Traditionally the structural number of a pavement has been determined from its layer thicknesses and laboratory-determined material properties. As traditional methods of laboratory testing have become expensive and not always applicable, other experimental devices are sought to provide this parameter. Preference has been given to the falling weight deflectometer (FWD) because of its non-destructive nature and speed. A number of techniques have been developed to determine structural numbers from surface deflections. In a recent study from HDM4 the available methods were evaluated on data collected in South Africa, Lesotho, Botswana, Malaysia and the Philippines. In the comparison process the structural numbers of some 240 in-service pavement structures were determined using five available approaches. The approaches include procedures utilising mechanistic backcalculation of layer moduli, relating dynamic cone penetration results to structural number and methods of using the shape of the deflection basin to infer the structural number. In the paper the approaches are discussed and compared. Recommendations are made regarding the use of various approaches based on the level of complication and the available information. (a) For the covering entry of this conference, please see IRRD abstract no. 878228.


  • English

Media Info

  • Features: References;
  • Pagination: p. 99-115

Subject/Index Terms

Filing Info

  • Accession Number: 00731428
  • Record Type: Publication
  • Source Agency: ARRB
  • ISBN: 0-86910-707-0
  • Files: ITRD, ATRI
  • Created Date: Feb 27 1997 12:00AM