Banca de DEFESA: AMANDA MARQUES LOPES ESTOLANO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : AMANDA MARQUES LOPES ESTOLANO
DATE: 28/08/2024
TIME: 14:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

Development of sustainable cementitious composites with mechanically treated construction and demolition waste in the mixer: analysis of properties, influence of aggregate roughness, and toxicity aspects

KEY WORDS:

Concrete; Mortar; Waste; Mechanical treatment; Roughness.

PAGES: 112
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

The construction industry is recognized as one of the main generators of waste due to construction and demolition processes. Reuse within the industry itself is still limited due to the variability of these wastes for applications in cementitious materials. The mechanical strength of concrete and mortars is influenced by the characteristics of the aggregates, including shape, composition, and roughness. Recycled aggregates have a more porous surface and variable composition compared to natural aggregates, contributing to the interlocking of the system and increasing the transition area between the paste and the aggregate. This study presents a quick and feasible alternative for mechanical treatment of waste to improve its properties when incorporated into concrete and mortars. The research methodology consisted of using mechanical treatment of aggregates with the aid of a concrete mixer by completely replacing natural aggregates with treated recycled aggregates, investigating their potential through compression strength tests, ultrasonic wave propagation, surface morphology, and chemical and mineralogical composition. The roughness of the aggregates was varied through mechanical treatment and manual sanding to obtain different levels and was quantified using laser confocal microscopy. Through the mortar immersion method, developed in this study, the interfacial transition zone was analyzed and visualized using scanning electron microscopy. The results indicate that the suggested mechanical treatment produced aggregates with improved properties and that, for high roughness levels, the pasteaggregate adhesion is compromised with the appearance of voids in the interfacial transition zone. The use of surface treatments for a slight increase in roughness can be a strategy for improving the mechanical properties of concrete.

COMMITTEE MEMBERS:
Presidente - 3100969 - NATHALIA BEZERRA DE LIMA
Externo à Instituição - ALEXANDRE DUARTE GUSMAO - UPE
Externa à Instituição - ELIANA CRISTINA BARRETO MONTEIRO - UPE
Externo à Instituição - MANOEL HENRIQUE DA NÓBREGA MARINHO - UPE
Externa à Instituição - YÊDA VIEIRA PÓVOAS - UPE