USE OF ROAD RATER DEFLECTIONS IN PAVEMENT EVALUATION

There is a need to predict the future performance of pavements by using deflections measured at any time so that deflection data can be used to determine the strategy for pavement maintenance. The road rater is relatively new instrument for evaluating pavement performance. This paper presents some basic principles of road rater operation, its method of measuring pavement response, and criteria for evaluating the future performance of flexible pavements that contain bituminous concrete base courses. The response of experimental pavements to 80-kN (18000-lb) axle loads and road rater loading is analyzed and is related to the actual performance of the experimental pavements. A model 400 road rater was operated at a frequency of 25 Hz. The BISAR computer program was used to obtain spring pavement temperature and subgrade moisture condition. Critical responses analyzed include maximum vertical compressive strain at the top of the subgrade, maximum tensile strain at the bottom of the base course, and maximum surface deflection. Based on the results of the analysis, equations are developed of critical responses to 80-kN axle loads from the road rater deflection basin. A permissible ratio of surface curvature index to maximum deflection is also established based on the fatigue property determined in the laboratory. This value may be used to evaluate pavements for rehabilitation purposes. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 32-39
  • Monograph Title: Pavement surface properties, evaluation, and shoulders
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00189507
  • Record Type: Publication
  • ISBN: 0309028051
  • Files: TRIS, TRB
  • Created Date: Apr 12 1979 12:00AM