The Effect of the Interaction between Bituminous Seals and their Substrates on the Performance of Road Pavements in Tropical Environments

The performance of pavements is governed by the characteristics of the materials of the individual pavement layers, the support provided by underlying layers, and the overall pavement strength to withstand the traffic stresses. These factors vary seasonally and in the long-term as the materials age.Bituminous seals are an expensive layer of the pavement system and thus their failure should be minimised by proper selection of the appropriate technology combination. An understanding of the mechanism by which failure is induced through the use of inappropriate combinations of seal and substrate is important to ensure longevity of the pavement. This paper examines 6 case studies to demonstrate cases where substrate failure was initiated by failure of the seal and where seal failure is initiated by changes in the substrate conditions. The effect of climatic factors such as rainfall and poor drainage, and bitumen aging are considered. Bitumen aging is severe under tropical conditions. Failure mechanisms are postulated for each of the case studies examined.As a result of the examination of these case studies, it was apparent that the choice of seal and substrate combinations play an important role in pavement performance. Historically weak seals such as sand seal performed better when laid on strong substrates/bases. WPavements comprising moisture susceptible substrates induced defects on thin seals, although seals with thicker bitumen films, such as Otta seal performed comparatively better when used on those substrates.

Language

  • English

Media Info

  • Media Type: Web
  • Features: Figures; References; Tables;
  • Pagination: 17p

Subject/Index Terms

Filing Info

  • Accession Number: 01763813
  • Record Type: Publication
  • Report/Paper Numbers: TRBAM-21-00309
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 23 2020 11:12AM