Banca de DEFESA: ANDRÉ LUIZ SANTOS PATRIOTA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ANDRÉ LUIZ SANTOS PATRIOTA
DATE: 01/09/2023
TIME: 08:00
LOCAL: Pós-Graduação Engenharia Civil
TITLE:

Effect of The Particle Size of Glass Waste Used as Supplementary Material on the Physical and Microstructural Properties of Portland Cement Pastes

KEY WORDS:

glass powder; alkaline equivalent; binary mixtures; physical indices; compressive strength; portlandite consumption; microstructural analysis

PAGES: 171
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

Portland cement (PC) manufacturing is among the industrial activities that emit the most harmful gasses into the atmosphere. Its replacement by alternative supplementary cementitious materials (SCM) is a timely research issue to address climate change-related constraints. There is a consensus in the literature on the possibility of using soda lime glass powder (PV) as SCM. However, studies with this bias, whether unitary or binary additions, do not consider the harmful potential of excess alkalis present in PV. In addition, little consideration is given to grind operations and more detailed contributions on the influence of glass particle size. This study proposes a formulation method for unit and binary substitutions containing PV, active silica (AS), metakaolin (MC) that takes into account the maximum amount of alkali in the mixtures. In this context, the unitary and binary additions were analyzed in isolation and employed in the production of pastes that were characterized in anhydrous, fresh and hardened state. For this study, approximately 2 kg of PV in the ranges (45x75, 25x45, < 45 and < 25 μm) were prepared in a porcelain ball mill. With X-ray diffraction and infrared spectroscopy, the same hydration products found in the reference sample were observed in the pastes with unit and binary substitutions. The amount of portlandite was evaluated by thermogravimetric analysis. Portlandite consumption after 7 and 56 days was affected by both the particle size of PV and the nature of the substitution. Pastes produced with PV < 45 μm and < 25 μm the two finest PV particle sizes showed the same level of compressive strength as the reference pastes, and those with unit replacement (SA and MC). It was observed that the compressive strength depends simultaneously on the void ratio and portlandite consumption. Scanning electron microscopy in conjunction with energy dispersive spectroscopy was useful to show the effect of particle size on the pozzolanic reactivity of PV. It was possible to conclude that formulation of binary additions was a satisfactory method for dosages where alkali control is required. It was verified that small concentrations of PV were sufficient to contribute to the binary additions. This study provides new directions to boost the use of ultrafine waste glass as SCM.

COMMITTEE MEMBERS:
Presidente - 1152919 - ARNALDO MANOEL PEREIRA CARNEIRO
Externa à Instituição - JANAIDE CAVALCANTE ROCHA - UFSC
Externa à Instituição - MARYLINDA SANTOS DE FRANCA - TUM
Externa ao Programa - 3100969 - NATHALIA BEZERRA DE LIMA - nullExterno à Instituição - WESLEI MONTEIRO AMBROS - UFRGS
Externo à Instituição - ÂNGELO JUST DA COSTA E SILVA - UPE