Evaluation of Rutting Characteristics for Different Climate Conditions

Using LTPP GPS-1 Data

Timothy B. Crothers

Christopher D. Hunter

 and

 Kang-Won Wayne Lee

Dept. of Civil and Environmental Engineering

University of Rhode Island

Kingston, RI 02881

(401) 874-2695

lee@egr.uri.edu

ABSTRACT

An attempt was made to evaluate the effects of climate on rutting distress of GPS-1 pavements in the Long Term Pavement Performance (LTPP) program.  This is recognized as important due to the need to understand the causes and thus how to defend against the safety hazards posed by rutting.  This permanent deformation, though previously considered only at the subgrade level of pavement structures, takes place in all layers of pavement.  Data taken from the LTPP Information Management System (IMS) was used to chart correlations between rutting and freezing conditions, moisture conditions, and temperature.

Analysis of LTPP IMS data indicates that freeze/thaw cycles and moisture conditions do have a considerable impact on rutting of pavement sections.  This is presumably due to weakening of subgrade soils, particularly of the subgrade resilient modulus.  However, it appeared that temperature has less effect on rutting.  Only at very high maximum annual temperatures can rutting be recognized in the asphalt layers.