for the consumption of up to 50% of all mineral resources
exploited on the planet, it is imperative to develop techniques for the
reuse of mining waste in construction for that the use of natural goods
and the accumulation of waste occur, thus minimizing the impacts
caused to the environment. In this work, a proposal is proposed for
adequate disposal of the residues from the pegmatitic feldspar of the
Parelhas / RN region by means of their inclusion in geotechnical
works. For this, the sterile pegmatitic feldspar (REFP) was subjected
to a granulometric treatment process, obtaining a material with 100%
passing through the sieve n ° 4 (4.8 mm). Subsequently, it was
submitted to physical, chemical, mineralogical and mechanical
characterization tests. Before the results were characterized as non-
plastic and well graded silt sand with a solids specific mass of 2.66 g /
cm3 and non-uniform granulometry. The results of X-ray diffraction
showed a high percentage of silica (64.13%) and aluminum (15.08%),
with a low content of total alkalis (10.62%) and a high oxide content of
iron (5.25%) in relation to the chemical requirements for its
consumption in the ceramic and glass industries. It was designated as
an A-2- 4 material by the TRB (Transportation Research Board), which

has excellent penetration support capability and can be used when
compressed under modified energy under optimal conditions (pdmáx e
wót), as a base element in pavements with N <5.106. However, a loss
of 50% of its penetration support capacity (ISC) was observed for
moisture content equal to wót ± 1, revealing the need for a rigorous
control when applied to pavements. As for the direct shear tests, the
non-flooded samples showed cohesion values and friction angle at
peak voltages ranging from 15 to 8 kPa and 53 to 43 degrees
respectively for the normal, intermediate and modified compaction
energies and overloads of up to 200 kPa. The flood did not cause
measurable changes in the values of the peak voltages, however, it
resulted in lower residual voltages. The REFP was presented as a
material of low compressibility, not demonstrating expandable or
collapsible behavior when flooded to the stress levels applied in this
research. The results shown by the variable load permeability tests for
samples molded under optimum conditions in the normal, intermediate
and modified compaction energies, demonstrate that the residue is
medium permeable (1,56 − 1,28 cm/s2). REFP presented 83% of
pozzolanic activity, a result that can be satisfactory in mortars,
concretes, soil-cement and improved soils. Technically, the residue
presented properties that satisfy its use in earthworks and / or mixtures
with binder elements, however, further studies are necessary to
evaluate the energy cost required for its granulometric processing and
the influence areas of its location to validate its applicability in these
segments.


MEMBROS DA BANCA:
Externo à Instituição - ALEXANDRE DA COSTA PEREIRA - IFRN
Presidente - 2085750 - FAGNER ALEXANDRE NUNES DE FRANCA
Interno - 1284389 - MARIA DEL PILAR DURANTE INGUNZA
Interno - 1692497 - OSVALDO DE FREITAS NETO
Notícia cadastrada em: 13/11/2017 12:49
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