Analysis of bio-binders for paving as a total substitute for asphalt binder.

• Ano de defesa: 2020
• Autor(a) principal: Espinosa Ruiz, Leidy Vanessa
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Biobinders; Bioligantes; Dano por umidade; Energia de superfície; Field monitoring; Moisture damage; Monitoramento em campo; Reologia; Rheology; Surface free energy; TGA
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/3/3138/tde-05112020-133903/

The bio-binders are binders, or oils, made from animal or plant biomass, which have emerged as alternative materials to reduce the dependence of the paving area on the asphalt binder. Researches in bio-binders have been focused on characterizing the material in terms of its mechanical response when blending with asphalt binder. The innovative character of bio-binders generates the need to better understand how their components interact and how this affects their performance in pavement applications. The characterization techniques applied for asphalt binders, such as rheology and performance evaluation, are also used to evaluate the behavior of bio-binders and they have shown beneficial results for mixtures when used as extenders or modifiers of the conventional asphalt binder. The bio-binders from plant sources, especially the woodbased, have shown higher potential to total replacement of asphalt binder in mixtures, when compared with that binders from animal source or vegetal oils. In this context, this thesis presents the evaluation of the potential use of two wood-based bio-binders as total replacement of asphalt binders. The materials correspond to two successive generations of the same product. The first one was evaluated at three different scales: Binder behavior, mixtures performance in laboratory and field monitoring of a pavement structure build with that biomaterial, comparing their results with that of an asphalt binder taken as reference. The second bio-binder, on the other hand, was assessed on the binder scale, studying its rheological behavior in comparison with a reference asphalt binder. Its performance was evaluated in terms of resistance to permanent deformation and fatigue, using the MSCR and LAS tests, respectively. Thermogravimetric analysis was used to determine the thermal stability and the deterioration processes of the binders involved in the research. The aging effect was assessed by monitoring changes in the rheology of the binders. The moisture sensitivity of the binders was assessed through surface free energy (SFE) parameters, based on the SFE components of the binders and the aggregates from different origin. The results suggest that the studied bio-binders represent a sustainable alternative for the asphalt binder, for the construction of flexible pavements, without affecting the mechanical performance of the mixture.