COVID-19 SERVICES UPDATE: Information for all alert levels, Waka Kotahi services and more

SCAM ALERTS: Report a phishing scam or learn about the latest phishing emails

ONLINE SERVICES: We currently have an issue with receiving some payments and are working to resolve this issue as quickly as possible. We apologise for any inconvenience.

EASTER WEEKEND – PLAN AHEAD: Heading away for the long weekend? Check our holiday journeys tool(external link)

SCAM ALERTS: Refund email and Vehicle licence (rego) renewal phishing emails

Back to Resources

Research Report 558 Epoxy modified bitumen chip seals

Published: | Category: Activity management , Research programme , Research & reports | Audience: Roading contractors

The research investigated aspects of the use of epoxy modified bitumen for construction of chip seals. Changes in the shear modulus, needle penetration and cohesive energy of the epoxy bitumen were used to monitor changes in the material as it cured at 35℃ and 45℃ and after accelerated ageing at 85℃ for 177 days. Wheel-tracking tests were used to determine the ability of the material to resist chip embedment and flushing. The adhesion to aggregate and resistance to water-induced stripping was also measured.

Epoxy bitumen curing rates would enable seal construction within timeframes used with conventional binders. However, although the ultimate strength of the materials was satisfactory, the curing rate would be too slow for epoxy bitumens to be useful as a lower cost substitute for commercially available high-friction surfacing binders.

Epoxy bitumen demonstrated good resistance to water stripping without added adhesion agents. Epoxy bitumen seals were highly effective in resisting chip embedment into a soft substrate and potentially might be a means of controlling or eliminating flushing in the field.

The materials used in this study were prototype formulations that may need to be optimised for low temperature flexibility. Further investigation is needed to properly characterise low temperature behaviour.

Publication details

  • Author:
  • Published: October 2014
  • ISBN/ISSN: ISBN: 978-0-478-41983-2
  • Also known as: 558