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This paper documents a study of the dynamic mechanical responses of rigid pavement at the joint under moving aircraft loads. The MRC (pavement constructed on conventional base) section of Construction Cycle 2 test pavement at FAA's National Airport Pavement Test Facility was modeled with the three-dimensional finite element program ABAQUS. The model was calibrated by determining pavement damping parameters and joint stiffness values on the basis of heavy weight deflectometer data and strain profiles captured from dynamic sensors installed within the pavement at various locations. The effect of moving aircraft under varying speeds on tensile strains at the bottom of the portland cement concrete at the joint (εcritical) and dynamic stress-based load transfer efficiency [LTE (S)] at the joint is studied with three-dimensional finite element analysis. A decrease in εcritical at the joint with increasing speed was observed. The dynamic LTE (S) at the joint was enhanced at higher speeds. Sensitivity of dynamic LTE (S) at the joint to pavement damping was also studied with the finite element model. The dynamic LTE (S) at the joint increased with pavement damping. Finally, the effect of aircraft load and wheel configuration on dynamic LTE (S) was studied. Dynamic LTE (S) was sensitive to aircraft wheel configuration; however, it was insensitive to the magnitude of load.

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FAA uses a mechanistic design procedure, FAA Rigid and Flexible Iterative Elastic Layer Design (FAARFIELD), for the design of rigid airport pavements. FAARFIELD does not consider curling stresses in determining the portland cement concrete (PCC) layer thickness and assumes constant stress-based load transfer efficiency [LTE (S)] of 0.25 at the joints. Recently completed studies have shown that LTE (S) values under moving aircraft loads can be significantly higher than 0.25. In addition, the curling stresses, induced because of the temperature differentials at the top and bottom of the PCC slab, can affect the load transfer efficiency at the joint. Higher curling stresses can lead to higher combined stresses (loading plus curling) in pavements. The objective of this study is to analyze the effect of load transfer efficiency and loading intensity on PCC design thickness and the effect of PCC temperature gradient on LTE (S) and critical edge stresses. The results indicate that for a slab that shows no curling, an increase in LTE (S) value by 0.10 would reduce the PCC design thickness by 1.3 in. (33 mm) under FAA design procedures. In addition, when the top of the slab has a higher temperature than does the bottom of the slab, higher stresses at the joint and higher LTE (S) are observed. The variations in temperature gradient induce curling stresses in the slab and affect the LTE (S) at the joints.