THE MEASUREMENT AND PREDICTION OF DEFLECTIONS AND STRAINS IN FLEXIBLE PAVEMENTS

CURRENT METHODS OF PREDICTING STRESSES, STRAINS AND DEFLECTIONS IN PAVEMENT STRUCTURES USING LINEARLY ELASTIC, VISCOELASTIC AND NON-LINEAR THEORIES ARE REVIEWED. THESE ANALYTICAL PROCEDURES ARE COMPARED WITH REFERENCE TO MEASURED AND PREDICTED BEHAVIOUR. THE APPLICATION OF A LINEAR ELASTIC ANALYTICAL TECHNIQUE TO THE STUDY OF A HEAVILY TRAFFICKED FLEXIBLE PAVEMENT IS DESCRIBED. EMPHASIS IS LAID ON THE CHARACTERIZATION OF THE PROPERTIES OF THE DIFFERENT LAYERS WHICH INCLUDE NON-COHESIVE GRANULAR, LIME STABILIZED AND BITUMINOUS STABILIZED MATERIALS. IN-SITU TEST TECHNIQUES, SUCH AS THE C.B.R. AND WAVE PROPAGATION METHODS, WERE COMBINED WITH LABORATORY DATA IN AN ATTEMPT TO DERIVE REALISTIC ELASTIC MODULI VALUES. TO EVALUATE THE APPLICABILITY OF THE THEORETICAL APPROACH, IN-SITU MEASUREMENTS, INCLUDING HORIZONTAL STRAINS AT THE BASE OF THE SURFACING LAYER, DEFLECTIONS WITH DEPTH AND TO A LESSER DEGREE BENKELMAN BEAM DEFLECTIONS AND DEHLEN CURVATURES WERE COMPARED WITH PREDICTED VALUES. IT WAS FOUND THAT THE HORIZONTAL TENSILE STRAINS AT THE BASE OF THE ASPHALT LAYER CAN BE SATISFACTORILY PREDICTED USING A LINEAR ELASTIC MULTI-LAYER COMPUTER PROGRAM. A QUALITATIVE FORECAST IS POSSIBLE IF LAYER PROPERTIES ARE KNOWN, AND A QUANTITATIVE ONE IF THE BASE LAYER CHARACTERISTICS CAN BE ADEQUATELY ASCERTAINED. VERTICAL DEFLECTION DISTRIBUTIONS CANNOT BE ACCURATELY PREDICTED BOTH IN MAGNITUDE AND IN VARIATION WITH DEPTH, BY ELASTIC THEORIES, AND NUMEROUS INVESTIGATORS HAVE RESORTED TO MORE SOPHISTICATED THEORIES TO OVERCOME THIS DEFICIENCY.

  • Corporate Authors:

    Nat Inst Road Research /S Africa

    ,    
  • Authors:
    • Freeme, C R
  • Publication Date: 1970

Language

  • English

Media Info

  • Features: Figures; References;
  • Pagination: 77 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00207661
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: TRIS, ATRI
  • Created Date: Sep 19 1972 12:00AM