Optimization and characterization of asphalts modified with isocyanate modifier

Tellez Vega, Esteban Felipe

Optimization and characterization of asphalts modified with isocyanate modifier

dc.contributor.advisor	Jasso, Martin
dc.contributor.author	Tellez Vega, Esteban Felipe
dc.contributor.committeemember	Sleep, Sylvia
dc.contributor.committeemember	Khoshnazar, Rahil
dc.date	2024-11
dc.date.accessioned	2024-04-24T16:41:06Z
dc.date.available	2024-04-24T16:41:06Z
dc.date.issued	2024-04-22
dc.description.abstract	With the increase of traffic volumes, higher axle loads and harsh climate conditions, the paving industry relies on the use of polymer modified asphalts. With the progress of polymer science and technology, new polymer modified asphalt technologies have emerged. Among the most innovative modification technologies belong the use of B2last, a commercial product of BASF. Unlike other polymer modifiers, B2last is characterized as reactive mono- and oligomeric aromatic diisocyanate. Besides the formation of covalent bonds with polar species present in asphalt, the conversion of B2last into polymer could also be anticipated. In this thesis, a soft conventional asphalt was modified by B2last. The development of modification technology and the effect of B2last on the properties of asphalt was investigated by Superpave binder specification and Fourier-transform infrared spectroscopy (FTIR). The initial Superpave results suggested that B2last had a significant effect on maximum service temperature and resistance to the effects of short-term aging. This could be attributed to the reactive nature of the modification, as the additional oxygen and high temperatures could have led to further conversion of B2last and formation of heavier molecules. Due to the poor performance of B2last modified asphalt in the Multiple Stress Creep and Recovery experiment, the formulations of ternary modified asphalts containing B2last and vulcanized SBS were studied via the Design of Experiments. A positive interaction between the materials was found at high service temperatures, where the thermo-oxidative sensitivity of crosslinked SBS was generally mitigated by the presence of B2last. Lastly, the effect of B2last in paving mixes was evaluated and compared to the performance of hot mix asphalts containing asphalts prepared by a variety of modification technologies. The formulations included asphalt modified with B2last, vulcanized SBS, straight run asphalt with low Pen grade, catalytically oxidized asphalt, and optimized ternary blends containing SBS and B2last. While the samples modified with only vulcanized SBS had a superior performance in several tests, some of the ternary blends showed similar properties while using reduced amounts of total modifiers by weight, leading to the potential formulation of superior performing asphalt mixes with a reduced total content of polymer modifiers.
dc.identifier.citation	Tellez Vega, E. F. (2024). Optimization and characterization of asphalts modified with isocyanate modifier (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	https://hdl.handle.net/1880/118481
dc.identifier.uri	https://doi.org/10.11575/PRISM/43323
dc.language.iso	en
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject.classification	Engineering--Civil
dc.title	Optimization and characterization of asphalts modified with isocyanate modifier
dc.type	master thesis
thesis.degree.discipline	Engineering – Civil
thesis.degree.grantor	University of Calgary
thesis.degree.name	Master of Science (MSc)
ucalgary.thesis.accesssetbystudent	I do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.