Banca de QUALIFICAÇÃO: THIAGO MARQUES VIANA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : THIAGO MARQUES VIANA
DATE: 25/04/2024
TIME: 09:00
LOCAL: https://conferenciaweb.rnp.br/sala/peter-ludvig
TITLE:

Evaluation of de behavior of UHPCs with multiwalled carbon nanotubes addition and polypropylene fibers at elevated temperatures

KEY WORDS:

Ultra-high performance concretes, Reactive powder concretes, Spalling, Carbon nanotubes, Polypropylene fibers, Performance at elevated temperatures.

PAGES: 66
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

Recent research has become interested in ultra-high performance concretes (UHPC), which are cementitious composites with improved properties in relation to the usual high-performance concretes. Reactive powder concrete (RPC) constitutes the main type of UHPC and consists of a material in which there are no coarse aggregates, in addition to various powders being present, which gives the material its name. Even though they are composites with superior properties, UHPC still need more studies so that their performance can be improved and their use can be reliable and widespread. The use of nanomaterials to improve UHPC, including carbon nanotubes (CNT), has been gaining attention, as this nanomaterial has excellent mechanical properties and its presence in the composite can promote significant improvements in mechanical resistance, modify thermal properties and even improve its performance at elevated temperatures. This is important since UHPC, as they are very dense matrix materials, tend to have inadequate performance in this case, including explosive spalling being detected due to the water vapor pressure and thermal stresses that forms during heating, a phenomenon known as spalling. Previous research has detected that the presence of CNT alters the performance of the material, potentially mitigating or even preventing the occurrence of the phenomenon, which is of great relevance for studies involving UHPC. This finding is important because UHPC need to improve performance at elevated temperatures for greater safety in their use, given situations to which buildings and structures are exposed, such as in a fire. Therefore, this research project for qualification proposes the evaluation of the performance of the incorporation of CNT in UHPC in relation to heating, in a comparative way with the use of a strategy whose data is already more consolidated in the literature, the application of polypropylene fibers (PPF). Furthermore, the aim is to deepen knowledge and better investigate the prevention mechanism created by the presence of CNT, still unknown in the literature. In this context, several properties and aspects will be investigated and fed into the creation of a predictive regression model on spalling.

COMMITTEE MEMBERS:
Presidente - PETER LUDVIG
Interna - JUNIA NUNES DE PAULA
Interno - AUGUSTO CESAR DA SILVA BEZERRA
Externo à Instituição - ESEQUIEL FERNANDES TEIXEIRA MESQUITA - UFC