Banca de DEFESA: Lilian de Sousa Alves

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Lilian de Sousa Alves
DATE: 05/05/2023
TIME: 09:00
LOCAL: PLATAFORMA TEAMS
TITLE:

MICROSTRUCTURE STUDY AND CHARACTERIZATION OF CEMENT PASTE WITH ADDITION OF KRAFT FIBERS

KEY WORDS:

: Kraft fiber; Cement matrix; Composite; Microstructure.

PAGES: 169
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Construção Civil
SPECIALTY: Materiais e Componentes de Construção
SUMMARY:

Civil construction plays an important role in a country economic and social development, but it is also a major waste generator. Cement packaging is one of those wastes, which can be recycled and reused as a fiber in cementitious matrices. There are several studies on composites using vegetable fibers, however, the studies regarding the use of kraft fibers in Portland cement matrix are recent and do not address its behaviour in the alkaline environment. This work aims to study the chemical and microstructural characteristics of a composite, in order to comprehend the durability of kraft fibers when inserted in alkaline environments, such as Portland cement. Therefore, experimental tests were performed and divided into four stages: material composition; composite production; evaluation of fibers in different alkaline media and composite characterization. To produce the composites, Portland cement, kraft fibers and water were used. Analyses were performed with different kraft fibers addition ratios (reference, 0.5%, 1.0% and 3.0%) and water/cement ratios (0.40, 0.45 and 0.50). From the results, it can be seen that kraft fibers can be used in cementitious matrices, since they obtained a low inhibition index. Also, there was no delay in the hydration of Portland cement due to the inhibitory components present in the kraft fiber. Moreover, there was a reduction in the content of CH (calcium hydroxide) in the cement pastes, which is beneficial, because this is responsible for the mineralization of the kraft fibers. The mineralization is a phenomenon observed in the fiber immersed in calcium hydroxide solution, due to the high pH of the solution and migration of products to the fiber structure

BANKING MEMBERS:
Presidente - 2712272 - CLAUDIO HENRIQUE DE ALMEIDA FEITOSA PEREIRA
Interno - 1734221 - JOAO HENRIQUE DA SILVA REGO
Externa à Instituição - ANDRIELLI MORAIS DE OLIVEIRA - UFG
Externo à Instituição - ENIO JOSE PAZINI FIGUEIREDO - UFG
Externo à Instituição - Francisco Gabriel Santos Silva - UFBA