Evaluation of Runway Bearing Capacity: In-Situ Measurements and Laboratory Tests

This paper describes the structural evaluation procedure for the new runway pavement of the Ancona Airport in Italy. As part of a major rehabilitation project, 520 m of runway were fully reconstructed along the “keel” section. The new pavement was constructed on a lime-stabilized subgrade. The base course had a lower cement stabilized layer and an upper hot mix asphalt layer. Modified binder was employed in all bituminous mixes, including the SMA wearing course. An extensive experimental program was carried out as part of the construction control activities. Dynamic Cone Penetrometer (DCP), static and light-weight dynamic plate tests were performed to estimate subgrade and foundation stiffness. Global pavement response was evaluated using deflection testing (HWD). A laboratory test program was completed to carefully assess physical and mechanical characteristics of pavement materials. In particular stiffness and fatigue properties of the asphalt layers were evaluated both on cores and laboratory compacted specimens. The analytical evaluation of the pavement strength was carried out using effective material properties for modulus and fatigue. Results were compared with calculations based on conventional FAA criteria. The study confirmed that an enhanced behavior of asphalt mixes, related to the use of modified binder, can be anticipated.