Banca de DEFESA: BRUNA SILVA SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : BRUNA SILVA SANTOS
DATA : 03/04/2020
HORA: 14:00
LOCAL: PPEC
TÍTULO:

INFLUENCE OF GRANITIC ROCK FINE (FRG) ON ALLCALIS-SILIC REACTION (RAS) IN CEMENTITIOUS MATRICES

PALAVRAS-CHAVES:

Alkali-aggregate reaction. Granitic rock powder. Reactive aggregate. Osipov's theory. Pyrex glass.

PÁGINAS: 134
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
RESUMO:

According to the Brazilian Mining Institute, in 2017, Brazil produced around 420 million tons of aggregates for civil construction, a large part of them for crushing rocks. This rock comminution activity generates a fine residue that, when improperly disposed of, promotes a negative environmental impact. When its diameter is less than 75µm, this material is called crushing thickness and can be used in concrete and clays. According to a theory proposed by Russian researcher Albert Osipov, if thin materials receive a reactive added value higher than cementitious matrices, they can act as mitigators of the aggregated alkali reaction (RAA), accelerate or consume alkalis, with a mass still in a fresh state. However, the effectiveness of their action depends on their degree of reactivity (amorphism), fineness and added content. Based on this theory, fines of granitic rock (FRG) were studied. Two different deposits were included, incorporated into the concrete and mortar as an addition to the cement, in the contents of 10 and 20%, by mass, being used, still, or thin Pyrex glass (FP), these results were compared to those obtained by granites. In addition to the tests related to the verification of the mitigation proposed by the Brazilian standardization (NBR 15577-5), it was selected as an addition of the FRG that influences the physical-mechanical characteristics and the microstructure of the mortar. As a result, it was found that the FRG reduced the expansion of the pump without accelerated testing, with the fines of the largest specific surface area being the most efficient in this reduction. In addition, the introduction of FRG promotes a reduction in cement consumption, without prejudice to the physicalmechanical properties of mortars. 

MEMBROS DA BANCA:
Interno - 2137887 - CLEBER MARCOS RIBEIRO DIAS
Presidente - 1779028 - DANIEL VERAS RIBEIRO
Externo à Instituição - HELENA CARASEK CASCUDO - UFG