Examinando por Autor "Gamarra, A."

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    Ítem
    Efecto de la fotodegradación en la microestructura y composición química del asfalto
    (2014-05-01) Gamarra, A.; Alexander Ossa, E.; Gamarra, A.; Alexander Ossa, E.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
    En este estudio se ha investigado la influencia que tiene la foto-oxidación en el envejecimiento del asfalto. Al estar constituido en su mayoría por componentes orgánicos, este se ve afectado por las condiciones ambientales que causan la degradación de di
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    Ítem
    Thermo-oxidative aging of bitumen
    (Taylor and Francis Ltd., 2018-07-03) Gamarra, A.; Ossa, E.A.; Gamarra, A.; Ossa, E.A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
    Thermo-oxidative bitumen ageing has been commonly recognised as the main cause of asphalt cracking. The effect of thermo-oxidative ageing level on bitumen has been studied in this work by means of a simple and effective mechanical stirring process. Physical characteristics of the material as Softening Point, Penetration and Viscosity were measured to samples with different ageing conditions. Chemical changes in the material were evaluated by means of SARA fractioning to measure the effect of ageing on the fundamental components of bitumen, and Infrared Spectroscopy in order to study the changes found on the oxidation-related compounds of the material. Microstructural changes on the material were evaluated using atomic force microscopy (AFM) finding that the ageing process on bitumen increases the number and size of the phases related to asphaltenes and resins, and decreases the amount of phases related to aromatics. The changes in chemical and physical characteristics of bitumen were found to be strongly dependent on the carbonyl formation. An extension to a previously proposed oxidation kinetics model was used to predict the fast rate (transient) and constant rate (steady-state) oxidation behaviour of bitumen and its relation to physical properties. The thermo-oxidative changes suffered by bitumen are associated with increasing hardening of the material, making it susceptible to cracking when in contact with aggregate as thin films in flexible pavements. © 2016 Informa UK Limited, trading as Taylor & Francis Group.