Ageing characteristics of warm mix asphalt binders modified with F-T wax: benefits for efficient application and adequate performance

The use of rheology modifying additives in asphalt mixes for reducing the mix production temperature and/or increasing the reliability of the compaction process in order to obtain durable pavements, is state of the art. F-T wax decreases the viscosity of bitumen and imparts lubricity above its melting temperature range, resulting in improved workability and compactibility of the asphalt mixes. The wax is thoroughly mixed with the bitumen which poses the question of influencing physico-chemical properties of the binder, such as aging properties. In order to evaluate the potential effects on aging, three bitumen samples were prepared in the laboratory: a bitumen 50/70 as control sample and the 50/70 mixed with two F-T waxes of different chemical composition. The binders were evaluated in the fresh state as well as short-term aged (by RTFOT) and long-term aged (by PAV) states respectively. Besides effects on mechanical/rheological properties, the main focus was the detection of ageing effects on the chemical and colloidal composition of the binders. The aging processes of the bitumen were only slightly influenced by the added F-T waxes, whilst one of the two wax types even yielded some minor advantages. These differences between the relative performances of the two wax types can be ascribed to chemical differences between them. The observed influences of the F-T waxes on the chemical composition are minor compared to the variety found for bitumens from different crude origins. The results show that the chemical composition as well as the aging properties are predominantly affected by the bitumen characteristics, whereas effects of F-T wax do not compromise the aging properties of the binder.

• Authors:
  • Simnofske, D
  • Mollenhauer, K
  • OELKERS, C
  • Butz, T
• Conference:
  • Conference on Asphalt Pavements for Southern Africa (CAPSA15), 11th, 2015, Sun City, South Africa
• Publication Date: 2015-8

Language

• English

Media Info

• Pagination: 11p
• Monograph Title: 11th Conference on Asphalt Pavements for Southern Africa: CAPSA15, 16-19 August 2015, Sun City, South Africa

Subject/Index Terms

• TRT Terms: Aging (Materials); Binder content; Bitumen; Pavement performance; Rheology
• Uncontrolled Terms: Pavement technology
• ATRI Terms: Ageing; Binder content; Bitumen; Pavement performance; Rheology
• Subject Areas: Design; Geotechnology;

Filing Info

• Accession Number: 01597114
• Record Type: Publication
• Source Agency: ARRB
• Files: ATRI
• Created Date: Apr 22 2016 11:15AM