The use of geopolymer as supplementary binder in foamed bitumen stabilisation

Foamed bitumen recycling is a proven solution for the rehabilitation of heavily trafficked pavements that have reached their use by dates. Despite quick lime has become the preferred supplementary binder for foamed bitumen (FB), it does not work well as a slow-setting binder in hot climates. Additionally, the powdered form of lime can be easily airborne, hence causing safety and health issues. This paper presents a preliminary study undertaken to examine the use of a geopolymer, as a substitute for lime in foamed stabilisation of a Reclaimed Asphalt Aggregate (RAP). In the study, sodium silicate was mixed with fly ash and RAP (at optimum moisture content) at varying concentrations ranging from 2.5% to 6% by mass of RAP. The use of a geopolymer containing fly ash was also as an attempt to utilise the waste product, which is abundantly available in Australia. The blend containing 4.5% of geopolymer resulted in unconfined compressive strength, which is comparable to that with 3% lime. The lime stabilised blends showed no significant strength variation under different curing temperatures, whereas the geopolymer blends showed strength increase at higher temperatures during the accelerated curing. Subsequent foamed bitumen stabilisation of the geopolymer blends indicated that the resilience modulus could be maximised at 4% geopolymer. Considering the promising results, further studies on geopolymer as a supplementary binder in FB stabilisation with sodium hydroxide as an additional accelerator are warranted.

• Record URL:
  http://arrbknowledge.com
• Authors:
  • Ariyadasa, P W
  • Nataatmadja, A
• Conference:
  • AAPA International Flexible Pavements Conference, 18th, 2019, Sydney, New South Wales, Australia
• Publication Date: 2019-8

Language

• English

Media Info

• Pagination: 12p
• Monograph Title: Our everlasting roads – enabling future mobility: 18th AAPA International Flexible Pavements Conference and Exhibition, 18-21 August 2019, Sydney

Subject/Index Terms

• TRT Terms: Binders; Fly ash; Maintenance; Polymers
• Uncontrolled Terms: Foam bitumen; Materials technology (asphalt/bitumen/concrete); Pavement technology
• ATRI Terms: Binder; Fly ash; Foamed bitumen; Maintenance; Polymer; Stabilization
• Subject Areas: Maintenance and Preservation;

Filing Info

• Accession Number: 01718283
• Record Type: Publication
• Source Agency: ARRB Group Limited
• Files: ITRD, ATRI
• Created Date: Sep 26 2019 12:33PM