FROST ACTION AND LOAD-CARRYING CAPACITY EVALUATION BY DEFLECTION PROFILES

THE EXPERIMENTAL USES ARE DESCRIBED OF A BENKELMAN BEAM WITH A HELMER RECORDER ATTACHED AS A MEANS OF MEASURING THE CHANGES IN LOAD-CARRYING CAPACITY OF FLEXIBLE PAVEMENTS THAT OCCUR AS A RESULT OF FROST ACTION. AN ATTEMPT WAS MADE TO CORRELATE THE VALUES OF LOAD-CARRYING CAPACITY AS DETERMINED BY THE USE OF THE WELL ESTABLISHED PLATE BEARING TEST WITH SIMILAR LOAD-CARRYING CAPACITIES AS DETERMINED BY THE USE OF THE BENKELMAN BEAM WITH THE HELMER RECORDER ATTACHED. IT IS CONCLUDED THAT THE BENKELMAN BEAM WITH HELMER RECORDER ATTACHED IS A PRACTICAL AND CONVENIENT INSTRUMENT TO USE FOR RAPID EVALUATION OF THE LOAD-CARRYING CAPACITY OF FLEXIBLE PAVEMENTS, EVEN THOUGH THE CORRELATION WITH THE WELL-ESTABLISHED PLATE BEARING TEST IS NOT OF THE HIGHEST ORDER. THE RECORDED PROFILE SHOULD BE CONSIDERED AS A VIRTUAL IMAGE OF A LONGITUDINAL SECTION THROUGH THE ROAD SURFACE BETWEEN THE DUAL WHEELS AT THE INSTANT THAT THEY STRADDLE THE PROBE POINT. MEASUREMENTS OF THE MAXIMUM DEFLECTION AND MAXIMUM INITIAL RATES OF DEFLECTION DESCRIBE RECOVERY TRENDS FROM FROST ACTION THAT ARE SIMILAR TO THOSE OBTAINED BY USE OF THE PLATE BEARING TEST, BUT THE MAXIMUM FLECTION RECOVERY TREND INDICATES THAT IT IS A MORE CRITICAL MEASUREMENT OF THE EFFECT OF FROST ACTION UPON LOAD-CARRYING CAPACITY. WITH RESEARCH IN PRACTICAL AREAS THAT ARE SHOWING DISTRESS, THE FOLLOWING SHOULD BE DETERMINED: (1) CRITICAL LIMITS FOR THE MAXIMUM FLECTION PER FOOT OF FLEXIBLE PAVEMENT THAT THE PAVEMENT CAN TAKE AT TEMPERATURES NEAR OR BELOW FREEZING, AND (2) SIMILAR CRITICAL LIMITS FOR THE MAXIMUM TOTAL DEFLECTION AND MAXIMUM INITIAL RATES OF DEFLECTION. FROM AN EMPIRICAL APPROACH TO THE PROBLEM, IT APPEARS THAT REASONABLY APPROXIMATE CONSTANTS CAN BE DETERMINED FOR USE IN CONVERTING DEFLECTION OF FLEXIBLE PAVEMENT MEASUREMENTS INTO REASONABLE ESTIMATES OF PLATE BEARING VALUES AND INTO RATINGS OF ROADS IN TONS PER AXLE. /AUTHOR/

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrbbulletin/218/218-001.pdf
• Supplemental Notes:
  • No 218, pp 1-10, 12 FIG Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Preus, C K
  • Tomes, L A
• Publication Date: 1959

Media Info

• Monograph Title: Frost effects in soils and on pavement surfaces
• Serial:
  • Highway Research Board Bulletin
  • Issue Number: 218
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Bearing capacity; Benkelman beam; Correlation analysis; Deflection; Deflection tests; Flexible pavements; Frost action; Pavements; Plate bearing test; Recording instruments
• Old TRIS Terms: Frost action effects; Pavement deflection; Recorders; Test results
• Subject Areas: Data and Information Technology; Geotechnology; Highways; Pavements;

Filing Info

• Accession Number: 00206983
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Apr 28 1994 12:00AM