Relationship of Field versus Laboratory Compaction to Hot- and Warm-Mixed Asphalt Rutting Performance

Abstract

Rutting is a major distress for asphalt pavements. This paper examines the relationship of laboratory- and field-compaction methods to rutting performance based on aggregate packing characteristics. Four hot- and warm-mixed asphalts were produced and placed at full scale in test sections. Accelerated pavement testing (APT) to simulate military aircraft was utilized to assess mixture rutting performance. Cores from the test sections were used for laboratory testing. A plant-produced mixture was used for laboratory compaction of test specimens. Laboratory rut testing was conducted with the Asphalt Pavement Analyzer utilizing unique test conditions and with the Hamburg loaded wheel tracker under standard test conditions. Results indicated a large difference in performance between field- and laboratory-compacted test specimens: laboratory specimens performed much better than field-compacted ones. Aggregate microstructure analysis was performed for both field- and laboratory-compacted material using asphalt mixture imaging analysis software. Results indicated a large difference in aggregate packing as measured by total proximity zone length. The difference in aggregate packing was independent of bulk volumetric properties but had a large effect on mixture rutting performance.