PRACTICAL APPLICATION OF THE FALLING WEIGHT DEFLECTOMETER IN EVALUATION OF PAVEMENTS. SINO-BRITISH HIGHWAYS AND URBAN TRAFFIC CONFERENCE. PAPERS PRESENTED AT THE CONFERENCE HELD IN BEIJING 17TH-22ND NOVEMBER 1986

This paper describes a procedure for the non-destructive evaluation of the structural condition of a road pavement that has been used and promoted by the Halcrow Pavement Group, a cooperative project between Netherland pavement consultants and Sir William Halcrow and Partners. This method is based on falling weight deflectometer tests, the assessment of layer moduli using these test results, and the calculation of stresses and strains in the pavement. Using this approach, it is clear that the evaluation procedure matches closely the mechanistic design procedure presented in TRRL laboratory report 1132 (see IRRD 280375). The evaluation procedure also incorporates a probabilistic treatment of pavement condition, because local conditions can differ quite considerably from 'standard conditions'; as a result, in situ deterioration can be modelled carefully. 'standard' overlay design procedures, that are based on limiting stresses and strains in the existing pavement, are checked against their susceptibility to reflective cracking. The authors believe that the techniques presented here constitute a powerful tool for analysing pavement condition, for planning the planning of maintenance, and for the allocation of maintenance budgets. (TRRL)