Load-Transfer Efficiencies of Rigid Airfield Pavement Joints Based on Stresses and Deflections

Abstract

Load-transfer efficiency (LTE) of jointed concrete pavement is typically measured by the ratio of unloaded and loaded slab deflection. However, the maximum tensile stress in a slab is one of the critical mechanical responses that influences the performance of the jointed concrete pavement. Therefore, stress-based load-transfer efficiency, defined as stress reduction in the loaded slab because of the presence of an adjacent unloaded slab, is often considered an appropriate way to quantify LTE. Strain gauge data from full-scale tests collected by the Federal Aviation Administration were analyzed to compute the stress-based LTE of joints under moving loads. The effect of static aircraft gear loads and slab size on the LTE of joints was analyzed by using a two-dimensional finite-element program. FEM-calculated stress-based LTE under static aircraft loading on average was 38% lower than that measured under moving loads. LTE values were similar under various gear positions, gear configurations, and different slab sizes.