Relating lab properties of high percentage RAP mixtures to field performance: the NL-LAB program

In 2008 Europe introduced the CEN standards for Asphalt Concrete. The Netherlands adopted the approach of functional requirements, rather than empirical, recipe based requirement. The experiences since 2008 showed that, although this approach allows for a better, more fundamental understanding of Asphalt Concrete, the current understanding is far from complete. Especially the effect of higher percentages (60-70%) of reclaimed asphalt was surprising, since it appeared to improve all functional requirements without the typical interrelation where an increase in stiffness corresponds with a decrease in fatigue resistance. These experiences led to the initiation of a program using the Dutch road network as a living laboratory (NL-LAB). In combination with actual laboratory research on mixes used in pavement construction projects, this program aims first of all to assess the effects of mixing and compaction on functional properties. Secondly, it tries to establish the predictive quality of lab determined functional properties for field performance. This paper describes the NL-LAB program and the results for the first four projects that are analysed. Considering the variation in the results, it is clear that more results are needed to arrive at any definite conclusions. However, the available data do show that the stiffness can be determined quite well and the values found are consistent. For the resistance against fatigue the results are fairly reproducible, but the trends are not consistent over the different projects. The resistance to moisture damage appears to be predicted fairly well from the lab data, but the variation in the individual indirect tensile tests is such that that actual value of the indirect tensile strength ratio remains to be determined. Finally, the cyclic triaxial test results vary considerably over the first two projects, but they are very consistent over the second two projects. This could be related to the mixing and compaction used in the different projects.

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: 01597159
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Apr 22 2016 11:18AM