http://repositorio.ufc.br/handle/riufc/473 2026-06-10T05:12:24Z 2026-06-10T05:12:24Z Pinheiro, Lucidalva dos Santos Fernandes, Paulo Roberto Nunes Cavalcante, Rivelino Martins Nascimento, Ronaldo Ferreira do Soares, Jorge Barbosa Soares, Sandra de Aguiar Freire, José Alexander de King http://repositorio.ufc.br/handle/riufc/70714 2023-07-04T12:20:13Z 2009-01-01T00:00:00Z

Título: Polycyclic aromatic hydrocarbons from asphalt binder: extraction and characterization Autor(es): Pinheiro, Lucidalva dos Santos; Fernandes, Paulo Roberto Nunes; Cavalcante, Rivelino Martins; Nascimento, Ronaldo Ferreira do; Soares, Jorge Barbosa; Soares, Sandra de Aguiar; Freire, José Alexander de King Abstract: The asphalt binder, derived from petroleum, commonly employed in road paving contains PAHs (Polycyclic Aromatic Hydrocarbons) and a variety of other aliphatic and aromatic compounds. PAHs are pollutants that can induce health problems. This work aims to extract and characterize the PAHs in samples of asphalt binder and its concentration. Matrix solid phase dispersion was used as a technique for extraction of the PAHs. Characterization was performed employing gas chromatography and scanning tunneling microscopy. Fifteen of the priority PAHs listed by USEPA (United States Environmental Protection Agency), as well as coronene, were found in the binder samples. Tipo: Artigo de Periódico

2009-01-01T00:00:00Z Vasconcelos, Kamilla Lima Bhasin, Amit Little, Dallas N. Soares, Jorge Barbosa http://repositorio.ufc.br/handle/riufc/70712 2023-03-01T14:06:32Z 2008-01-01T00:00:00Z

Título: Medidas de adesão entre agregado e ligante asfáltico Autor(es): Vasconcelos, Kamilla Lima; Bhasin, Amit; Little, Dallas N.; Soares, Jorge Barbosa Abstract: Adhesion between the asphalt binder and the aggregate is critical to the performance and durability of asphalt mixtures. According to the literature, distresses mechanisms such as fatigue cracking and moisture induced damage are correlated to the nature and quality of adhesion between these two materials. Different mechanisms already exist to explain adhesion, but they can be summa- rized in three main groups: mechanical interlocking, physical adhesion and chemical interaction. Although discussions of isolated theo- ries and mechanisms help to clarify the understanding of adhesion, they can rarely be separated completely to each other. The physical and chemical characteristics of asphalt and aggregate will in fact determine the relevance of each of these mechanisms. This study presents the results of two procedures for adhesion measurement: (i) an indirect method based on the surface free energy components of asphalt binder and aggregate; and (ii) the determination of the enthalpy of immersion through the use of a microcalorimeter. The materials used, a gravel as aggregate and three different neat asphalts, were provided by the Strategic Highway Research Program's Material Reference Library. The results showed the capacity of the microcalorimeter in detecting possible chemical reactions together with physical adhesion. The presence of functional groups more strongly adsorbed by the aggregate surface justified the higher values of the heat of immersion. Tipo: Artigo de Periódico

2008-01-01T00:00:00Z Lucena, Maria da Conceição Cavalcante Soares, Sandra de Aguiar Soares, Jorge Barbosa http://repositorio.ufc.br/handle/riufc/70711 2023-02-09T16:52:37Z 2004-01-01T00:00:00Z

Título: Characterization and thermal behavior of polymer-modified asphalt Autor(es): Lucena, Maria da Conceição Cavalcante; Soares, Sandra de Aguiar; Soares, Jorge Barbosa Abstract: A styrene-butadiene-styrene modified asphalt cement was characterized by infrared, differential scanning calorimetry, thermogravimetric analysis and empirical tests such as ring and ball softening point, penetration and elastic recovery. After aging in the rolling thin-film oven, the polymer-modified asphalt presented structural changes relating to oxidation of the material. The infrared spectra showed an increase in hydroxyl groups and the formation of carbonyl compounds and sulphoxides. The percentage of crystallized fraction calculated from differential scanning calorimetry was 0.41%. Thermogravimetric analyses in inert and oxidative atmospheres revealed distinct events during thermal decomposition; the initial activation energies were similar, but changed as the process evolved. Tipo: Artigo de Periódico

2004-01-01T00:00:00Z Soares, Jorge Barbosa Freitas, Felipe Araújo Colares de http://repositorio.ufc.br/handle/riufc/70710 2023-02-09T16:51:55Z 2003-01-01T00:00:00Z

Título: Modelagem da formação e propagação de trincas em misturas asfálticas Autor(es): Soares, Jorge Barbosa; Freitas, Felipe Araújo Colares de Abstract: Cracking in the asphaltic layer has been pointed out as the major pavement distress in Brazilian roadways. Tipically, no consideration for the material heterogeneity has been given on previoues studies. This paper presents a numerical method of analysis, based on the thory of fracture mechanics, in which the asphaltic mixture in considered heterogeneous. The binder and the aggregates are treated as separate elements. The simulations perfomed can be verified and calibrated with simple and conventional laboratory tests. The study investigates crack formation and evolution under monotoic loading. Nevertheless, it also outlines a new method of analysis for fatigue of asphalt mixtures. It is also discussed the use of a multiscale methodology, in which the damage due to cracking in the local scale can be considered in a global analysis at the actual pavement scale. Tipo: Artigo de Periódico

2003-01-01T00:00:00Z