This study investigates the applicability of theoretical design models by means of comprehensive experiments on fully monitored motorway trial sections. In two types of construction--one with full depth asphalt and one with a sand-cement sub-base--strains at different levels in the structures, surface deflections and soil pressures were measured under a variety of conditions of temperature and of load, speed and lateral position of the loading vehicle. Both test sections were constructed in stages. The paper gives representative results of measurements for two stages of construction of the pavements. Material properties of subgrade, sand cement and asphalt and the thicknesses of the layers were measured both in situ and in the laboratory. These data were then introduced into the BISAR computer program, based on linear elastic multi-layer theory, to calculate values of strains, deflections and soil pressures corresponding to the measured quantities and the results have been compared with one another. In addition, BISAR computations have been made to investigate the influence of a variation in test parameters (moduli, Poisson's ratios, shape and stress distribution of wheel contact area, etc.). The widths (durations) of recorded regular strain signals were used to characterize the loading time. Measured and computed quantities are mostly presented as a function of the stiffness modulus of the asphalt (incorporating the effect of temeprature and loading time). Generally, the results showed increasing scatter at lower asphalt moduli. Computations showed that variations in test conditions also have their strongest influence at low asphalt stiffness. In some cases a stronger difference between longitudinal and transverse strain was found as compared with the computed values. On the whole, measured values of strains, deflections and soil pressures showed good agreement with the corresponding computed values, particularly with higher asphalt moduli. /Author/

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 75-98

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Filing Info

  • Accession Number: 00170208
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Mar 14 1978 12:00AM