PREDICTING PERFORMANCE OF BITUMINOUS SURFACED PAVEMENTS

A THEORETICAL METHOD WAS DEVELOPED FOR PREDICTING STRESSES, STRAINS, AND DEFLECTIONS IN MULTI-LAYERED PAVEMENT SYSTEMS SUBJECTED TO REPEATED LOADINGS USING REALISTIC TIME DEPENDENT MATERIAL PROPERTIES. AS THE FIRST STEP IN THE DEVELOPMENT OF A SUITABLE THEORY, ELASTIC LAYERED THEORY WAS EXTENDED TO INCLUDE NUMERICAL SOLUTIONS OF FOUR-LAYER PAVEMENT SYSTEMS SUBJECTED TO UNIFORM, CIRCULAR, SURFACE LOADING. THE LAYERED PAVEMENT SYSTEM WAS APPROXIMATED BY A SERIES OF ISOTROPIC, HOMOGENEOUS, LINEARILY ELASTIC LAYERS INFINITE IN HORIZONTAL EXTENT. EACH LAYER INTERFACE WAS ASSUMED TO BE PERFECTLY ROUGH. BODY AND INERTIA FORCES WERE NEGLECTED. STRESSES, STRAINS, AND DEFLECTIONS AT A NUMBER OF POINTS WERE CALCULATED FOR SEVERAL GEOMETRIES OF TWO, THREE AND FOUR-LAYER PAVEMENT SYSTEMS WITH AND WITHOUT THE INCLUSION OF A LOW MODULUS (INSULATING) LAYER. REALISTIC TIME DEPENDENT MATERIAL PROPERTIES WERE SELECTED FOR ASPHALT SURFACE, LOW MODULUS (INSULATING) LAYER, AND CLAY SUBGRADE MATERIALS FROM THE RESULTS OF REPEATED AXIAL LOAD AND CREEP TESTS, AND EXPRESSED IN TERMS OF EQUIVALENT LINEAR VISCOELASTIC MATERIALS. A MULTIPLE ELEMENT KELVIN MODEL WAS USED TO REPRESENT THE EQUIVALENT TIME DEPENDENT RESPONSE OF THE MATERIALS AND THE MODEL CONSTANTS WERE EVALUATED BY MEANS OF A COLLOCATION METHOD. THE GRANULAR MATERIAL COMPRISING THE BASE WAS ASSUMED TO BEHAVE AS A LINEAR ELASTIC SOLID, ALTHOUGH THE THEORY CAN ACCOMMODATE A TIME DEPENDENT RESPONSE IN THE BASE, IF DESIRED. THE SOLUTION TO THE PROBLEM OF A VISCOELASTIC LAYERED SYSTEM SUBJECTED TO A STEP LOADING WAS OBTAINED BY APPLYING THE CORRESPONDENCE PRINCIPLE TO THE ASSOCIATED ELASTIC SOLUTION PREVIOUSLY DESCRIBED. NUMERICAL RESULTS WERE OBTAINED SHOWING THE VARIATION OF STRESSES, STRAINS, AND DEFLECTIONS WITH THE NUMBER OF LOAD APPLICATIONS FOR SEVERAL PAVEMENT SYSTEMS WITH AND WITHOUT A LOW MODULUS (INSULATING) LAYER. THE RESULTS OF THE THEORETICAL INVESTIGATION INDICATE THAT, FOR THE PAVEMENT SYSTEMS STUDIED, BENEFICIAL EFFECTS DERIVED FROM A SIGNIFICANT INCREASE IN THE STIFFNESS OF THE UPPER LAYERS COMPARE FAVORABLY WITH THOSE OBTAINED FROM A SUBSTANTIAL INCREASE IN PAVEMENT THICKNESS. A HIGH QUALITY BASE IS ESPECIALLY BENEFICIAL IN MINIMIZING FATIGUE-TYPE FAILURES IN ASPHALT SURFACINGS. PREDICTIONS OF RESILIENT DEFLECTIONS AND RUTTING OF ASPHALT PAVEMENTS IN THE AASHO ROAD TEST COMPARED FAVORABLY WITH OBSERVED VALUES. THUS, THE NEW THEORY SHOWS PROMISE OF PROVIDING A RATIONAL BASIS FOR DESIGNING PAVEMENTS USING LABORATORY TESTS FOR THE EVALUATION OF MATERIAL PROPERTIES.

• Supplemental Notes:
  • Preprint VoL, PP 251-276, 15 FIG, 1 TAB, 90 REF
• Authors:
  • Barksdale, R D
  • Leonards, G A
• Conference:
  • Intl Conf Struct Design Asphalt Pvmts
• Publication Date: 1967-1

Subject/Index Terms

• TRT Terms: Accelerated tests; Bituminous materials; Deflection; Deformation curve; Flexible pavements; Forecasting; Pavements; Repeated loads; Stiffness; Surface treating; Theory; Thickness; Time; Viscoelastic materials; Viscoelasticity
• Uncontrolled Terms: Pavement thickness
• Old TRIS Terms: Bituminous surfacing; Pavement deflection
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 00205488
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 4 1994 12:00AM