Banca de DEFESA: WALTER CONTABILE DE AMORIM MARTINS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : WALTER CONTABILE DE AMORIM MARTINS
DATA : 04/05/2022
HORA: 09:00
LOCAL: https://conferenciaweb.rnp.br/webconf/humberto-3
TÍTULO:

EFFECTS OF THE ADDITION OF REDISPERSIBLE COPOLYMER VAE ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF A GEOPOLIMERIC MORTAR FOR SETTING CERAMIC TILES

PÁGINAS: 95
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

The constant population growth and consequent housing growth demand new and more efficient construction systems, which drives the development of new, more environmentally friendly technologies. Brazil plays a leading role in the production and consumption of ceramic tiles, and adhesive mortar is used for their laying, which traditionally consists of sand and cement and, therefore, has a hard and brittle characteristic. In addition, the increasing use of more technological ceramic tiles and different substrates, with lower porosity and lower water absorption, makes the laying of the tile more difficult. Pathological problems such as detachment of ceramic tiles are common. In order to develop an environmentally friendly material that replaces the Portland cement, this work intended to develop a mortar with geopolymer binder for laying ceramic tiles. As the main characteristic of an adhesive mortar is adhesion, the modification of the geopolymer mortar with a redispersible vinyl acetate-ethylene (VAE) copolymer was intended to improve its mechanical and structural characteristics, contributing mainly to adhesion and flexibility issues. The obtained results showed that it is possible to make a material similar to an adhesive mortar, with geopolymer binder replacing Portland cement, using NaOH, metakaolin, and rice husk ash (molar ratios SiO₂/Al₂O₃ = 3.96, Na₂O/SiO₂ = 0.22, Na₂O/Al₂O₃ = 0.88), as an alternative to conventional mortar. The geopolymer mortar without additives presented, in relation to conventional cementitious mortars, at 28 days of age, superior results in terms of flexural tensile strength (9.25 MPa), compressive strength (56.6 MPa), and tensile bond strength after curing in oven (2.10 MPa), submerged in water (1.47 MPa), and open time (1.67 MPa). The addition of 2% to 10% VAE admixture was efficient in conferring transverse deformation to the geopolymer mortar, doubling the deformation (1.78 mm) with the addition of 6% of VAE. Addition of polymer admixture also helped to improve the consistency, in the fresh state, making the geopolymer slip resistant. It was also evidenced that the polymeric film, characteristic of polymeric admixtures in conventional mortars, performed chemical anchoring with the tile coating. Finally, it was observed that the polymer admixture also incorporate air into the mixture. It was found that the addition of the VAE copolymer, commonly used in cementitious materials, performed in a similar way in the geopolymer mortar. 

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1671394 - HUMBERTO NAOYUKI YOSHIMURA
Membro Titular - Examinador(a) Externo à Instituição - OTTO JACOMETO - USP
Membro Titular - Examinador(a) Externo à Instituição - ANTONIO EDUARDO MARTINELLI - UFRN
Membro Suplente - Examinador(a) Interno ao Programa - 1997753 - LUIZ FERNANDO GRESPAN SETZ
Membro Suplente - Examinador(a) Externo à Instituição - ANA PAULA KIRCHHEIM - UFRGS