THE USE OF THE DEFLECTION BEAM IN EVALUATING THE STRENGTH OF FLEXIBLE ROAD PAVEMENTS

In this report the use of deflection techniques for pavement evaluation and the design of road strengthening measures in discussed. The long term performance of flexible pavements can be determined by the magnitude of the transient deflections which occur under traffic. Deflection histories can be prepared for any type of construction by relating the deflection measured under a standard wheel load to (A) The age of the road expressed in terms of the cumulative total of equivalent standard 8200kg (18,000lb) axle loads and (B) the condition of the pavement in terms of rutting and cracking. Deflection histories thus derived can be used to evaluate an existing pavement's future traffic carrying capacity and thus indicate at what time strengthening will be necessary. Relationships can also be derived for the reduction in deflection brought about by overlays of different types and thicknesses. These, combined with deflection histories of overlaid pavements, can be used to prepare recommendations for overlay thickness to achieve any required extension of pavement life. The deflection beam which is used to measure deflections is discussed in detail. The results of experiments carried out to investigate some of the parameters which influence deflections as measured by the deflection beam are presented. A recommended standard procedure for using the deflection beam is included in an appendix to the report. /TRRL/

• Corporate Authors:

  An Foras Forbartha

  St Martin's House, Waterloo Road
  Dublin 4,   Ireland 
• Authors:
  • Jermyn, T M
• Publication Date: 1974-1

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: 46 p.

Subject/Index Terms

• TRT Terms: Axle load force; Bearing capacity; Benkelman beam; Deflection; Flexible pavements; Strength of materials
• ITRD Terms: 1757: Age; 3085: Bearing capacity; 6105: Benkelman beam; 5586: Deflection; 2944: Flexible pavement; 132: Forecast; 2755: Highway; 1088: Inland waterway; 5544: Strength (mater); 3096: Strengthening (pavement); 755: Traffic
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 00081365
• Record Type: Publication
• Source Agency: An Foras Forbartha Teoranta
• Report/Paper Numbers: No. RC 110 Series
• Files: ITRD, TRIS
• Created Date: May 1 1975 12:00AM