Performance review of foamed bitumen pavement in Ethiopia

The introduction of new technologies in areas where they have not been used before can lead to a rejection of an otherwise good technique if failure is observed on first use. It is on this basis that any causes of failure must be clearly understood and documented. Foamed Bitumen stabilisation has been used successfully in many countries such as New Zealand and South Africa. Experience from these countries shows that pavements stabilised with foamed bitumen have performed very well and in some cases beyond expectations. The technique is becoming increasing popular in these and other countries due to its low energy requirements, in-situ application and the ability to stabilise low quality materials with high fines content. These advantages are attractive to the Ethiopian road sector since currently there is a huge programme for rehabilitation and expansion of the road network. In Ethiopia, the first use of foamed bitumen was in the construction of the 65km section of Ambo – Gedo on the A4 trunk road which connects Addis Ababa to the Western part of the country. Existing design and construction guidelines have made the use of this technique familiar and easy. However, the section has shown several defects within the first 5 years despite adequate design parameters achieved. Field and laboratory pavement investigation and study of the design and construction records were conducted to determine the origin and causes of the defects. This paper discusses the findings of the study and proposes solutions to address the existing defects. Proposals to ensure that the same mistakes do not occur in subsequent projects are also presented.

Language

  • English

Media Info

  • Pagination: 8p
  • Monograph Title: 11th Conference on Asphalt Pavements for Southern Africa: CAPSA15, 16-19 August 2015, Sun City, South Africa

Subject/Index Terms

Filing Info

  • Accession Number: 01597112
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Apr 22 2016 11:15AM