Banca de QUALIFICAÇÃO: BRUNO ATHAÍDE BACELAR

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : BRUNO ATHAÍDE BACELAR
DATE: 21/08/2023
TIME: 10:00
LOCAL: https://teams.microsoft.com/l/channel/19%3aTGDrfmj8a-EiKvTySiJ4oOfRHpSEa7BN6iOpjkacXvs1%40thread.tac
TITLE:

Modeling of carbonation corrosion and determination of the service life of sustainable ultra-high performance concretes (UHPC)

KEY WORDS:

UHPC; carbonation; chloride ion penetration; sustainability; response surface methodology; optimization

PAGES: 63
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Construção Civil
SPECIALTY: Materiais e Componentes de Construção
SUMMARY:

Climate change has been a great concern for humanity and the construction industry is one of the main responsible for the environmental impacts on the planet, with Concrete and cement production being responsible for using high amounts of mineral resources and greenhouse gas emissions. A few alternatives are possible to produce more sustainable concrete structures, such as increasing the mechanical properties to obtain smaller cross sections or to produce more durable structures, with higher service lives. Ultra-High Performance Concretes (UHPCs) achieve excellent mechanical and durability properties through a low water/binder (w/b) ratio and a high cement content (~900 kg/m3). The high cement content increases the environmental impacts of UHPCs. However, the mechanical properties of UHPC make it possible to build lighter structures, with reduced material consumption, which leads to lower environmental impacts for their production than conventional concrete structures. The higher durability properties could further reduce the environmental impacts of UHPC structures. However, life cycle assessment (LCA) studies carried from cradle to gate only guess the service life of UHPC structures. It is known that UHPCs are more durable than conventional concretes, but not exactly how much durable and how different materials affect this durability. Thus, it is necessary to develop models for the durability of UHPCs. This research project aims to produce more sustainable UHPCs, with lower cement content, and to develop numerical models to predict the depths of carbonation and chloride ion penetration in UHPCs for different variables. To achieve this, more sustainable UHPCs will be produced using Response Surface Methodology (RSM) to optimize cement consumption while maintaining their mechanical properties. The sustainable UHPC samples will be submitted to accelerated carbonation and rapid chloride permeability tests at different ages in order to build models to predict carbonation and chloride ingress depths through time. It is expected that the results of this research will help to understand the role of different variables, such as cement content, compressive strength, and mineral additions on the durability of UHPCs. By developing durability models, it will be possible to estimate the service life of UHPC structures and evaluate the environmental impacts for their whole life cycle (cradle to gate) or to estimate the environmental impacts for their production with lower cover depths.

COMMITTEE MEMBERS:
Presidente - PETER LUDVIG
Interna - JUNIA NUNES DE PAULA
Externa à Instituição - WEINA MENG