Evaluation of the Mechanical Properties of Field- and Laboratory-Compacted Hot-Mix Asphalt

The aim of this study is to investigate the effects of field-compaction conditions on the mechanical properties of asphalt concrete and then compare the properties with those of the specimens prepared with different Marshall hammer-blow numbers and gyratory-compactor gyrations. For this purpose, a binder layer was constructed with different compaction levels at different temperatures over a preconstructed plant-mix base layer. The B 70/100 bitumen and dense-graded limestone aggregate with a maximum size of 25.4 mm were used. The binder layer was divided into 12 sections, which were constructed with four different road roller-pass numbers and three different temperatures. The laboratory compaction conditions simulating all of the field compactions were assessed in indirect tensile strength, indirect tensile stiffness modulus, indirect tensile repeated load, and dynamic-creep tests. It was concluded that the field and laboratory specimens were affected by the compaction level and temperature in different ways. Furthermore, they exhibited different performances even with the same air-void contents. The laboratory specimens with the same air-void contents as those of field specimens displayed much better performance than the field specimens. (C) 2014 American Society of Civil Engineers.