IS THE MEASURED DEFLECTION OF A FLEXIBLE PAVEMENT A RELIABLE GUIDE TO LIFE PREDICTION AND OVERLAY DESIGN?

The author suggests that the current UK method of basing maintenance decisions on the transient deflection under a standardised moving wheelload could be unreliable. Case histories are used to show how correcting deflection to a standard temperature of 20 degrees C can produce significantly different predictions of remaining life. Studies have shown that curves used to correct deflection were based on seasonal and not diurnal temperature changes. Seasonal temperature/deflection decreases with the age of the pavement primarily due to the hardening of bitumen with time but compaction under traffic may play a small part. Deflection/life contours used to estimate pavement residual life were determined from experimental sites that were consciously under-designed with respect to sub-base quality and to base and surfacing thicknesses in order to produce results in a reasonable time. An example is quoted to show how deflection measurements and the deflection/life contours of a pavement section indicated the need for immediate overlay or reconstruction, whereas performance contours confirmed a life span some ten to fifteen times greater. (TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/3831968
• Corporate Authors:

  D.R. Publications Limited

  Faversham House, 111 St James Road
  Croydon, Surrey CR9 2TH,   England 
• Authors:
  • Croney, D
• Publication Date: 1990-12

Media Info

• Features: References;
• Pagination: p. 24-26
• Serial:
  • Highways
  • Volume: 58
  • Issue Number: 1968
  • Publisher: Alad Limited
  • ISSN: 0142-6168
  • Serial URL: http://www.highways-mag.co.uk

Subject/Index Terms

• TRT Terms: Deflection; Measurement; Overlays (Pavements); Pavement design; Pavements; Service life
• Old TRIS Terms: Pavement deflection
• ITRD Terms: 3085: Bearing capacity; 6187: Deflectograph; 5910: Durability; 6440: Error; 132: Forecast; 6136: Measurement; 2955: Pavement
• Subject Areas: Design; Highways; Pavements;

Filing Info

• Accession Number: 00619946
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS, ATRI
• Created Date: Mar 31 1992 12:00AM