Evaluation of Airport Pavement Designs for Seasonal Frost and Permafrost Conditions

Abstract

In recent years, the Alaskan Region of the Federal Aviation Administration (FAA) reported performance issues with some flexible airport pavements. The issues were attributed to changes in the thermal regime of the permafrost layers resulting from a warming trend. The poor pavement performance was also caused by such factors as improper design and construction. The FAA Airport Technology Research and Development Branch selected three runways with an asphalt surface from three airports in Alaska and reviewed the pavement failures, design, and construction histories to determine the causes and contributing factors of flexible pavement performance issues. The goal was to determine if and where modifications to FAA guidance concerning design and construction in frost and permafrost zones were needed. This paper focuses on identifying frost and permafrost issues at the airports, identifying the design criteria used at the airports, and determining how closely the design criteria and construction practices followed FAA guidance. The work also recreates the pavement design for each runway, following FAA guidance in effect at the time of the design. Researchers identified areas of the FAA frost and permafrost design criteria that are silent or subject to conflicting interpretation. The paper provides recommendations for possible improvements to current FAA guidance with respect to frost and permafrost design, based on findings from the design reviews. The recommendations target Advisory Circulars 150/5320-6G and 150/5270-10H and are intended to address the design- and construction-related issues.