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Formulation development and thermorheological properties of crumb rubber/eva modified bitumen

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dc.contributor.advisor Hlangothi, Percy
dc.contributor.advisor Woolard, Chris
dc.contributor.author Nare, Keith Dumisani
dc.date.accessioned 2017-10-12T10:49:17Z
dc.date.available 2017-10-12T10:49:17Z
dc.date.copyright 2016
dc.date.created 2017-10
dc.date.issued 2016
dc.date.submitted 2017-04-08
dc.identifier.uri http://hdl.handle.net/10907/1512
dc.description.abstract The study deals with the formulation development and thermorheological properties of crumb rubber/ethylene vinyl acetate (EVA) modified bitumen with the aim of optimizing the amount of crumb rubber and EVA loadings in bitumen based on thermorheological parameters complex shear modulus, phase angle and rutting parameter. In the modified binders EVA offers plastomer properties whereas the crumb rubber confers elasticity to the bitumen. 13.75% crumb rubber and 2.5% EVA loadings based on aging indices gave the best optimized mixture. The thermorheological behaviour of the best optimized mixture was compared to industrial grade EVA (AP-1) and crumb rubber (AR-1) modified bitumen. Improving aging behaviour of the bitumen was evaluated using four antioxidants: carbon black, hydrated lime, Irganox 1010 and Irgafos 168. The least aging indices at 58˚C and 64˚C were obtained from a 1:1:1 Irganox 1010/hydrated lime/carbon black mixture. SARA (saturates, aromatics, resins and asphaltene) analysis gave the chemical background for application of antioxidants to reduce the propensity of short term aging. To further improve the EVA/crumb rubber optimized mixture for workability FT wax (Sasobit®) was assayed at loadings from 0-2.5%. This was done to match the EVA content and maintain the original maximum loading of 2.5% in the optimized mixture. The phase change abilities of FT wax owing to the high latent heat enabled co-crystallization with the EVA with the elastomeric backbone of crumb rubber acting as support material. The energy-sustainability nexus was found to have worked at less than 1% loading of FT wax in the EVA/crumb rubber modified bitumen. Response surface methodology approach to all the sections of work was used to come up with the optimized mixtures based on rheological parameters complex shear modulus, phase angle and rutting parameter at test temperature 64˚C. The interaction chemistry of bitumen, crumb rubber, EVA and FT wax was found to be first and second order in all cases involving individual contributions and co-interaction amongst the factors. Project costing for each section of work (optimizing section, antioxidant section and FT wax section) was conducted involving the raw materials used, equipment used, labour involved and other costs incurred for all the project work. en_US
dc.description.sponsorship National Research Foundation en_US
dc.format.extent 163 p. en_US
dc.format.medium pdf en_US
dc.language.iso en en_US
dc.publisher Nelson Mandela Metropolitan University en_US
dc.relation.requires Adobe Acrobat Reader en_US
dc.relation.uri http://hdl.handle.net/10948/11974 en_US
dc.rights Nelson Mandela Metropolitan University en_US
dc.subject Crumb rubber en_US
dc.subject Bitumen en_US
dc.subject Vinyl acetate en_US
dc.title Formulation development and thermorheological properties of crumb rubber/eva modified bitumen en_US
dc.type Thesis en_US
dc.rights.holder Nelson Mandela Metropolitan University en_US
dc.contributor.orcid 0000-0001-7834-6851 en_US


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