Evaluation of Precut Technique to Control Thermal Cracking in Alaskan Asphalt Concrete Pavements

Abstract

Thermal cracking is one of the most prevalent pavement distresses found in Alaska and cold areas of other northern states. Previous studies indicated that precutting of thermal cracks in asphalt concrete (AC) pavements has provided promising results in controlling pavement degradation associated with natural thermal cracking. However, a systematic approach has not been developed to implement optimum application of this technique in AC pavements. This paper summarizes national knowledge about the application of precut technique in pavements, and presents three case studies in controlling thermal cracking in AC pavements in Interior Alaska. These three case studies included (1) Phillips Field Road precut in 1984, (2) Richardson Highway precut in 2012, and (3) Parks Highway precut in 2014. Precut variables were introduced including three precut spacing intervals, five precut depths, and five pavement structures. It was found based on yearly road surveys that the precutting treatment appeared promising to control thermal cracks. Shorter precut spacing along with stronger and/or thicker pavement structures looked promising with respect to crack control. Results also suggested that there may have an optimum precut depth that produces the best crack reduction effect. Preliminary cost analysis of precutting treatments indicated precutting to be an economically promising way of controlling natural thermal cracks. Continuing evaluation and monitoring of these test sections are needed to recommend (with increased confidence) the best design methodology and construction practice for Alaska and cold areas of other northern states.