GUIDELINES ON WHEN TO APPLY AND REMOVE SEASONAL LOAD RESTRICTIONS - DEVELOPMENT THROUGH IMPLEMENTATION . THIRD INTERNATIONAL CONFERENCE ON BEARING CAPACITY OF ROADS AND AIRFIELDS. PROCEEDINGS, NORWEGIAN INSTITUTE OF TECHNOLOGY, TRONDHEIM, NORWAY, JULY 3-5 1990. VOLUMES 1-2

The purpose of this paper is to present guidelines on when to apply load restrictions on pavements during the thawing (or critical period) after very cold weather and how long such restrictions should remain in force. Guidelines on the magnitude of load restrictions are also presented. For determining when to apply load restrictions, the following factors are often considered: (a) comparison of summer and spring pavement surface deflection data; (b) surface thickness; (c) moisture conditions; (d) subgrade type; and (e) local experience. It is recommended that load restrictions should be applied after accumulating a thawing index (TI) of about 13.9 degrees C days, which is based on an air temperature datum of -1.7 degrees C and must be applied at a TI of about 27.8 degrees C-days. Corresponding TI levels and less for thin pavements (for example 5 cm of asphalt concrete and 15 cm of aggregate base or less). The duration of the load restriction period can be directly estimated by the following relationship which is a function of the air freezing index (FI): TI is approximately equal to 0.30 (FI). The average load restriction (reduction) is about 44%. An analysis based on characterizing a pavement structure as a layered elastic system suggests a minimum load restriction level of 20%. (TRRL)

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  • Corporate Authors:

    Tapir

    Trondheim University, Gloeshaugen
    Trondheim-NTH,   Norway 
  • Authors:
    • Mahoney, J P
    • Jackson, N C
  • Publication Date: 1990

Language

  • English

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Filing Info

  • Accession Number: 00612247
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • ISBN: 82-519-1033-1
  • Files: ITRD, TRIS
  • Created Date: Aug 31 1991 12:00AM