ANALYSIS OF DEFLECTION DATA FROM THE AASHO ROAD TEST

THE REPORTS FROM THE AASHO ROAD TEST CONTAIN A LARGE LAYER, BUT THE VERY COMPLICATED FORMULA FOR THE DEFLECTION MAKES THIS VERY DIFFICULT. INSTEAD OF THIS AN APPROXIMATION IS OBTAINED BY USE OF A MORE SIMPLE FORMULA, WHICH MAY BE USED, WHEN THE SUBGRADE IS SOFT. THIS LEADS TO THE USE OF A THICKNESS INDEX OF THE SAME FORM AS IN THE REPORTS FROM THE AASHO ROAD TEST. THE AGREEMENT BETWEEN MEASURED AND CALCULATED DEFLECTIONS IS NOT TOO GOOD, BUT A SURVEY OF DATA SYSTEM 4199-F FROM THE AASHO ROAD TEST SHOWS THAT MOST OF THE THINNEST SECTIONS HAD DEVELOPED CRACKS BEFORE THE DEFLECTION MEASUREMENTS WERE CARRIED OUT. A REGRESSION ANALYSIS ON THE RESULTS FROM THE UNCRACKED SECTIONS LEADS TO A SATISFACTORY AGREEMENT BETWEEN MEASURED AND CALCULATED DEFLECTIONS. USING THE VALUES FOR YOUNGS MODULUS FOUND BY THE REGRESSION ANALYSIS THE SUBGRADE PRESSURE AT THE START OF THE TEST HAS BEEN CALCULATED FOR ALL THE TEST SECTIONS AND IT IS SHOWN THAT SERVICE LIFE OF THE TEST SECTIONS CORRELATE WITH THE SUBGRADE PRESSURE. THIS ANALYSIS OF SOME RESULTS FROM THE AASHO ROAD TEST THUS SUPPORT THE USE OF THE THEORY OF ELASTICITY AS A BASIS FOR A DESIGN METHOD IN WHICH THE SUBGRADE PRESSURE AS WELL AS THE STRESSES IN THE PAVEMENT ARE CONSIDERED. (AUTHOR)

• Supplemental Notes:
  • Preprint VoL, PP 100-106, 5 FIG, 2 TAB
• Authors:
  • Kirk, J M
• Conference:
  • Intl Conf Struct Design Asphalt Pvmts
• Publication Date: 1967-1

Subject/Index Terms

• TRT Terms: Analysis; Deflection; Elasticity (Mechanics); Flexible pavements; Modulus of elasticity; Pavement design; Pavement layers; Pressure; Regression analysis; Subgrade (Pavements); Test sections
• Identifier Terms: AASHO Road Test
• Uncontrolled Terms: Data
• Old TRIS Terms: Elastic theory
• Subject Areas: Data and Information Technology; Highways; Pavements;

Filing Info

• Accession Number: 00205482
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 1 1994 12:00AM