Banca de DEFESA: WESLEY FÊU DOS SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : WESLEY FÊU DOS SANTOS
DATA : 09/09/2016
HORA: 10:00
LOCAL: AUDITÓRIO DO CT
TÍTULO:

TREATMENT OF INFLUENCE ON THERMAL PROPERTIES MECHANICAL AND CONCRETE MICROSTRUCTURE self-compacting CONTAINING ADDITION OF metakaolin and filer LIMESTONE.


PALAVRAS-CHAVES:

mineral additions, self-compacting concrete and thermal curing.


PÁGINAS: 60115
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
SUBÁREA: Estruturas
ESPECIALIDADE: Estruturas de Concreto
RESUMO:

The manufacture of Portland cement is an activity that causes great environmental impact due to its high CO2 emission rate in the atmosphere. In order to reduce this impact, technical feasibility of alternative materials to replace Portland cement has been increasingly analyzed. It is already known the benefits that mineral additions infers to conventional concrete (CV), however, little is known of their use in self-compacting concrete (SCC) subjected to heat treatment. This work evaluates the effects of the incorporation of limestone fillers (LP) and metakaolin (MK) in the hydration of self-compacting concrete, when subjected to thermal curing. For this purpose six SCC compositions were produced, as a reference without mineral addition, four binary mixtures with replacement of cement with 10% MK, 10% LP, 20% MK and 20% LP and a tertiary with substitution of cement by 10% MK and 10% LP. The concrete were measured and made the tests slump flow, T500, L-box, Vtest and J-ring to characterize the SCC fresh. After started the crystallization reactions (about 3 hours), range called pre-curing, the molded specimens were cured through total immersion in a warm bath. The heating rate used was 20 °C/hr, reaching the maximum temperatures 50, 60 and 70 °C, with subsequent cooling 10 °C/hr. The total cycle time (pre-curing, heating, cooling and isothermal level) was 18 to 20 hours. Also, specimens were prepared which were cured by immersion in water at room temperature. The analyzed properties in the hardened state of all compositions were compressive strength at ages of 1, 3, 7 and 28 days at modulus, water absorption by capillarity, density, and total absorption to 28 days of age. The analysis of the microstructure of different concrete was given by scanning electron microscopy and X-ray diffraction at 1 and 28 days of age. The CAA thermally cured obtained a high increase in compressive strength at 1 day old, when compared to CAA cured at room temperature. For each dosage analyzed, there is a maximum temperature within the thermal cycle, which provides better mechanical performance to the CAA. The thermal curing causes changes in the microstructure, including, promote the rapid formation of calcium silicate hydrate (CSH).


MEMBROS DA BANCA:
Presidente - 1507841 - MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
Interno - 022.937.264-36 - ANDREZA KELLY COSTA NOBREGA - UFERSA
Interno - 022.621.844-96 - MARCOS ALYSSANDRO SOARES DOS ANJOS - IFRN
Externo à Instituição - GIVANILDO ALVES DE AZEREDO - UFPB
Notícia cadastrada em: 08/09/2016 16:21
SIGAA | Superintendência de Informática - (84) 3215-3148 | Copyright © 2006-2019 - UFRN - sigaa03-producao.info.ufrn.br.sigaa03-producao