Banca de QUALIFICAÇÃO: JULIANA OLIVEIRA COSTA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JULIANA OLIVEIRA COSTA
DATA : 20/12/2019
HORA: 10:00
LOCAL: Prédio 18
TÍTULO:

Alkali activated concrete with RAP aggregates as base/subbase layer of pavements 

PALAVRAS-CHAVES:

RAP, recycling, pavement, geopolymer, alkali-activation 

PÁGINAS: 40
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
SUBÁREA: Construção Civil
ESPECIALIDADE: Materiais e Componentes de Construção
RESUMO:

The pavement infrastructure comprises 16.3 million kilometres worldwide; therefore, the pavement material production and related industrial sectors are said to be responsible for 21% of the global Greenhouse Gas (GHG) emissions worldwide. Sustainable actions on materials for those pavement layers mostly consider replacing (i) natural aggregates (NA) for recycled ones and (ii) Portland cement (PC) used as binder/stabilizer with greener binders. This research investigates the possibility of incorporating recycled asphalt pavement (RAP) as aggregate replacement and alkali activated material (AAM) as Portland cement (PC) replacement on base and subbase layers.  So far, the potential utilization of RAP in cementitious matrices has concentrated primarily as aggregate replacement for OPC based concrete for rigid pavements and stabilized with pozzolanic materials (sometimes alkali-activated) for pavement layers. The combination of RAP with alkali activated matrices may be an even greener solution, given that not only the aggregate is recycled, but also PC is absent from the matrix. Properly designed AAM are stronger and more durable than PC based materials; therefore, it is very likely that the employment of RAP in AAM will result in materials which achieve the minimum requirements for road applications.  The main objective of this thesis is to determine whether alkali activated materials (AAM) containing fine and coarse RAP aggregates (as replacement for natural aggregates) can yield a material (RAP-AAM) with acceptable strength, durability and low environmental impact to be used as subbase/base layers of pavements.  It is expected that the replacement of natural aggregates (NA) with RAP will represent a decline in strength values and increase the overall porosity of the material. An increase in porosity is usually associated with a decrease on durability. However, AAM have better chemical stability than PC and therefore, RAP-AAM may meet the durability requirements of pavements. The source of aluminosilicate is an important consideration on AAM and the use of high calcium sources will likely be a more suitable alternative as it will require less activation. Different beneficiation methods will observe if it is possible to improve the properties of the RAP-AAM by increasing the exposed RAP aggregate surface or reducing the porosity of the bitumen layer on the aggregates. The environmental benefit of the selected RAP-AAM will be closely dependant on the choice of aluminosilicate; therefore, the use of minimal amount of activators and it will be calculated through life cycle assessment.  This qualifying work comprises the literature review and preliminary studies on the activation of RAP aggregates.  

MEMBROS DA BANCA:
Externo ao Programa - AUGUSTO CESAR DA SILVA BEZERRA
Interno - CONRADO DE SOUZA RODRIGUES
Interno - FLAVIO ANTONIO DOS SANTOS
Externo à Instituição - FLAVIO DE ANDRADE SILVA - PUC - RJ