Banca de DEFESA: Himad Ahmed Alcamand

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : Himad Ahmed Alcamand
DATA : 12/06/2017
HORA: 14:00
LOCAL: Centro Federal de Educação Tecnológica de Minas Gerais
TÍTULO:

DESENVOLVIMENTO E CARACTERIZAÇÃO FÍSICA, QUÍMICA E MECÂNICA DE COMPÓSITOS ÁLCALI-ATIVADOS TÊXTEIS REFORÇADOS COM FIBRAS DE JUTA

PALAVRAS-CHAVES:

Alkali-activated materials. Composites. Natural fibers.

PÁGINAS: 108
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
RESUMO:

The investigation of natural fibers as reinforcement in cement-based composites has grown recently, as a mean to improve their post-cracking mechanical behavior. The studies of natural fibers in alkali-activated materials (AAM), however, is still scarce. The objective of this work is to develop and assess the mechanical and physical properties of alkali-activated textile composites reinforced with jute fibers. A reference matrix is composed of alkali-activated metakaolin (MK), but this matrix was altered by partially replacing MK with silica fume (SF) and by blast furnace slag (BFS) in order to alter its composition (SiO2 / Al2O3 ratio = 3.0 and 3.9), and consequently the mechanical properties and durability. Surface treatment of the jute fibers was carried out with a carboxylated styrene butadiene polymer (SBR), in order to protect the fiber from the alkaline medium. For plain matrices, the evaluated properties were compressive strength, capillary coefficient, oxygen permeability and density. Those unreinforced matrices were also subjected to magnesium sulfate attack (30, 90 and 180 days of attack) to assess their durability. Jute-reinforced composites were subjected to bending tests before and after accelerated wetting and drying cycles. The results show that matrices containing SF and BFS are more susceptible to sulphate attack. In contrary, changes in the composition of the matrix and the introduction of jute fibers significantly improved the mechanical behavior of the composites, with best performance observed for the composites with higher SiO2 / Al2O3 ratio (3.9), higher BFS content (40%), where fibers are not surface treated with the SBR polymer.

MEMBROS DA BANCA:
Externo ao Programa - AUGUSTO CESAR DA SILVA BEZERRA
Externo à Instituição - EDUARDO HENRIQUE MARTINS NUNES - UFMG
Externo à Instituição - FLAVIO DE ANDRADE SILVA - PUC - RJ
Presidente - PAULO HENRIQUE RIBEIRO BORGES