The Measured and Theoretical Response of the Kansas Perpetual Pavement Structures

In order to validate the perpetual pavement concept for Kansas highways, four experimental pavement sections designed according to the perpetual pavement concept were built on the US-75 highway in Northeast Kansas in 2005. The sections were instrumented with strain gauges and stress cells to measure strains and stresses at the bottom of the asphalt concrete base layer. Pavement response measurements under known truck loads were carried out in seven sessions between July 2005 and October 2007 with a loaded truck. The obtained response values showed that longitudinal and transverse strains were almost always below 70 microstrains, the average endurance limit mentioned in the literature, which suggests that the perpetual pavement designs are valid. The measurements also showed that temperature and vehicle speed have significant effects on the response of asphalt pavements. It was also observed that transverse strains were always larger than longitudinal strains, which was contradictory to the current knowledge. The field strain measurements coupled with flexural fatigue testing conducted in the laboratory indicate that the optimum solution for obtaining a long-lasting full-depth asphalt pavement structure is to use a binderrich asphalt mix in bottom lift of the base layer. This mix was designed with a target air void content of 3% and resulted in an increase in binder content of 0.5% compared to the conventionally designed mix. The linear elastic software EVERSTRESS and the finite element software ABAQUS were used to theoretically predict the pavement responses using linear elastic and visco-elastic models, respectively. The results from the linear elastic analyses were similar to the measured pavement response values, except for vertical stresses at the top of the lime-treated embankment layer; the measured stresses were smaller than the computed stresses. On the other hand, the strains calculated by the visco-elastic finite element model (FEM) employing a quasi-static approach were smaller than the measured values. The FEM was also run as an elastic model and the results were similar to the ones from EVERSTRESS, suggesting that the FEM mesh was built correctly but the visco-elastic modeling based on the quasi-static analysis was not effective for modeling the response of thick asphalt pavement structures under the moving vehicles.

Language

  • English

Media Info

  • Media Type: Web
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 256p

Subject/Index Terms

Filing Info

  • Accession Number: 01142626
  • Record Type: Publication
  • Report/Paper Numbers: KS-09-2
  • Contract Numbers: C1594
  • Files: TRIS, STATEDOT
  • Created Date: Oct 27 2009 12:47PM