Full-Scale Investigation of Load-Transfer Efficiency and Void Detection in Precast Prestressed Concrete Airfield Pavements

This full-scale study evaluates load-transfer efficiency (LTE) across joint types and boundary conditions in precast prestressed concrete airfield pavements and benchmarks void detection methods for postgrouting assessment. Fixed mortise-tenon joints achieved LTE of 0.75, approximately 25% higher than steel-glued bell-mouth joints (0.60). The postgrouting bond governed the measured load transfer, with only a 3.9% LTE decrease after removing all sliding devices. Transverse double tongue-and-groove joints in rectangular slabs exhibited high variability (coefficient of variation 32.27%), linked to inconsistent grouting. For voids, the deflection ratio method yielded a 0% detection rate despite visible uplift, whereas the load-deflection intercept method achieved 15.6% and aligned with ultrasonic shear wave tomography, which also quantified void areas (9.9% rectangular, 20.5% hexagonal). These findings highlight the critical importance of optimizing joint design and implementing strict grouting control. Furthermore, the adoption of a combined intercept-ultrasonic approach is recommended to ensure reliable postconstruction evaluation and maintenance.