Banca de DEFESA: KARLISSON ANDRE NUNES DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : KARLISSON ANDRE NUNES DA SILVA
DATE: 28/03/2024
TIME: 14:00
LOCAL: Universidade Federal de Alagoas
TITLE:

STUDY OF MECHANICAL AND ELECTROTHERMAL PROPERTIES OF STRATIFIED CONCRETE ELEMENTS WITH FUNCTIONAL CLASSIFICATION

KEY WORDS:

stratified concrete; functional grading, mechanical properties; electrothermal properties.

PAGES: 150
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Construção Civil
SPECIALTY: Materiais e Componentes de Construção
SUMMARY:

The search for concrete constructive elements with functional classification, capable of adequately responding to different actions and stresses, has been the subject of research aiming at functional grading, stratification, additive manufacturing, and 3D printing as pathways for concrete elements to behave effectively, without waste, with improved competitiveness, and greater efficiency. The technique of stratification, allocating concretes in layers, is the most accessible and has been applied by several authors to achieve concrete with better performance. This research aimed to study the mechanical and electrothermal properties of stratified concrete elements with functional classification (CECF), focusing on the behavior of beam and slab elements under pure bending, and walls under electrothermal actions and aggressive agents. For this purpose, concretes with normal density (CDN) and low density, foam cellular concrete (CCE), the latter in two foam dosages (10% and 20%) referred to as CCE10 and CCE20 respectively, were produced. These concretes served as references. CECF were produced in two layers (CCE1020 and CCE20CDN) and in three layers (CCE1020CDN), factors such as specific mass, concrete position in the mold, and time of deposition between layers were determined. All concretes were produced on two different days, on the first day called 1st molding, and on the second day called Replica. Each concrete was tested for compression, tension, modulus of elasticity, pure shear, electrical resistivity, thermal conductivity, and resistance to high temperature. The compressive strength of the concretes showed values greater than 20 MPa, classifying them as structural concretes. In the four-point bending test, stratification had positive effects, resulting in practically equal or higher results compared to reference concretes. In the modulus of elasticity test, there was a reduction in values compared to CDN values; however, there was a gain compared to individual concretes CCE10 and CCE20. In the pure shear test, all stratified concretes (CCE1020, CCE20CDN, and CCE1020CDN) presented practically the same value of pure shear stress, around 5.5 MPa. In the high-temperature compression resistance test, the behavior of the concretes subjected to 200ºC and 400ºC was quite similar. The stratified concrete CE1020 showed the least variation compared to the other concretes. The electrical resistivity of stratified concretes was higher than 20 KΩ.cm, making them negligible for reinforcement corrosion development. The heat flow of the concretes was also determined, with CCE1020 concretes showing the best performance, as they are composed of concretes with lower specific mass. Overall, stratified concretes showed better performance compared to reference concretes, proving that they can bring better benefits to concrete elements.

COMMITTEE MEMBERS:
Presidente - 2120767 - PAULO CESAR CORREIA GOMES
Interno(a) - 2544065 - MARCIO ANDRE ARAUJO CAVALCANTE
Externo(a) ao Programa - 1582140 - KAROLINE ALVES DE MELO MORAES - UFALExterno(a) ao Programa - 3182546 - CASSIA VANESSA ALBUQUERQUE DE MELO - UFALExterno(a) ao Programa - 1927109 - WELLINSILVIO COSTA DOS SANTOS - UFALExterno(a) à Instituição - CAMILA DE SOUSA VIEIRA
Externo(a) à Instituição - SHEYLA KAROLINA JUSTINO MARQUES